JP2004005469A - Control method and control device for electric motor - Google Patents

Abstract

An object of the present invention is to provide a control method and a control device for an electric motor that reduce vibrations generated due to low rigidity of a control target, secure vibration suppression performance regardless of a command pattern and characteristics of the control target, and realize high positioning accuracy. .
A motor control method according to the present invention includes a command input step of inputting a command to a motor or a load connected to the motor, a characteristic of reducing a gain of a predetermined frequency and a frequency near the predetermined frequency, and a high frequency range. A pre-filtering step of applying a command to a filter having characteristics that suppress the gain of the filter to output a following command value, and command following control for controlling the state quantity of the electric motor or the load to follow the following command value. And
[Selection diagram] Fig. 1

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a control method and a control device for a motor that suppresses vibration of the motor or the control target, which is generated due to low mechanical rigidity of a control target of the motor or a connecting shaft that connects the motor and the control target. About.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in positioning control using an electric motor, digital servo control using a microcomputer has been performed. 1993 IEEJ National Convention No. 1759, "Control of Torsional Vibration of Reduction Gear", discloses a conventional motor control device for suppressing vibration.
A conventional motor control device will be described. FIG. 26 is a configuration diagram of a conventional motor control device. In FIG. 26, 101 is a position command creation unit, 102 is an electric motor, 103 is a control target (load), 104 is a position detection unit, and 105 is a servo controller. The servo controller 105 has a position command input unit 106, a pre-filter unit 107, and a command follow-up control unit 108. The command follow-up controller 108 includes a position deviation calculator (subtractor) 109, a position controller 110, a speed calculator 111, a speed deviation calculator (subtractor) 112, a speed controller 113, and a current controller 114. s is a Laplace operator.
[0003]
The position command creating unit 101 creates a position command and inputs the position command to the position command input unit 106 of the servo controller 105. The position command input unit 106 sends the position command θM * to the command follow-up control unit 108 via the pre-filter unit 107. The control device of the conventional example controls the motor 102 so that the position of the control target (load) 103 connected to the motor (hereinafter referred to as “control target position θL”) matches the position command θ *. Device. In FIG. 26, the control target position θL cannot be detected. The position detection unit 104 detects the position of the electric motor 102 (hereinafter, referred to as “electric motor position θM”). The servo controller 105 controls the motor 102 so that the motor position θM matches the position command θ *. Thereby, the control device of the conventional example controls the electric motor 102 such that the control target position θL matches the position command θ *. The motor position θM and the control target position θL are controlled so as to quickly follow the position command θ *.
[0004]
In a control system in which the rigidity of the control target (load) 103 itself and the connecting shaft connecting the motor 102 and the control target 103 is high, the control device of the related art uses the control target position θL with high accuracy to match the position command θ *. So that the electric motor 102 can be controlled.
In a control system having a low rigidity of the control object 103 itself or a connecting shaft that connects the electric motor 102 and the control object 103 (including a control system that performs control with a high degree of accuracy such that the torsion of the connecting shaft cannot be ignored). A phase difference occurs between the position θL and the motor position θM, and torsional vibration of the connecting shaft is likely to occur. In a control device that controls the electric motor 102 so that the electric motor position θM matches the position command θ *, when the vibration due to the torsion of the connecting shaft occurs, the speed at which the control target position θL converges to the position command θ * becomes slow.
[0005]
In the conventional example, the pre-filter unit 107 receives the pattern of the position command θ * and changes it to a pattern θM * (motor position command) that does not excite the vibration of the control target position θL. The command following control unit 108 controls the motor 102 so that the motor position θM matches the motor position command θM *. The pre-filter unit 107 suppresses the vibration of the control target position θL, and increases the speed at which the motor position θM and the control target position θL converge on the position command θ *.
[0006]
A basic calculation flow in the conventional control device shown in FIG. 26 will be described. The position command input unit 106 inputs the position command created by the position command creation unit 101. The position command input unit 106 converts the input position command into units, generates and outputs a position command θ * that matches a unit system used for calculation in the servo controller 105.
The pre-filter unit 107 performs second-order differentiation of the position command θ * to obtain a predetermined coefficient 1 / (ωa ² ) Is calculated to calculate a vibration suppression compensation value. The pre-filter unit 107 generates the motor position command θM * by adding the position command θ * and the calculated vibration suppression compensation value, and outputs the generated motor position command θM *. Assuming that the anti-resonance frequency of the system from the torque output by the motor to the motor 102 is fr, preferably ωa = 2π · f (f is fr or a frequency near fr). The principle of suppressing the vibration by the pre-filter unit 107 will be described later.
[0007]
The flow of the internal calculation of the command following control unit 108 will be described in detail. The position deviation calculator (subtractor) 109 receives the motor position command θM * and the motor position θM, and calculates a motor position deviation ΔθM (= θM * −θM). The position control unit 110 outputs a speed command ωM * (= Kpp · ΔθM) using the position proportional gain Kpp.
The speed calculator 111 differentiates the motor position θM to calculate the motor speed ωM (= θM · s). The speed deviation calculator (subtractor) 112 receives the speed command ωM * and the motor speed ωM, and calculates a speed deviation ΔωM (= ωM * −ωM).
Speed control section 113 performs a proportional integral operation based on speed deviation ΔωM, and outputs torque command T *. The current control unit 114 controls the current value I flowing through the motor 102 so that the torque TM output by the motor 102 becomes T *.
[0008]
The principle of suppressing vibration by the pre-filter unit 107 will be described. A system in which the electric motor 102 moves the control target 103 is represented by a two-inertia system (the electric motor 102 and the control target 103) model (FIG. 27) which is generally used as a resonance system model. Actually, a system in which the torque TM moves the control target position θL may be represented by a complicated mathematical model.
[0009]
FIG. 28 is a block diagram showing, by a mathematical model, a system in which the electric motor 102 shown in FIG. 27 moves the control target 103 through the low-rigidity connection shaft. In FIG. 28, electric motor 102 generates actual torque TM with a sufficiently fast response in response to torque command T *. It is assumed that the transfer function from the input of the torque command T * to the generation of the actual torque TM is TM / T * = 1. JM is the inertia of the electric motor 102, JL is the inertia of the control target 103, and Ks is the spring constant of the connection shaft. The inertia of the connecting shaft is ignored because it is sufficiently smaller than JM and JL.
[0010]
When the transfer function θM / T * from the torque command T * to the electric motor position θM is obtained based on the mathematical model in FIG. 28, the equation (1) is obtained.
(JLs ² + Ks) / [｛JM / JLs ² + Ks (JM + JL)｝ s ² ] (1)
[0011]
When the transfer function θL / θM from the electric motor position θM to the control target position θL is obtained based on the mathematical model of FIG. 28, Expression (2) is obtained.
Ks / (JLs ² + Ks) (2)
[0012]
FIG. 29 is a block diagram expressed by a Laplace operator s equivalent to the configuration diagram of FIG. 26 using the equations (1) and (2) obtained from the block diagram of FIG. In FIG. 29, blocks denoted by the same reference numerals as in FIG. 26 have the same functions as in FIG.
In FIG. 29, when there is no pre-filter unit 107, the position command θ * = θM *. In FIG. 29, the transfer function from the motor position command θM * to the control target position θL and the transfer function from the position command θ * to the control target position θL are compared to determine whether or not the pre-filter unit 107 is provided. Explain the difference in response.
[0013]
The frequency characteristics of the transfer function when the pre-filter unit 107 is not provided, that is, from the motor position command θM * to the control target position θL in FIG. 29 will be described. The frequency characteristic of the transfer function from the torque command T * to the motor position θM in FIG. 29 is given by FIG. In FIG. 30A, the horizontal axis is frequency, and the vertical axis is gain and phase. The horizontal axis is logarithmic. In other frequency characteristic diagrams, the horizontal axis represents frequency, and the vertical axis represents gain and phase. The horizontal axis is logarithmic.
FIG. 30A has a resonance point and an anti-resonance point because the rigidity of the control target is low. In FIG. 30A, a frequency at which resonance occurs is called a resonance frequency, and a frequency at which anti-resonance occurs is called an anti-resonance frequency. The frequency characteristic of the transfer function of the system including the feedback loop from the motor position command θM * to the motor position θM is as shown in FIG.
The frequency characteristic of the transfer function from the motor position θM to the control target position θL is as shown in FIG. The frequency characteristics of the transfer function from the motor position command θM * to the control target position θL (response frequency characteristics of the control device without the pre-filter unit 107) are the same as those shown in FIGS. 30B and 30C. Thus, FIG. 30D is obtained. FIG. 30D has a gain peak at the anti-resonance frequency fr.
[0014]
FIG. 31A is a pattern of a motor position command θM * for instructing to shift the position of the motor 102 by a certain amount. The vertical axis represents the motor position command θM * (the amount of displacement of the position of the motor 102), and the horizontal axis represents time. This is a commonly used S-shaped command. FIG. 31B is a differential waveform of the electric motor position command θM * in FIG. 31A and has a trapezoidal pattern. FIG. 32 shows the response of the motor position deviation ΔθM and the response of the control target position deviation ΔθL, which is the difference between the control target position θL and the motor position command θM *. The position command output period in FIG. 32 indicates a period during which the motor position command θM * in FIG. 31 (a) fluctuates, that is, a period during which the differential value of the motor position command θM * in FIG. 31 (b) is not zero.
As shown in FIG. 32, after the completion of the output of the position command, the control target position deviation ΔθL vibrates more greatly than the motor position deviation ΔθM. When the vibration frequency of the control target position θL is measured, the vibration frequency is determined as the frequency at which the gain peak occurs in the frequency characteristic of the transfer function from the motor position command θM * to the control target position θL shown in FIG. ) Nearby frequencies. Due to the low rigidity of the shaft connecting the electric motor 102 and the control target 103, the control target position θL generates large vibration after the completion of the position command output.
[0015]
Next, the frequency characteristics of the transfer function when the pre-filter unit 107 is provided, that is, from the position command θ * to the control target position θL in FIG. 29 will be described. FIG. 30D shows the frequency characteristics of the transfer function from the motor position command θM * to the control target position θL. The frequency characteristic of the pre-filter unit 107 is as shown in FIG. 33A, where ωa = 2π · fr (fr is the anti-resonance frequency in FIG. 30A). The pre-filter unit 107 has a frequency characteristic in which the gain (gain) is minimized at the frequency ωa, and the gain increases as the frequency increases in a frequency higher than ωa. The frequency characteristic of the transfer function from the position command θ * to the control target position θL is as shown in FIG. 33B obtained by combining FIGS. 30D and 33A.
[0016]
FIG. 33 (b) is compared with FIG. 30 (d) which is a frequency characteristic of a transfer function from the position command to the control target position θL when the pre-filter unit 107 is not provided, and FIG. There is no gain peak at. That is, the pre-filter unit 107 reduces the gain peak at the anti-resonance frequency of the response characteristic of the control device.
FIG. 34 shows the response of the control target position deviation ΔθL and the motor position deviation ΔθM when the command pattern of the position command θ * is as shown in FIG. Compared with FIG. 32 which is a response when the pre-filter unit 107 is not provided, the vibration of the control target position θL after the completion of the output of the position command is reduced. 32 and 34 have the same configuration except for the pre-filter unit 107 in FIG.
[0017]
As described above, in the conventional control device, the pre-filter unit 107 in FIG. 26 reduces the gain peak occurring in the frequency characteristic of the transfer function from the position command θ * to the control target position θL. Thereby, the vibration of the control target position θL that occurs after the completion of the position command output due to the gain peak is reduced.
FIG. 35 shows the response characteristics when the parameter settings of the system having the response characteristics of FIG. 32 are partially changed. In the system shown in FIG. 35, the position proportional gain Kpp of the position control unit 110 and the speed proportional gain Kvp of the speed control unit 113 are reduced as compared with the system shown in FIG. Vibration after completion was reduced. In FIG. 35, the vibration amplitude after the completion of the output of the position command is substantially the same as in FIG. 34, but the response is slower than in FIG.
In the conventional control device, the pre-filter unit 107 has an effect that the vibration of the control target position θL after the completion of the position command output can be reduced while maintaining the high-speed response of the control device.
[0018]
[Patent Document 1]
JP-A-10-149210
[Patent Document 2]
JP-A-6-028006
[Non-patent document 1]
1993 IEEJ National Convention No. 1759 "Vibration suppression control of torsional vibration of reduction gear"
[0019]
[Problems to be solved by the invention]
In the conventional example, assuming that the position command θ * output from the position command input unit 106 in FIG. 29 has the pattern shown in FIG. 31A, the pre-filter unit 107 (the transfer function of which is the second derivative of the position command) Correction term (s ² / Ωa ² ). ) Are shown in FIG. 36. In FIG. 31B and FIG. 36, time points A, B, C, and D are the acceleration (second-order differentiation of the position command) fluctuation time point of the command pattern in FIG. At times A, B, C, and D, the second derivative of the motor position command θM * fluctuates rapidly. FIG. 37 shows a waveform of the torque command T * when the system shown in FIG. 29 receives the position command θ * of the command pattern of FIG.
[0020]
At times A, B, C, and D, a very large torque command T * indicated by a broken-line circle in FIG. 37 is generated due to a sudden change in the second derivative of the motor position command θM *. The larger the variation of the second derivative of the motor position command θM * at the time points A, B, C, and D, that is, the smaller ωa or the greater the acceleration of the position command θ *, the more the time points A, B, C, and D , A large torque command T * is generated. Generally, an upper limit is set for the torque command T * due to hardware restrictions or the like. The torque T * is limited so as not to be larger than the upper limit. If the variation of the second derivative of the motor position command θM * at the time points A, B, C, and D becomes an excessive value, the torque command T * is limited. If the torque command T * is limited, the control device cannot output an appropriate torque waveform for suppressing vibration while maintaining a high-speed response, and there is a problem that it takes time to converge the vibration of the control target position θL. Was.
[0021]
The present invention provides a control device having low mechanical rigidity, such as a control target (load) itself or a connecting portion between a motor and a control target, which maintains a high-speed response of vibrations of the motor and the control target regardless of a command pattern and characteristics of the control target. It is an object of the present invention to provide a control method and a control device for an electric motor that suppresses the electric current constantly. Specifically, an object of the present invention is to provide a control method and a control device for an electric motor that prevent a torque command from becoming an excessive value and being limited regardless of a command pattern and characteristics of a control target. I do.
According to the present invention, according to the state quantity of the control system (according to variation in characteristics of individual control devices (including controlled objects), aging, and / or differences in history leading to the state quantity), the present invention is automatically applied. It is an object of the present invention to provide a control method and a control device for a motor that always optimally suppress vibration of the motor and the control target.
[0022]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following configurations.
An electric motor control method according to one aspect of the present invention includes a command input step of inputting a command to an electric motor or a control target connected to the electric motor, a characteristic of lowering a gain of a predetermined frequency and a frequency near the predetermined frequency, and A pre-filtering step of applying the command to a filter having a characteristic of suppressing the gain of the band and outputting a follow-up command value, and a command for controlling the state quantity of the electric motor or the control target to follow the follow-up command value. Following control step.
[0023]
A control device for a motor according to another aspect of the present invention includes a command input unit for inputting a command to a motor or a control target connected to the motor, a characteristic of reducing a gain of a predetermined frequency and a frequency near the predetermined frequency, and A filter having both characteristics of suppressing the gain of the band, a pre-filter unit that outputs the following command value by applying the command to the filter, and the following command value is a state quantity of the electric motor or the control target. And a command follow-up control unit that controls to follow up.
[0024]
The motor control method and the control device according to the present invention have an effect of suppressing vibration of the motor and the control target caused by low rigidity of the control target itself or a connection shaft connecting the motor and the control target. Play. ADVANTAGE OF THE INVENTION According to this invention, the vibration of an electric motor and a controlled object can always be suppressed regardless of the command pattern or the characteristic of a controlled object. The present invention realizes a control method and a control device for an electric motor that prevent a torque command from becoming an excessive value and being limited regardless of a command pattern and characteristics of a control target.
[0025]
According to another aspect of the present invention, there is provided a control method of a motor, comprising: a command inputting step of inputting a command to a motor or a control target connected to the motor; a characteristic of reducing a gain of a predetermined frequency and a frequency near the predetermined frequency; The transfer function of the filter having the characteristic of suppressing the gain of the band is equivalently converted into the sum of a constant term and a feedforward compensation term, the command is applied to the constant term to output a follow-up command value, and the command On the feedforward compensation term to output a feedforward compensation term compensation amount, based on the feedforward compensation term compensation amount and the following command value, the motor command or the following command value based on the following command value. And a command following control step of controlling the state quantity of the controlled object to follow.
[0026]
A control device for a motor according to another aspect of the present invention includes a command input unit for inputting a command to a motor or a control target connected to the motor, a characteristic of reducing a gain of a predetermined frequency and a frequency near the predetermined frequency, and The transfer function of the filter having the characteristic of suppressing the gain of the band is equivalently converted into the sum of a constant term and a feedforward compensation term, the command is applied to the constant term to output a follow-up command value, and the command On the feedforward compensation term to output a feedforward compensation term compensation amount, based on the feedforward compensation term compensation amount and the following command value, the motor command or the following command value based on the following command value A command following control unit that controls the state quantity of the control target to follow.
[0027]
The motor control method and the control device according to the present invention have an effect of suppressing vibration of the motor and the control target caused by low rigidity of the control target itself or a connection shaft connecting the motor and the control target. Play. ADVANTAGE OF THE INVENTION According to this invention, the vibration of an electric motor and a controlled object can always be suppressed regardless of the command pattern or the characteristic of a controlled object. The present invention realizes a control method and a control device for an electric motor that prevent a torque command from becoming an excessive value and being limited regardless of a command pattern and characteristics of a control target.
[0028]
In a command following control step (command following control unit), control is performed using a command value based on a constant term as a following target value of the electric motor. The vibration of the control target (load) is suppressed based on the feedforward compensation term compensation amount. For example, in the configuration of the first embodiment (FIG. 1), the position command θ * input by the filter unit is processed, and control is performed using the motor position command θM *, which is the calculation result, as a target value. In the arithmetic processing of (1), a digit loss occurs for a component less than 1 LSB. This calculation error causes a convergence value error of the motor position. According to the invention of the above aspect, since the position command θ * is controlled as it is as the target value (the target value is not processed), no convergence value error of the motor position due to the calculation error occurs. There is no need to compensate for the convergence value error of the motor position. According to the present invention, it is possible to control the electric motor with higher accuracy than when a convergence value error occurs. According to the present invention, as compared with the case where error compensation is performed, the calculation time of error compensation in software processing can be shortened, and the labor and time for developing error compensation software during product development can be reduced.
[0029]
According to another aspect of the present invention, there is provided a method for controlling a motor, comprising: a command input step of inputting a command to a motor or a control target connected to the motor; and a feedforward compensation term compensation amount and a following command value. A command following control step for controlling the state quantity of the electric motor or the control target to follow the following command value based on the following command value, and a command estimation for outputting an estimation command based on the state quantity inside the command following control step. Step, the characteristic of lowering the gain of the predetermined frequency and the frequency in the vicinity thereof, and the transfer function of the filter having the characteristic of suppressing the gain in the high frequency band, equivalently converted to the sum of a constant term and a feedforward compensation term, An internal configuration type pre-fill that outputs an estimated amount of the feedforward compensation term by applying an estimation command to the feedforward compensation term Has a step, a.
[0030]
A control device for a motor according to another aspect of the present invention includes a command input unit that inputs a command for a motor or a control target connected to the motor, and a feedforward compensation term compensation amount and a following command value, based on the command. A command following control unit that controls the state quantity of the electric motor or the control target to follow the following command value based on the following command value, and a command estimation that outputs an estimation command that estimates the command based on a state quantity inside the command following control unit. And a transfer function of a filter having both a characteristic of lowering the gain of a predetermined frequency and a frequency in the vicinity thereof, and a characteristic of suppressing a high-frequency gain, is equivalently converted to a sum of a constant term and a feedforward compensation term, An internal configuration type pre-filter unit that outputs the feedforward compensation term compensation amount by applying an estimation command to the feedforward compensation term.
[0031]
The motor control method and the control device according to the present invention have an effect of suppressing vibration of the motor and the control target caused by low rigidity of the control target itself or a connection shaft connecting the motor and the control target. Play. ADVANTAGE OF THE INVENTION According to this invention, the vibration of an electric motor and a controlled object can always be suppressed regardless of the command pattern or the characteristic of a controlled object. The present invention realizes a control method and a control device for an electric motor that prevent a torque command from becoming an excessive value and being limited regardless of a command pattern and characteristics of a control target.
[0032]
In a command following control step (command following control unit), a command value is used as a following target value of the electric motor. The vibration of the control target (load) is suppressed based on the feedforward compensation term compensation amount. As a result, a convergence value error of the motor position due to the cancellation in the calculation does not occur. There is no need to compensate for the convergence value error of the motor position. ADVANTAGE OF THE INVENTION The control method and control apparatus of this invention have high positioning accuracy of a motor compared with the case where calculation error compensation is not performed. Advantageous Effects of Invention The present invention can reduce the operation time for compensating for a calculation error in software processing as compared with the case where the calculation error is compensated, and also reduce the labor and time for developing the calculation error compensation software during product development. it can. Alternatively, a calculation error compensation circuit is not required in the control LSI.
[0033]
For example, in a control method in which basic software is configured by an existing control program, or in a control device in which a basic circuit is configured by an existing control LSI, a program for suppressing vibration of a control target (load). Alternatively, there are various restrictions when adding a circuit (the degree of freedom in configuration is limited). For example, in many cases, the value of the command input by the command input step (command input unit) cannot be taken out to the outside (the value of the input command is unknown). The present invention does not change the basic control system. In the present invention, the value of the input command is estimated, the feedforward compensation amount is calculated based on the estimated command, and the output of the motor is corrected by adding the feedforward compensation amount.
The present invention relates to, for example, an electric motor and a control system which are generated due to low rigidity of a control object itself or a connection shaft connecting the electric motor and the control object in a control device in which a basic circuit is configured by an existing control LSI. A control method and control device for a motor that effectively suppresses vibration of an object are realized.
[0034]
In the above-described motor control method according to another aspect of the present invention, the pre-filtering step, the feed-forward type pre-filtering step or the internal configuration type pre-filtering step includes the steps of: Among the characteristics for lowering the gain, the gain at the predetermined frequency is made variable.
In the above-described motor control device according to another aspect of the present invention, the pre-filter unit, the feed-forward type pre-filter unit or the internal configuration type pre-filter unit includes a predetermined frequency and a frequency near the predetermined frequency. Among the characteristics for lowering the gain, the gain at the predetermined frequency is made variable.
The motor control method and control device of the present invention further improve the vibration suppression effect by making the gain of a predetermined frequency variable. The gain of the predetermined frequency may be automatically changed.
[0035]
In the above-described electric motor control method according to another aspect of the present invention, the pre-filtering step, the feed-forward type pre-filtering step or the internal configuration type pre-filtering step has a characteristic that suppresses the high-frequency gain. It changes depending on the operating state.
In the above-described motor control device according to another aspect of the present invention, the pre-filter unit, the feed-forward type pre-filter unit or the internal configuration type pre-filter unit has a characteristic that suppresses the high-frequency gain. It changes depending on the operating state.
The motor control method and control device of the present invention automatically adjust the characteristic for suppressing the high-frequency gain according to the operating state of the motor or the control target. This reduces the response delay of the control device due to the suppression of the high-frequency gain.
[0036]
In the above-described electric motor control method according to another aspect of the present invention, the pre-filtering step, the feed-forward type pre-filtering step or the internal configuration type pre-filtering step has a characteristic that suppresses the high-frequency gain. , At least based on the parameter for determining the predetermined frequency.
In the above-described motor control device according to another aspect of the present invention, the pre-filter unit, the feed-forward type pre-filter unit or the internal configuration type pre-filter unit has a characteristic that suppresses the high-frequency gain. , At least based on the parameter for determining the predetermined frequency.
The motor control method and control device of the present invention automatically determine a characteristic that suppresses high-frequency gain together with a predetermined frequency. Thereby, the operability of the control device is improved.
[0037]
In the above-described electric motor control method according to another aspect of the present invention, the pre-filtering step, the feed-forward type pre-filtering step or the internal configuration type pre-filtering step includes a step of automatically setting the predetermined frequency. It has a frequency automatic setting step.
In the above-described electric motor control device according to another aspect of the present invention, the pre-filter unit, the feed-forward type pre-filter unit or the internal configuration type pre-filter unit may be configured to automatically set the predetermined frequency. It has an automatic frequency setting unit.
The electric motor control method and control device of the present invention automatically set a predetermined frequency for each control device. ADVANTAGE OF THE INVENTION The control method and control apparatus of the electric motor of this invention perform optimal control adaptively, and suppress the vibration of an electric motor and a control object, even when the characteristic of a control system changes with time or environmental conditions. Thereby, the operability of the control device is improved.
[0038]
In the above-described electric motor control method according to another aspect of the present invention, the vibration frequency automatic setting step includes: a vibration detection step of detecting a vibration of the control target; and extracting a vibration frequency from the detected vibration. And a frequency determining step of determining the frequency.
In the above-described electric motor control device according to another aspect of the present invention, the vibration frequency automatic setting unit extracts a vibration frequency from the detected vibration, And a frequency determination unit that determines the frequency of
[0039]
The electric motor control method and control device of the present invention accurately detect the vibration frequency of the control target by detecting the vibration of the control target. ADVANTAGE OF THE INVENTION The control method and control apparatus of the electric motor of this invention can always reduce the vibration of a controlled object optimally even if the vibration frequency changes by the characteristic fluctuation of a controlled object.
The method of detecting the vibration of the control target is arbitrary. For example, a vibration detection sensor composed of a pressure sensor is attached to the surface of the control target. Thus, the vibration frequency of the control target can be accurately detected. Operability of the control device is improved.
[0040]
In the above-described electric motor control method according to another aspect of the present invention, the vibration frequency automatic setting step determines the predetermined frequency based on a vibration frequency of the electric motor.
In the above-described electric motor control device according to another aspect of the present invention, the vibration frequency automatic setting unit determines the predetermined frequency based on the vibration frequency of the electric motor.
The motor control method and control device of the present invention accurately detect the vibration frequency of the motor by detecting the vibration of the motor. ADVANTAGE OF THE INVENTION The control method and control apparatus of the electric motor of this invention can always reduce the vibration of an electric motor optimally even if the vibration frequency changes by the characteristic fluctuation of an electric motor.
[0041]
In the above-described motor control method according to another aspect of the present invention, in the vibration frequency automatic setting step, a mathematical model of the motor and the control target is estimated based on a response of the motor, and the predetermined model is determined based on the mathematical model. Is determined.
In the above-described motor control device according to another aspect of the present invention, the vibration frequency automatic setting unit estimates a mathematical model of the motor and the control target based on a response of the motor, and determines the predetermined model based on the mathematical model. Is determined.
[0042]
The motor control method and control device of the present invention estimate a motor and a mathematical model of a control target, and accurately detect a vibration frequency of the control target. ADVANTAGE OF THE INVENTION The control method and control apparatus of the electric motor of this invention can always reduce the vibration of a controlled object optimally even if the vibration frequency changes by the characteristic fluctuation of a controlled object. Operability of the control device is improved. The electric motor control method and control device of the present invention are inexpensive because they do not use a vibration detection unit to be controlled.
[0043]
In the above-described motor control method according to another aspect of the present invention, the predetermined frequency is a frequency near an anti-resonance frequency of a system from the torque output by the motor to the position or speed of the motor.
In the above-described motor control device according to another aspect of the present invention, the predetermined frequency is a frequency near an anti-resonance frequency of a system from the torque output by the motor to the position or speed of the motor.
The motor control method and control device of the present invention suppresses system vibration until the torque output by the motor is transmitted to the control target, and realizes a control method and control device having high responsiveness. The frequency near the anti-resonance frequency is a frequency that is the same as or approximate to the anti-resonance frequency.
[0044]
According to another aspect of the present invention, there is provided a method for controlling an electric motor, comprising: a command inputting step of inputting a command to a motor or a control target connected to the motor; and a state quantity of the motor or the control target following the command. Control step to control, wherein in the control step, the characteristic of lowering the gain of the frequency near the anti-resonance frequency of the system from the torque of the motor to the position or speed of the motor, and gain in the high frequency range The following characteristic is output by applying the command to a filter having both the suppressing characteristic and the following command, and the same or equivalent characteristic as controlling the state quantity of the electric motor or the control target to follow the following command value is provided. Is performed.
[0045]
A motor control device according to another aspect of the present invention includes a command input unit that inputs a command to a motor or a control target connected to the motor, and a state quantity of the motor or the control target follows the command. And a control unit for controlling, wherein the control unit has a characteristic of reducing a gain of a frequency near an anti-resonance frequency of a system from a torque of the electric motor to a position or a speed of the electric motor, and a high-frequency gain. The following characteristic is output by applying the command to a filter having both the suppressing characteristic and the following command, and the same or equivalent characteristic as controlling the state quantity of the electric motor or the control target to follow the following command value is provided. Is performed.
[0046]
The motor control method and the control device according to the present invention have an effect of suppressing vibration of the motor and the control target caused by low rigidity of the control target itself or a connection shaft connecting the motor and the control target. Play. ADVANTAGE OF THE INVENTION According to this invention, the vibration of an electric motor and a controlled object can always be suppressed regardless of the command pattern or the characteristic of a controlled object. The present invention realizes a control method and a control device for an electric motor that prevent a torque command from becoming an excessive value and being limited regardless of a command pattern and characteristics of a control target.
[0047]
An apparatus according to another aspect of the present invention has the above-described control device. The device of the present invention achieves high responsiveness.
[0048]
BEST MODE FOR CARRYING OUT THE INVENTION
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that specifically show the best mode for carrying out the present invention will be described below with reference to the drawings.
[0049]
<< Embodiment 1 >>
First Embodiment A control method and a control device for a motor according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a configuration of a motor control device according to Embodiment 1 of the present invention. The control device for the electric motor according to the first embodiment is configured to automatically mount an electronic component (for example, an IC) taken out of a cartridge onto a printed circuit board. This is a control device that controls the position of the holding mechanism unit until it is placed at the position. The application target of the motor control device and the control method of the present invention is not limited to this, and can be applied to any device. In the control device for the electric motor according to the first embodiment, the mechanical rigidity of the connecting portion between the electric motor 2 and the control target 3 is low. The rigidity of the control target (load) 3 itself may be low.
[0050]
In FIG. 1, reference numeral 1 denotes a position command creation unit, 2 denotes an electric motor, 3 denotes a control target (load), 4 denotes a position detection unit, 5 denotes a vibration detection unit, and 6 denotes a servo controller. The servo controller 6 has a position command input unit 7, a pre-filter unit 8, and a command follow-up control unit 12. The pre-filter unit 8 includes a filter unit 9 and an automatic parameter setting unit 10. The command follow-up controller 12 includes a position deviation calculator (subtractor) 13, a position controller 14, a speed calculator 15, a speed deviation calculator (subtractor) 16, a speed controller 17, and a current controller 18.
[0051]
The position command creating unit 1 creates a position command and inputs it to the position command input unit 7 of the servo controller 6. The position command input unit 7 sends the position command θ * to the command follow-up control unit 12 via the pre-filter unit 8. The control device of the first embodiment controls electric motor 2 such that the position of control target (load) 3 connected to the electric motor (hereinafter, referred to as “control target position θL”) matches position command θ *. It is a device for. In FIG. 1, the control target position θL cannot be detected. The position detector 4 detects the position of the electric motor 2 (hereinafter, referred to as “electric motor position θM”). The servo controller 6 controls the motor position θM to follow the position command. Since the control target 3 is connected to the electric motor 2, the control target position θL also follows the position command.
[0052]
The position command input unit 7 receives the position command, converts it into a unit suitable for internal calculation, and outputs it as a position command θ *. The servo controller 6 controls the motor 2 so that the motor position θM matches the position command θ *. Thus, the control device of the first embodiment controls electric motor 2 such that control target position θL matches position command θ *. The motor position θM and the control target position θL are controlled so as to quickly follow the position command θ *. In the control device according to the first embodiment in which the rigidity of the control target 3 or the connecting shaft that connects the electric motor 2 and the control target 3 is low, the control target position θL is likely to vibrate. In order to suppress the vibration of the control target position θL, the pre-filter unit 8 inputs a pattern of the position command θ * and changes the pattern to a pattern θM * (motor position command) that does not excite the vibration of the control target position θL. The command following controller 12 controls the motor 2 so that the motor position θM detected by the position detector 4 follows the motor position command θM *. The control device quickly follows the input position command.
[0053]
The first embodiment of FIG. 1 is different from the conventional motor control device (FIG. 26) in that a vibration detection unit 5 is added and that the internal structure of a pre-filter unit 8 is different from that of FIG. This is different from the filter unit 107.
The vibration detection unit 5 directly detects the vibration of the control target 3 and transmits the vibration to the parameter automatic setting unit 10 of the pre-filter unit 8. The configuration of the vibration detection unit 5 is optional. The vibration detection unit 5 according to the first embodiment is a pressure-sensitive sensor attached to the surface of the control target 3.
The pre-filter unit 8 has an automatic parameter setting unit 10, and the transfer function of the filter unit 9 is different from that of the pre-filter unit 107. The parameter automatic setting unit 10 receives an output signal of the vibration detection unit 5 and extracts a vibration frequency of the control target 3 included therein. The parameter automatic setting unit 10 determines a characteristic (transfer function) of the filter unit 9 based on the extracted vibration frequency.
[0054]
The effects obtained by this difference in configuration will be described below. The conventional motor control method has an effect of suppressing vibration of the motor position θM and the control target position θL in a control system in which the rigidity of the control target 103 or the connecting shaft connecting the motor 102 and the control target 103 is low. However, depending on the command pattern created by the position command creation unit 101 or the characteristics of the control target 103, the torque command T * becomes excessively large and it is necessary to apply a torque limit. In this case, the control device cannot perform the optimal control, and the response to the position command becomes slow, and there is a problem that it takes time to converge the vibration of the control target position θL.
[0055]
The filter unit 9 of the pre-filter unit 8 in FIG. 1 receives the position command θ *, automatically converts the position command θ * into a command pattern that hardly excites vibration in the control target 3, and outputs the command pattern as the motor position command θM *. Regardless of the command pattern created by the position command creation unit 1 and the characteristics of the control target 3, the motor position command θM * never exceeds the upper limit (the limit is not applied). The control device according to the first embodiment executes a control method that always suppresses the vibration of the electric motor 2 and the control target 3 optimally.
[0056]
Next, a detailed operation of the control block of FIG. 1 will be described. The position command creation unit 1 is configured by, for example, a PLC (Programmable Logic Controller). The position command creating unit 1 creates a position command pattern and outputs a position command according to the pattern.
The position detector 4 detects the position of the electric motor 2 and outputs it as the electric motor position θM.
The servo controller 6 performs digital control. The servo controller 6 inputs the position command from the position command creating unit 1 and the motor position θM from the position detecting unit 4 at regular intervals, performs arithmetic processing, and controls the current I flowing through the motor 2.
[0057]
FIG. 2 shows a flowchart of a one-cycle calculation process executed by the servo controller 6. The servo controller 6 repeats the calculation processing shown in FIG. 2 at a constant calculation cycle (for example, 166 μs). The processing from the start to the end of FIG. 2 will be described with reference to FIGS. The subscript (n) of each state quantity represents the value in the current computation cycle, and (n-1) represents the value in the previous computation cycle.
The position command input unit 7 reads the position command from the position command creation unit 1, converts the read position command into a unit system suitable for the internal calculation of the servo controller 6, and outputs a position command θ * (n) (command acquisition in step S1). Processing).
The command follow-up control unit 12 captures the position of the electric motor 2 detected by the position detection unit 4 as θM (n) (state quantity capture processing in step S2).
[0058]
The automatic parameter setting unit 10 of the pre-filter unit 8 calculates the vibration frequency fr from the vibration of the control target 3 detected by the vibration detection unit 5 (pre-filter parameter automatic setting process in step S3). Let ωa = 2π · fr. The method by which the parameter automatic setting unit 10 calculates the vibration frequency of the control target 3 is arbitrary. For example, the parameter automatic setting unit 10 measures a zero-crossing time interval of a vibration signal output from the vibration detection unit 5, and calculates a vibration frequency from the measured value. For example, the automatic parameter setting unit 10 detects a vibration frequency fr by converting a vibration signal output from the vibration detection unit 5 into a frequency spectrum by FFT (fast Fourier Transform). The parameter automatic setting unit 10 sets ωa = 2π · fr based on the calculated vibration frequency fr, and determines ωf based on ωa.
[0059]
FIG. 3 is a graph showing the relationship between ωa and ωf in the control device according to the first embodiment. The parameter automatic setting unit 10 determines ωf based on ωa using a table that stores values obtained by plotting ωa and ωf in the graph shown in FIG. 3 or a function representing the graph in FIG. A two-dimensional table may be used in which ωa and the acceleration (second derivative) of the position command θ * are used as arguments. The damping coefficient ζ may be variable, but is fixed at 1 here. The damping coefficient ζ is a non-zero value. A detailed description of the role of ωf, the reason why ωa and the acceleration of the position command θ * are used as arguments, and an appropriate setting value of ζ will be given later. Thus, the parameter automatic setting unit 10 determines the parameters of the filter unit 9.
[0060]
The filter unit 9 calculates a motor position command θM * (n) from the position command θ * (n) using ωa and ωf (pre-filter processing in step S4). The filter unit 9 has a transfer function shown in FIG. FIG. 4A is a diagram illustrating a frequency characteristic of a transfer function between input and output of the filter unit 9. The frequency characteristics of the filter unit 9 follow the parameters determined in step S3. The filter section 9 has a characteristic of lowering the gain of the frequency ωa and the frequency in the vicinity thereof. In particular, the gain higher than ωa is lower than the frequency characteristic of the pre-filter unit 107 of the conventional example shown in FIG. The frequency characteristic from the position command θ * to the control target position θL is a combination of FIG. 30 (d) and FIG. 4 (a), and is as shown in FIG. 4 (b). FIG. 4B shows that the gain in the higher frequency range than ωa is suppressed as compared with FIG. 33B of the conventional example.
FIG. 5 is a diagram showing the internal configuration of the filter unit 9 in an expression using a Laplace operator s. Actually, the configuration of FIG. 5 is converted into a digital filter by a method such as bilinear conversion, and the filter unit 9 realizes the characteristics of FIG. 4A as a digital filter. A detailed description of the effect of step S4 will be given later.
[0061]
The position deviation calculator (subtractor) 13 and the position controller 14 perform a position control process (the position control process in step S5). First, the position deviation calculator 13 calculates ΔθM (n) = θM * (n) −θM (n) to calculate the motor position deviation ΔθM (n). The position control unit 14 calculates ωM * (n) = Kpp · ΔθM (n) using the position proportional gain Kpp to calculate the speed command ωM * (n).
[0062]
The speed calculator 15, the speed deviation calculator (subtractor) 16, and the speed controller 17 perform a speed control process (speed control process in step S6). First, the speed calculator 15 calculates the speed ωM (n) of the electric motor 2 based on the electric motor position θM. The method by which the speed calculation unit 15 calculates the speed ωM (n) is arbitrary. The speed calculation unit 15 calculates the speed ωM (n) by a technique such as a reverse difference of the motor position θM, differentiation of the motor position θM using bilinear transformation, or a speed observer. Next, the speed deviation calculator 16 calculates ΔωM (n) = ωM * (n) −ωM (n) to calculate the speed deviation ΔωM (n). Next, the speed control unit 17 calculates the torque command T * (n) using the speed proportional gain Kvp and the speed integration time constant Tvi by performing the proportional integral calculation of Expressions (3) and (4). Xvi (n) is a variable for integration calculation.
[0063]
Xvi (n) = Xvi (n-1) + ΔωM (n) · Kvp / Tvi (3)
T * (n) = Kvp · ΔωM (n) + Xvi (n) (4)
[0064]
The current control unit 18 controls so that a current corresponding to the torque command T * (n) flows through the electric motor 2 (current control processing in step S7). Thus, the processing illustrated in FIG. 2 is completed.
[0065]
In the flowchart of FIG. 2, the effect of the pre-filtering process in step S4, the role of ωf derived in step S3, and the reason for deriving ωf using ωa and the acceleration (second derivative) of position command θ * as arguments , Ζ will be described in comparison with a conventional example.
First, the effect of the pre-filter processing in step S4 will be described. The filter unit 9 shown in FIG. 5 has a configuration in which a block 1 having the same transfer function as the pre-filter unit 107 (FIG. 26) of the conventional example and a block 2 as a secondary filter are connected in series. Block 1 removes a frequency component that excites the vibration of the control target position θL from the position command θ *. Block 1 has an effect of reducing the vibration of the control target position θL. Since the detailed principle is the same as that of the conventional example, the description is omitted.
[0066]
Block 2 prevents the torque command T * from becoming an excessive value at the time of the acceleration (second-order differential) fluctuation of the position command θ *. FIG. 6 is a diagram showing a waveform of the position command θ * input by the pre-filter unit 8 (FIG. 1) and a waveform of the motor position command θM * output (the horizontal axis is time, the vertical axis is the position command θ * and the motor position). Command θM *). The broken line is the position command θ *, and the solid line is the motor position command θM *. The waveform of the position command θ * is the same as the waveform shown in FIG. The first derivative of the position command θ * has a waveform shown in FIG. At this time, the waveform of the torque command T * output by the speed control unit 17 (FIG. 1) is shown in FIG. 7 (the horizontal axis is time, and the vertical axis is torque). When the position command θ * having the same waveform is input, the motor position command θM * (first embodiment) shown in FIG. Does not fluctuate sharply compared to the motor position command θM * (FIG. 36). This is because the second-order filter of the block 2 in FIG. 5 makes the gain of the frequency characteristic of FIG. 4A particularly higher than ωa lower than that of FIG. 33A shown in the conventional example. to cause.
[0067]
In the conventional example (FIG. 37), the torque command T * output by the speed control unit 113 (FIG. 26) becomes an excessive value at the acceleration fluctuation times A, B, C, and D of the position command θ *, and the limit is set. Was hung As shown in FIG. 7, in the present embodiment, the torque command T * output by the speed control unit 17 (FIG. 1) is too large at the acceleration fluctuation times A, B, C, and D of the position command θ *. It will not be a value and will not be limited. The control method and the control device according to the present embodiment always control the vibration of the electric motor and the control target optimally regardless of the command pattern and the characteristics of the control target.
[0068]
Next, the role of ωf derived in step S3 and the reason for deriving ωf using ωa and the acceleration (second derivative) of the position command θ * as arguments will be described. When the filter unit 9 (FIG. 1) receives the position command θ * indicated by the broken line in FIG. 6, the block 1 in FIG. 5 outputs a signal having the same waveform as the waveform indicated by the solid line in FIG. Block 2 (FIG. 5) inputs a signal having a waveform shown by a solid line in FIG. 36 and outputs a motor position command θM * shown by a solid line in FIG. As shown by the solid line in FIG. 36, the output signal of the block 1 rapidly changes at the acceleration fluctuation points A, B, C, and D of the position command θ *. The smaller the value of ωa and the greater the acceleration of the position command θ *, the greater the change in the output signal of the block 1 at the time points A, B, C, and D. As can be seen from the block diagram of FIG. 5, ωf defines the cutoff frequency of the secondary filter of block 2.
[0069]
In FIG. 6, as the change of the output signal of the block 1 (FIG. 5) at the time points A, B, C, and D at which the acceleration of the position command θ * fluctuates, the parameter automatic setting unit 10 decreases ωf. The cutoff frequency of the secondary filter is reduced, and the change in the motor position command θM * at the time points A, B, C, and D at which the acceleration of the position command θ * fluctuates is reduced. If ωf is not made sufficiently small, the torque command T * sharply increases as shown in FIG. 37 when the acceleration of the position command θ * fluctuates, and a limit can be applied. The control device cannot perform normal control. This is the reason that the automatic parameter setting unit 10 automatically sets ωf as ωa and the acceleration of the position command θ * in step S3 as arguments. The parameter automatic setting unit 10 sets ωf to a smaller value as ωa is smaller and the acceleration of the position command θ * is larger. As described above, the parameter automatic setting unit 10 automatically sets ωf, so that the control method and the control device according to the present embodiment always control the vibration of the electric motor and the control target regardless of the command pattern and the characteristics of the control target. Control with optimal suppression.
[0070]
In FIG. 6, the position command θ * indicated by the broken line finishes changing at the time point D, but the change end time point of the motor position command θM * output from the pre-filter unit 8 is later than the time point D. This is due to the effect of the secondary filter in block 2 (FIG. 5) of the pre-filter unit 8. The delay in the change of the motor position command θM * is not preferable because it causes a delay in the response of the control device (in the conventional example, the torque command T * has an excessive value and is compared with the response delay that occurs when the limit is applied). Then, the control device of the present embodiment has a much faster response.)
In periods other than immediately after the time points A, B, C, and D where the torque command T * is likely to be limited, even if the cutoff frequency of the secondary filter of the block 2 is increased, the torque limit is not applied. Utilizing this, the automatic parameter setting unit 10 changes ωf with time. The parameter automatic setting unit 10 increases ωf especially in a period after immediately after the time point D. Thus, the end point of the change of the motor position command θM * is earlier. The control method and the control device according to the present embodiment realize high responsiveness by the parameter automatic setting unit 10 switching the parameters of the filter unit 9.
[0071]
Next, an appropriate setting value of the attenuation coefficient ζ will be described. As ζ is made smaller than 1, the frequency characteristic of the block 2 in FIG. 5 starts to have a gain peak of 0 dB or more near the frequency ωf. In this case, it is not desirable to set ζ to 1 or less because the vibration of the frequency of the gain peak may appear at the control target position θL. The larger the value of ζ, the longer the end point of the change in the motor position command θM * (see FIG. 6), and the slower the response of the control device. The end point of the change is the end point of the change after the motor position command θM * starts to change. Therefore, it is not desirable to make ζ too large. Therefore, it is desirable to set に to about 1.
[0072]
FIG. 8 is a waveform diagram showing a response of the control device (FIG. 1) of the first embodiment when the position commands shown in FIGS. 31 (a) and 31 (b) are input. The broken line indicates the motor position deviation ΔθM, and the solid line indicates the control target position deviation ΔθL. Compared with FIG. 32 which is a response waveform of the motor position deviation ΔθM and the control target position deviation ΔθL when the pre-filter unit 8 is not provided, the control device according to the first embodiment suppresses the vibration after the end of the position command output period. Have been.
The transfer function of the block 1 in FIG. 5 may be changed to Expression (5) including the attenuation term Δn / ωa · s. By adjusting the attenuation coefficient Δn, the gain of the frequency ωa can be adjusted. By appropriately determining the damping coefficient ζn, the vibration of the motor position deviation ΔθM and the control target position deviation ΔθL is further suppressed.
[0073]
(1 / ωa ² ) ・ S ² + (2ζn / ωa) · s + 1 (5)
[0074]
In the conventional control device without the pre-filter unit 8, the motor position deviation when the vibration of the control target position deviation ΔθL is reduced by setting the position proportional gain Kpp and the speed proportional gain Kvp lower than in the example shown in FIG. FIG. 35 shows the responses of ΔθM and the control target position deviation ΔθL. The response of FIG. 8 is faster than the response of FIG. According to the present invention, vibration can be reduced while maintaining a high-speed response, as in the conventional example. FIG. 7 shows the waveform of the torque command T * at the time of the response shown in FIG. At times A, B, C, and D at which the acceleration of the position command θ * fluctuates, the torque command T * does not increase sharply, and the limit is not limited. The control method and control device of the present embodiment respond appropriately even when the acceleration of the position command θ * fluctuates.
[0075]
Under the conditions of a vibration frequency of 11 Hz and a settling width of ± 125 μm, the settling time in the experiment (from the completion of the output (change) of the position command, the position of the tip of the device (the tip of the control target 3) converges to the settling width centered on the target value. The time required until the time point). The settling time for the control without pre-filter was 725 ms. In the conventional control device having the pre-filter unit 107 (FIG. 29), a significant settling time could not be measured because the torque was saturated and the vibration did not converge for a long time. In the control device of the present invention (FIG. 1), the settling time was 45 ms. According to the present invention, the settling time can be reduced to about 1/16 as compared with the case without the pre-filter.
[0076]
FIG. 38 is a diagram showing a configuration of a mounting machine equipped with the control device of the present invention. 38, the same parts as those in FIG. 1 are denoted by the same reference numerals. In FIG. 38, the mounting machine has servo motors 2a, 2b, 2c. Each servo motor corresponds to the electric motor 2 in FIG. Each servo motor is controlled by a servo amplifier 6a, 6b, 6c, respectively.
[0077]
ADVANTAGE OF THE INVENTION According to the control method and control apparatus of this invention, the vibration of a motor and a control object which generate | occur | produces due to low rigidity of a control object or a connection shaft which connects a motor and a control object can be suppressed. The control method and the control device of the present invention always automatically suppress the vibration of the electric motor and the control target regardless of the command pattern or the characteristics of the control target. It is automatically prevented that the torque command T * becomes an excessive value. By automating all the parameter settings of the pre-filter unit 8 in FIG. 1, the response of the control device is increased, and the operability of the device equipped with the control device is improved. Even if the setting value of ωa is automatically changed even if the vibration frequency ωa changes due to the characteristic fluctuation of the controlled object, the vibration can be constantly reduced regardless of the command pattern or the characteristic of the controlled object.
[0078]
In FIG. 1, the configuration of the command following control unit 12 is the same as that of the present embodiment, even if the configuration is such that control is performed so that the motor position θM follows the motor position command θM *. be able to.
The pre-filter unit 8 in FIG. 1 may be configured inside the position command creating unit 1.
[0079]
In the present embodiment, the position control system has been described. The present invention is not limited to this, and can be applied to a speed control system as shown in FIG. In FIG. 9, blocks denoted by the same reference numerals as in FIG. 1 have the same role as in FIG. The speed command creation unit 20 creates a speed command pattern and outputs a speed command according to the pattern. The speed detecting unit 21 detects the speed of the electric motor 2 and outputs the detected speed as ωM. The servo controller 22 performs digital control. The servo controller 22 fetches the speed command from the speed command creation unit 20 and the motor speed ωM from the speed detection unit 21 at regular intervals, performs arithmetic processing, and controls the current I of the motor 2. The speed command input unit 23 receives the speed command from the speed command creating unit 20, converts the speed command into a unit system suitable for internal calculation of the servo controller 22, and outputs it as a speed command ω *. The pre-filter unit 8 (having the transfer function of FIG. 5) receives the speed command ω * and outputs a motor speed command ωM *. The pre-filter unit 8 extracts a vibration frequency of the control target 3 detected by the vibration detection unit 5, and determines a parameter of a transfer function of the filter based on the vibration frequency. The command follow-up control unit 24 performs control so that the motor speed ωM follows the motor speed command ωM *. A position detection unit may be provided instead of the speed detection unit 21. In this case, the motor speed ωM is calculated by differentiating the position information of the electric motor 2 detected by the position detection unit inside the servo controller 22. The pre-filter unit 8 of FIG. 9 may be arranged inside the speed command creation unit 20.
[0080]
In the speed control device of FIG. 9, it is possible to suppress vibration of the motor and the control target that occur due to low rigidity of the control target or the connection shaft that connects the motor and the control target. The speed control device automatically and appropriately controls the electric motor regardless of the command pattern or the characteristics of the control target. The speed control device automatically prevents the torque command from becoming excessive. The operability of the control device can be improved by automating the parameter setting of the pre-filter unit 8 in FIG.
[0081]
The filter unit 9 in FIG. 1 does not have to have the configuration in FIG. As shown in FIG. 4A, it has a characteristic of lowering the gain of the predetermined frequency ωa (preferably, near the anti-resonance frequency fr × 2π of the control target 3) and a frequency near the predetermined frequency ωa, and a characteristic of suppressing the gain in the high frequency range. Any configuration may be used.
When the control target position θL in FIG. 1 is vibrating at a plurality of vibration frequencies, the filter unit 9 has a characteristic of lowering the gain of the plurality of vibration frequencies and frequencies near them and suppressing the gain in a high frequency range. .
[0082]
In the flowchart of FIG. 2, the state quantity capturing process in step S2 may be performed at any timing from the start to before step S5.
The electric motor is not limited to a particular type. The motor may be a DC motor, a permanent magnet synchronous motor, or an induction motor. The electric motor is not limited to a rotary electric motor, but may be a linear motor.
The command pattern of the position command θ * may be created by the position command input unit 7 inside the servo controller 6 instead of the position command creating unit 1. In this case, the position command input unit 7 outputs the position command θ * at regular intervals based on the created command pattern.
[0083]
<< Embodiment 2 >>
Second Embodiment A control method and a control device of a motor according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 10 is a diagram showing a configuration of a control block in a motor control method according to Embodiment 2 of the present invention. 10 is different from FIG. 1 of the first embodiment in the configuration of the pre-filter unit 8. The pre-filter unit 8 according to the second embodiment includes an equivalent filter unit 11 and a compensation value application unit 30 instead of the filter unit 9. In FIG. 10, blocks with the same reference numerals as those in FIG. 1 play the same role as in the first embodiment.
[0084]
The detailed operation of the control device shown in FIG. 10 will be described. Since the position command creating unit 1 and the position detecting unit 4 are the same as those in the first embodiment, the description is omitted. The servo controller 6 performs digital control. The servo controller 6 controls the current I of the motor 2 by inputting the position command from the position command creating unit 1 and the motor position θM from the position detecting unit 4 at regular intervals and performing arithmetic processing.
FIG. 11 shows a flowchart of a one-cycle calculation process executed by the servo controller 6. The servo controller 6 repeats the arithmetic processing shown in FIG. 11 at a constant arithmetic cycle (for example, 166 μs). The processing of FIG. 11 will be described with reference to FIGS. 11, steps having the same reference numerals as those in FIG. 2 perform the same processing as in the first embodiment. Steps S1 to S3 in FIG. 11 perform the same processing as steps S1 to S3 in FIG.
[0085]
The equivalent filter unit 11 receives the position command θ * and outputs a compensation value Xc (pre-filter processing in step S10). FIG. 12 shows a transfer function of the equivalent filter unit 11 using a Laplace operator s. Actually, the transfer function in FIG. 12 is converted into a digital filter obtained by converting the transfer function by a method such as bilinear conversion, and the equivalent filter unit 11 performs an operation as a digital filter. The digital filter receives the position command θ * output in step S1 and outputs a compensation value Xc. The reason why the configuration of the equivalent filter unit 11 is shown in FIG. 12 will be described later.
[0086]
The position deviation calculator (differentiator) 13 calculates ΔθM (n) = θ * (n) −θM (n) and outputs the motor position deviation ΔθM (n) (position control processing 1 in step S11). The compensation value application unit (adder) 30 outputs a value obtained by adding the output value Xc (n) of step S10 to the output value ΔθM (n) of step S11 (compensation value application processing of step S12). The position control unit 14 outputs a motor speed command ωM * (n) that is a value obtained by multiplying the output value (ΔθM (n) + Xc (n)) of step S12 by the position proportional gain Kpp (the position control process of step S13). 2).
[0087]
The speed deviation calculator (differentiator) 16 calculates a value ΔωM (n) = ωM * (n) obtained by subtracting the motor position θM (n) fetched in step S2 from the output value of step S13 (output value of the position control unit 14). ) -ΘM (n) is output (speed control processing 1 in step S14). The speed control unit 17 performs the proportional integral operation of Expressions (3) and (4) using the output value ΔωM (n) of Step S14, and outputs a torque command T * (n) (speed control of Step S15). Processing 2). The current control unit 18 controls the current I corresponding to the output value T * (n) in step S15 to flow through the electric motor 2 (current control processing in step S16). The above is the calculation process for one cycle of the internal calculation of the servo controller 6 shown in the flowchart of FIG.
[0088]
The reason why the configuration of the equivalent filter unit 11 is shown in FIG. 12 will be described. The transfer function of the filter unit 9 according to the first embodiment of FIG. 1 is represented by Expression (6) (FIG. 5).
｛(1 / ωa ² ) ・ S ² +1｝ / ｛(1 / ωf ² ) ・ S ² + 2ζ / ωf · s + 1｝ (6)
[0089]
When Expression (6) is converted, Expression (7) is obtained.
1 + [｛(1 / ωa ² −1 / ωf ² ) ・ S ² − (2ζ / ωf) · s｝ / ｛(1 / ωf ² ) ・ S ² + (2ζ / ωf) · s + 1｝] (7)
[0090]
Based on this, FIG. 13 is equivalently converted to FIG. Block 3 in FIG. 13 is equivalent to FIG. Therefore, the configuration of the first embodiment shown in FIG. 1 is equivalent to the configuration of the present embodiment shown in FIG. The second embodiment is equivalent to the first embodiment and has the same effect.
[0091]
In the second embodiment, the convergence value of θM does not deviate from the convergence value of the position command θ *, as compared with the first embodiment. In the second embodiment, the compensation value Xc of the pre-filter unit 8 is added to the motor position deviation ΔθM by the compensation value application unit 30 at the subsequent stage of the position deviation calculation unit 13. The position deviation calculating unit 13 calculates ΔθM = θ * −θM. The command following control unit 12 controls the motor position deviation ΔθM to be zero. Since the control device controls the motor position θM using the position command θ * as a target value as it is, the convergence value (stop position) of the position command θ * matches the convergence value of the motor position θM. Therefore, in the present embodiment, the convergence value of θM does not deviate from the convergence value of position command θ *.
[0092]
In the first embodiment shown in FIG. 1, the position deviation calculator (subtractor) 13 performs the calculation of ΔθM = θM * −θM. The command following control unit 12 controls the motor position deviation ΔθM to be zero. The convergence value (stop position) of the motor position command θM * may be different from the convergence value of the position command θ * due to a digit drop or the like generated by the calculation of the filter unit 9 in FIG.
Since the convergence value between the position command θ * and the motor position θM is different, the convergence value of θM deviates from the convergence value of the position command θ *. In the first embodiment, in order to always make the convergence values of the position command θ * and the motor position command θM * coincide with each other, it is necessary to perform a deviation compensation process. In the second embodiment, the shift compensation processing is not required.
[0093]
As described above, in the second embodiment, the same effect as in the first embodiment can be obtained. The control method and the control device according to the second embodiment suppress the vibration of the electric motor 2 and the control target 3 caused by the low rigidity of the control target or the connection shaft that connects the electric motor and the control target. The control method and the control device according to the second embodiment always automatically suppress the vibration of the electric motor and the control target regardless of the command pattern or the characteristics of the control target 3. It is automatically prevented that the torque command T * becomes an excessive value. The operability of the control device is improved by automatically setting all the parameters of the equivalent filter unit 11 in FIG. The control method and the control device according to the second embodiment always reduce the vibration by adaptively changing the value of the parameter of the filter even if the vibration frequency changes due to the characteristic fluctuation of the control target.
In the present embodiment, the filter 9 of FIG. 1 is equivalently changed to have a feedforward configuration, thereby eliminating the shift due to the digit loss of the calculation. Since there is no need to perform displacement compensation, the calculation time by software can be reduced, and the labor required for software creation can be reduced. Alternatively, a circuit for compensating for the deviation can be eliminated, the development effort of the LSI can be reduced, and the chip area of the LSI can be reduced.
[0094]
The compensation value application section 30 in FIG. 10 may be applied anywhere on the main signal path as long as the compensation value application section 30 is provided at a stage subsequent to the position deviation calculation section 13. For example, FIG. 10 may be equivalently converted to FIG. 14 or FIG. 14 and 15 have the same effects as in FIG. The flowchart (control method) of the control device in FIG. 14 calculates the compensation value Xc by performing the processing of the equivalent filter unit 11 and the position control unit 14 in step S10 in FIG. ) Is performed between step S13 and step S14. The flowchart (control method) of the control device in FIG. 15 calculates the compensation value Xc by performing the processing of the equivalent filter unit 11, the position control unit 14, and the speed control unit 17 in step S10 in FIG. (Compensation value application processing) is executed between step S15 and step S16.
[0095]
In the present embodiment, the configuration of FIG. 5 is equivalently converted to FIG. 13 by equation (7). In the present invention, the transfer function is not limited to the transfer function shown in FIG. 5, but may be an arbitrary transfer function having a characteristic of lowering the gain of a predetermined frequency and a frequency near the predetermined frequency as shown in FIG. Functions can be used. Similarly to the equation (7), such a transfer function can be equivalently converted into a form of 1 + Ge (s), and Ge (s) can be formed into a feedforward configuration. Thereby, the same effect as in the present embodiment can be obtained.
The pre-filter parameter automatic setting process in step S3 in FIG. 11 may be executed at any time as long as the process is completed before the pre-filter process in step S10. The pre-filter process in step S10 may be executed at any time as long as the process is completed before the compensation value application process in step S12.
[0096]
In FIG. 10, the configuration of the command follow-up control unit 12 can obtain the same effect as that of the present embodiment even if the configuration is such that the motor position θM follows the position command θ *. Can be.
The pre-filter unit 8 in FIG. 10 may be arranged inside the position command creating unit 1.
In the present embodiment, the position control system has been described, but the present invention can be applied to the speed control system as described in the first embodiment. In this case, the pre-filter unit may be arranged inside a speed command creating unit that creates a speed command pattern and outputs a speed command.
In the case where the control target position θL in FIG. 10 is vibrating at a plurality of vibration frequencies, assuming that the transfer function of the equivalent filter unit 11 is Ge (s), the transfer function 1 + Ge (s) becomes the plurality of vibration frequencies and their The gain of a nearby frequency is reduced, and the gain of a high frequency band is suppressed.
[0097]
In the flowchart of FIG. 11, the process of step S2 may be performed at any timing from the start to before step S11.
The electric motor is not limited to a particular type. The motor may be a DC motor, a permanent magnet synchronous motor, or an induction motor. The electric motor is not limited to a rotary electric motor, but may be a linear motor.
The command pattern of the position command θ * may be created by the position command input unit 7 inside the servo controller 6 instead of the position command creating unit 1. In this case, the position command input unit 7 outputs the position command θ * at regular intervals based on the created command pattern.
[0098]
<< Embodiment 3 >>
Third Embodiment A control method and a control device for a motor according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 16 is a block diagram showing a configuration of a motor control device according to Embodiment 3 of the present invention. FIG. 16 differs from FIG. 1 of the first embodiment in the configuration of the pre-filter unit 8. The pre-filter unit 8 according to the third embodiment includes a command estimating unit 40, an equivalent internal filter unit 41, and a compensation value applying unit (adder) 42 instead of the filter unit 9. Further, the position command input unit 7, the position deviation calculation unit 13, and the position control unit 14 are configured outside the servo controller 43. These blocks arranged outside the servo controller 43 are composed of, for example, existing LSIs or existing software whose processing contents are not disclosed. The processing in these blocks cannot be changed, and the output signals of these blocks cannot be read only by specific signals (used by the control method and control device of the present invention). These points are different from FIG. In FIG. 16, blocks denoted by the same reference numerals as in FIG. 1 play the same role as in the first embodiment.
[0099]
The detailed operation of the control device in FIG. 16 will be described. Since the position command creating unit 1 and the position detecting unit 4 are the same as those in the first embodiment, the description is omitted. The position command input unit 7, the position deviation calculation unit 13, and the position control unit 14 have the same roles as in the first embodiment, and thus description thereof is omitted, but unlike the first embodiment, they are configured outside the servo controller 43. I have. The operation of these blocks cannot be changed. The servo controller 43 inputs only the speed command ω * output from the position control unit 14. The servo controller 43 cannot input information other than the speed command ω * (for example, the position command θ *) from an upper level.
The servo controller 43 performs digital control. The servo controller 43 takes in the speed command ω * from the position control unit 14 and the motor position θM from the position detection unit 4 at regular intervals, performs arithmetic processing, and controls the current I of the motor 2. FIG. 17 shows a flowchart of a one-cycle calculation process executed by the servo controller 43. The servo controller 43 repeats the arithmetic processing shown in FIG. 17 at a constant arithmetic cycle (for example, 166 μs). The processing of FIG. 17 will be described with reference to FIGS. In the steps denoted by the same reference numerals as those in FIG. 2, the same processes as those in the first embodiment are performed.
[0100]
The servo controller 43 takes in the speed command ω * output from the position control unit 14 and sets it as ω * (n) (command fetch process in step S20). Steps S2 and S3 are the same as those in the first embodiment, and a description thereof will be omitted. The command estimating unit 40, the equivalent internal filter unit 41, and the compensation value applying unit 42 perform calculations to apply the compensation value Xc to the speed command ω * (pre-filtering in step S21).
The command estimating unit 40 estimates and calculates an estimated position command θe * from the speed command ω * and the motor position θM using the following equation (8).
θe (n) = ω * (n) / Kpp + θM (n) (8)
[0101]
FIG. 18 shows a transfer function of an internal block of the equivalent internal filter unit 41. The configuration is the same as that of the block 3 in FIG. 13, that is, the configuration of the second term when the pre-filter 9 in FIG. 1 is equivalently converted using the equation (7), multiplied by the proportional gain Kpp of the position control unit. . Actually, the transfer function of FIG. 18 is converted into a digital filter converted by a method such as bilinear conversion, and the equivalent internal filter unit 41 performs an operation as a digital filter. The digital filter receives the estimated position command θe * calculated by equation (8) and outputs a compensation value Xc. FIG. 18 operates on the same principle as that of the second embodiment (FIG. 14) except that the input is the position command θ * or the estimated position command θe *. With the configuration in FIG. 18, the same vibration suppression effect as in the second embodiment can be obtained. The compensation value application unit (adder) 42 adds the speed command ω * and the compensation value Xc output from the equivalent internal filter unit 41, and outputs the result as ωM *. The reason why the configuration of the equivalent internal filter unit 41 is shown in FIG. 18 will be described later.
Steps S6 and S7 are the same as those in the first embodiment, and a description thereof will not be repeated. The above is the one-cycle calculation process of the servo controller 43 shown in the flowchart of FIG.
[0102]
The reason why the configuration of the equivalent internal filter unit 41 is shown in FIG. 18 will be described. The configuration of the first embodiment shown in FIG. 1 is shown in a block diagram using a Laplace operator in FIG. F in FIG. 19 is Expression (6) representing the transfer function of the filter unit 9. G (s) is a transfer function of the electric motor 102 in FIG. 29, and is a transfer function from the torque command T * to the electric motor position θM. s is a Laplace operator. FIG. 20 is a block diagram obtained by equivalently converting FIG. In FIG. 20, F11, F21, F31, F32, and F33 are equations (9) to (13), respectively.
[0103]
F11 (s) = Kpp · ｛(1 / ωf ² −1 / ωa ² ) ・ S ² + (2ζ / ωf) · s｝ / ｛(1 / ωa ² ) ・ S ² +1｝ (9)
F21 (s) = Kpp · ｛(1 / ωf ² −1 / ωa ² ) ・ S ² + (2ζ / ωf) · s｝ / ｛(1 / ωf ² ) ・ S ² + (2ζ / ωf) · s + 1｝ (10)
F31 (s) = 1 / Kpp (11)
F32 (s) = 1 (12)
F33 (s) = Kpp ｛(1 / ωa ² −1 / ωf ² ) ・ S ² − (2ζ / ωf) · s｝ / ｛(1 / ωf ² ) ・ S ² + (2ζ / ωf) · s + 1｝ (13)
[0104]
In FIG. 20A, since the block F11 has a gain peak in the frequency characteristic, the control system is likely to be unstable when mounted (for example, the output signal of the block F11 is limited, and the control of the control device becomes difficult). It becomes unstable.) In FIG. 20B, the block F (s) enters the position control loop in series. Since F (s) removes the high frequency feedback information, the responsiveness of the control device decreases.
FIG. 20C shows the configuration of the present embodiment. In the configuration of FIG. 20C, since there is no block having a gain peak as in FIG. 20A, the stability of the control system at the time of mounting can be ensured. In addition, since the compensation amount Xc for vibration suppression is calculated independently of the feedback information, the responsiveness of the position control loop does not decrease as shown in FIG. Even when the degree of freedom in changing the configuration of the command creation unit and the control block is limited as in the third embodiment (for example, even when the internal block of an existing LSI is used as it is and the specification cannot be changed for that block). 20 (c) in which the pre-filter 8 of FIG. 1 is equivalently transformed, a vibration suppression effect can be obtained without impairing the stability and response of the control system.
[0105]
As described above, according to the present embodiment, it is possible to suppress vibration of the motor 2 and the control target 3 caused by low rigidity of the control target (load) or the connection shaft connecting the motor and the control target. it can. The control method and the control device according to the second embodiment always automatically suppress the vibration of the electric motor and the control target regardless of the command pattern or the characteristics of the control target 3. It is automatically prevented that the torque command T * becomes an excessive value. The operability of the control device is improved by automatically setting all the parameters of the pre-filter unit 8 in FIG. The control method and the control device according to the third embodiment always reduce the vibration by adaptively changing the value of the parameter of the filter even if the vibration frequency changes due to the characteristic fluctuation of the control target.
In the present embodiment, the filter 9 of FIG. 1 is equivalently changed to be of an internal configuration type, thereby eliminating the shift due to the digit loss of the calculation. Since there is no need to perform displacement compensation, the calculation time by software can be reduced, and the labor required for software creation can be reduced. Alternatively, a circuit for compensating for the deviation can be eliminated, the development effort of the LSI can be reduced, and the chip area of the LSI can be reduced.
According to the present invention, the vibration suppression effect can be obtained without impairing the stability and responsiveness of the control system even when the degree of freedom in changing the configuration of the command creation unit or the control block is limited.
[0106]
In FIG. 20C, the estimation command θe * may be calculated from the motor speed ωM as in FIG. 21A. As long as the compensation amount Xc is calculated independently of the stability and responsiveness of the feedback loop itself, the equivalent conversion shown in FIG. 20C may be arbitrarily performed. For example, FIG. 20 (c) may be equivalently converted as shown in FIGS. 21 (b) and 21 (c). In this case, F34, F35, and F36 are represented by equations (14) to (16), respectively.
[0107]
F34 (s) = 1 / Kpp · s (14)
F35 (s) = 1 (15)
F36 (s) = Kpp · ｛(1 / ωa ² −1 / ωf ² ) · S-2ζ / ωf｝ / ｛(1 / ωf ² ) ・ S ² + (2ζ / ωf) · s + 1｝ (16)
[0108]
If the configurations in FIGS. 20C and 21 do not change, the equations of F31, F32, F33 and F34, F35, F36 may be equivalently converted to other equations. For example, F34, F35, and F36 may be equivalently converted into equations (17) to (19).
[0109]
F34 (s) = s (17)
F35 (s) = Kpp (18)
F36 (s) = ｛(1 / ωa ² −1 / ωf ² ) · S-2ζ / ωf｝ / ｛(1 / ωf ² ) ・ S ² + (2ζ / ωf) · s + 1｝ (19)
[0110]
The configuration of the filter unit 9 in FIG. 1 before the equivalent conversion to FIGS. 20 and 21 is not limited to the configuration of Expression (6). An arbitrary configuration having a characteristic of lowering the gain of the predetermined frequency ωa and frequencies near the predetermined frequency ωa as shown in FIG.
When the control target position θL in FIG. 16 oscillates at a plurality of vibration frequencies, the filter unit 9 has a characteristic of reducing the gain of the plurality of vibration frequencies and the frequencies in the vicinity thereof and suppressing the gain in the high frequency range. .
The electric motor is not limited to a particular type. The motor may be a DC motor, a permanent magnet synchronous motor, or an induction motor. The electric motor is not limited to a rotary electric motor, but may be a linear motor.
[0111]
<< Embodiment 4 >>
Fourth Embodiment A control method and a control device for a motor according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 22 is a block diagram showing a configuration of a motor control device according to Embodiment 4 of the present invention.
The point that this embodiment is different from the first embodiment of FIG. 1 will be described. In the control device of the present embodiment of FIG. 22, the method by which parameter automatic setting unit 10 calculates vibration frequency ωa of control target (load) 3 is different from that of the first embodiment (FIG. 1). The control device of the present embodiment does not include the vibration detection unit 5 (FIG. 1). The parameter automatic setting unit 10 obtains ωa based on the motor position θM. Example 4 is different from Example 1 in this point. The control device of the present embodiment is less expensive than the first embodiment because the vibration detection unit 5 of FIG. 1 is not required.
[0112]
In the present embodiment, it is necessary that a vibration component having the same frequency as the vibration at the control target position θL can be detected at the motor position θM. For example, the inertia of the control target 3 is very small as compared with the inertia of the motor 2, and a vibration component having the same frequency as the vibration of the control target position θL is unlikely to appear at the motor position θM. If it cannot be detected, the configuration of the fourth embodiment cannot be applied. This is because the vibration frequency ωa of the control target position θL cannot be calculated from the motor position θM. In this respect, the fourth embodiment is different from the first embodiment in that the scope of application is restricted.
In the fourth embodiment, it is assumed that a vibration component having the same frequency as the vibration of the control target position θL can be detected at the motor position θM.
[0113]
The detailed operation of the control device in FIG. 22 will be described. Since the position command creating unit 1 and the position detecting unit 4 are the same as those in the first embodiment, the description is omitted. The servo controller 6 performs digital control. The servo controller 6 inputs the position command from the position command creating unit 1 and the motor position θM from the position detecting unit 4 at regular intervals, performs arithmetic processing, and controls the current I of the motor 2. FIG. 23 shows a flowchart of a one-cycle calculation process executed by the servo controller 6. The servo controller 6 repeats the arithmetic processing shown in FIG. 23 at a constant arithmetic cycle (for example, 166 μs). The processing in FIG. 23 will be described with reference to FIG. In FIG. 23, the processing other than step S22 is the same as that of the first embodiment, and thus the description is omitted.
[0114]
In the pre-filter parameter automatic setting process of step S22, the parameter automatic setting unit 10 calculates the vibration frequency ωa of the control target position θL based on the motor position θM detected by the position detection unit 4. The parameter automatic setting unit 10 measures the zero-crossing time interval of the motor position deviation ΔθM after the end of the change of the position command θ *, for example, and calculates the vibration frequency of the motor position θM. Instead of the motor position deviation Δθ, ωa may be calculated using a motor speed deviation ΔωM or a state quantity inside the command following control unit 12 such as the torque command T *. Since the vibration frequency of the motor position θM and the vibration frequency of the control target position θL are theoretically the same, the calculated vibration frequency of the motor position θM is set as the vibration frequency fr of the control target position θL. Let ωa = 2π · fr.
[0115]
The parameter automatic setting unit 10 determines ωf based on the calculated ωa. ωf determines the cutoff frequency of the filter unit 9 (FIG. 22) having the characteristic of lowering the high-frequency gain. In determining ωf, for example, a table or a calculation formula based on a graph that determines the relationship between ωa and ωf shown in FIG. 3 is used. ωf may be determined using a two-dimensional table in which ωa and the acceleration of the position command θ * are used as arguments. The damping coefficient ζ is fixed to 1. The role of ωa, the role of ωf, the reason for determining ωf using ωa and the acceleration of the position command θ * as arguments, and a detailed description of the appropriate set value of ζ have been given in the first embodiment, and will not be repeated here. .
[0116]
As described above, according to the present embodiment, the vibration of the motor 2 and the control target 3 caused by the low rigidity of the control target (load) itself or the connection shaft connecting the motor and the control target is suppressed. Can be. The control method and the control device according to the fourth embodiment always automatically suppress the vibration of the electric motor and the control target regardless of the command pattern or the characteristics of the control target 3. It is automatically prevented that the torque command T * becomes an excessive value. By automatically setting all the parameters of the pre-filter unit 8, the operability of the control device is improved. The control method and the control apparatus according to the fourth embodiment always reduce the vibration by adaptively changing the value of the parameter of the filter even if the vibration frequency changes due to the characteristic fluctuation of the control target.
The control method and the control device of the present embodiment are less expensive than the first embodiment because the vibration detection unit 5 of FIG. 1 of the first embodiment is unnecessary.
[0117]
In FIG. 22, the configuration of the command follow-up control unit 12 may be another configuration as long as the control is performed so that the motor position θM follows the motor position command θM *. With such a configuration, the same effect as in the present embodiment can be obtained.
In the present embodiment, the position control system has been described, but the present invention is also applicable to a speed control system as described in the first embodiment. In this case, the pre-filter unit 8 may be arranged inside a speed command creating unit that creates a speed command pattern and outputs a speed command.
The configuration of the filter unit 9 in FIG. 22 is arbitrary as long as it has a characteristic of lowering the gain of the predetermined frequency ωa and the frequency in the vicinity thereof as shown in FIG. It is.
[0118]
The pre-filter unit 8 in FIG. 22 may be arranged inside the position command creating unit 1.
When the control target position θL in FIG. 22 is vibrating at a plurality of vibration frequencies, the filter unit 9 has a characteristic of reducing the gain of the plurality of vibration frequencies and the frequencies in the vicinity thereof and suppressing the gain in the high frequency range. .
In the flowchart of FIG. 23, the process of step S2 may be performed before step S1.
The electric motor is not limited to a particular type. The motor may be a DC motor, a permanent magnet synchronous motor, or an induction motor. The electric motor is not limited to a rotary electric motor, but may be a linear motor.
The command pattern of the position command θ * may be created by the position command input unit 7 inside the servo controller 6 instead of the position command creating unit 1. In this case, the position command input unit 7 outputs the position command θ * at regular intervals based on the created command pattern.
[0119]
<< Embodiment 5 >>
Fifth Embodiment A motor control method and a control device according to a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 24 is a block diagram illustrating a configuration of a motor control device according to Embodiment 5 of the present invention.
The point that this embodiment is different from the first embodiment of FIG. 1 will be described. In the control device of the present embodiment shown in FIG. 24, the method by which parameter automatic setting unit 10 calculates vibration frequency ωa of control target (load) 3 is different from that of the first embodiment (FIG. 1). The control device of the present embodiment does not include the vibration detection unit 5 (FIG. 1). In the present embodiment, the parameter automatic setting unit 10 obtains the vibration frequency ωa of the control target position θL from the state quantity used for the calculation inside the servo controller 6 using the mathematical model of the electric motor 2 and the control target 3.
[0120]
The detailed operation of the control device in FIG. 24 will be described. Since the position command creating unit 1 and the position detecting unit 4 are the same as those in the first embodiment, the description is omitted. The servo controller 6 performs digital control. The servo controller 6 inputs the position command from the position command creating unit 1 and the motor position θM from the position detecting unit 4 at regular intervals, performs arithmetic processing, and controls the current I of the motor 2. FIG. 25 shows a flowchart of a one-cycle calculation process executed by the servo controller 6. The servo controller 6 repeats the calculation processing shown in FIG. 25 at a constant calculation cycle (for example, 166 μs). The processing in FIG. 25 will be described with reference to FIG. Processing other than steps S25, S26, and S27 is the same as that of the first embodiment, and a description thereof will be omitted.
In step S25, the automatic parameter setting unit 10 determines whether the electric motor 2 is accelerating. If the vehicle is accelerating, the process proceeds to the inertia estimating process of step S26. If the vehicle is not accelerating, the process proceeds to a pre-filter parameter automatic setting process of step S27. In the inertia estimation process of step S26, the parameter automatic setting unit 10 estimates the inertia JL of the control target 3 from the electric motor position θM, which is a state quantity in the servo controller 6, and the torque command T *. The parameter automatic setting unit 10 performs calculations of the equations (20) to (24).
[0121]
ωMc (n) = θM (n) −θM (n−1) (20)
aM (n) = Ku (ωMc (n) −ωMc (n−1)) (21)
aMf (n) = aMf (n−1) + Kf · (aM (n) −aMf (n−1)) (22)
J (n) = aMf (n) / T * (n-1) (23)
JL (n) = J (n) -JM (24)
[0122]
ωMc is a calculated speed value, aM is a calculated acceleration value, aMf is a calculated acceleration value after filtering, Kf is a filter constant, Ku is a unit conversion coefficient, J is an inertia of the electric motor 2 and the controlled object 3 combined, and a constant JM is an electric motor. 2 inertia. In the pre-filter parameter automatic setting process in step S27, the parameter automatic setting unit 10 calculates the vibration frequency fr of the control target 3. Let ωa = 2π · fr. Equation (25) is used for the calculation.
[0123]
ωa (n) = (Ks / JL (n)) ^1/2 (25)
[0124]
The constant Ks is a spring constant. The reason why equation (25) is used to calculate ωa will be described later. The frequency ωf is determined based on the calculated ωa. The determination of ωf uses, for example, a table or a calculation formula based on a graph that determines the relationship between ωa and ωf shown in FIG. ωf may be determined using a two-dimensional table in which ωa and the acceleration of the position command θ * are used as arguments. The damping coefficient ζ is fixed to 1. The role of ωa, the role of ωf, the reason for determining ωf using ωa and the acceleration of the position command θ * as arguments, and a detailed description of the appropriate set value of ζ have been given in the first embodiment. Omitted.
[0125]
The reason why equation (25) is used to calculate the vibration frequency ωa of the control target 3 will be described. As described in the conventional example, when the electric motor 2 and the control target 3 are mathematically modeled with the model of FIG. 27, a block diagram thereof is shown in FIG. JM is the inertia of the motor 2, JL is the inertia of the control target 3, and Ks is the spring constant of the connecting shaft between the motor 2 and the control target 3. The inertia of the connecting shaft is ignored because it is very small compared to JM and JL. FIG. 30A shows the frequency characteristic from the torque command T * to the electric motor position θM. As described in the description of the conventional example, the vibration frequency ωa (= 2π · fr) of the control target 3 is near the anti-resonance frequency in FIG. The vibration frequency ωa is derived by the following equation (26) from the block diagram of FIG.
[0126]
ωa = (Ks / JL) ^1/2 (26)
[0127]
The calculation of ωa in equation (25) is based on equation (26).
As described above, according to the present embodiment, the vibration of the motor 2 and the control target 3 caused by the low rigidity of the control target (load) itself or the connection shaft connecting the motor and the control target is suppressed. Can be. The control method and the control device according to the fifth embodiment always automatically suppress the vibration of the electric motor and the control target regardless of the command pattern or the characteristics of the control target 3. It is automatically prevented that the torque command T * becomes an excessive value. By automatically setting all the parameters of the pre-filter unit 8, the operability of the control device is improved. The control method and the control device according to the fifth embodiment always reduce the vibration by adaptively changing the value of the parameter of the filter even if the vibration frequency changes due to the characteristic fluctuation of the control target.
The control method and the control device of the present embodiment are less expensive than the first embodiment because the vibration detection unit 5 of FIG. 1 of the first embodiment is unnecessary.
[0128]
In steps S25, S26, and S27 in FIG. 25, the vibration frequency ωa of the control target 3 is calculated. The estimation method of ωa is not limited to Expressions (20) to (25). Any method can be used as long as ωa is obtained based on the simplified mathematical model of the electric motor 2 and the control target 3 using the state quantity inside the servo controller 6.
In FIG. 24, the configuration of the command following control unit 12 may be another configuration as long as the control is performed such that the motor position θM follows the motor position command θM *. With such a configuration, the same effect as in the present embodiment can be obtained.
[0129]
Although the position control system has been described in the present embodiment, the present invention can be applied to a speed control system as described in the first embodiment. In this case, the pre-filter unit may be arranged inside a speed command creating unit that creates a speed command pattern and outputs a speed command.
The configuration of the filter unit 9 in FIG. 24 is arbitrary as long as it has a characteristic of lowering the gain of the predetermined frequency ωa and the frequency in the vicinity thereof as shown in FIG. is there.
The pre-filter unit 8 in FIG. 24 may be arranged inside the position command creating unit 1.
When the control target position θL in FIG. 24 oscillates at a plurality of vibration frequencies, the filter unit 9 has a characteristic of reducing the gain of the plurality of vibration frequencies and the frequencies in the vicinity thereof and suppressing the gain in the high frequency range. .
[0130]
In the flowchart of FIG. 25, the process of step S2 may be performed before step S1.
The electric motor is not limited to a particular type. The motor may be a DC motor, a permanent magnet synchronous motor, or an induction motor. The electric motor is not limited to a rotary electric motor, but may be a linear motor.
The command pattern of the position command θ * may be created by the position command input unit 7 inside the servo controller 6 instead of the position command creating unit 1. In this case, the position command input unit 7 outputs the position command θ * at regular intervals based on the created command pattern.
[0131]
【The invention's effect】
According to the present invention, since the pre-filter has both the characteristic of lowering the gain of the predetermined frequency ωa and the frequency near the predetermined frequency ωa and the characteristic of suppressing the high-frequency gain, the control target (load) itself or the motor and the motor can be controlled. It is possible to obtain an effect of suppressing vibration of the motor and the control target that occur due to low rigidity of the connection shaft connecting the target and the control shaft.
ADVANTAGE OF THE INVENTION According to this invention, the vibration of an electric motor and a controlled object can always be suppressed regardless of the command pattern or the characteristic of a controlled object. An advantageous effect is obtained that a control method and a control device for an electric motor that automatically prevents the torque command T * from becoming an excessive value can be realized.
[0132]
According to the present invention, a transfer function of a filter having both a characteristic of lowering a gain of a predetermined frequency ωa and a frequency in the vicinity thereof and a characteristic of suppressing a gain in a high frequency band is equivalently converted into a feedforward type prefilter. Accordingly, an advantageous effect that a motor control method and a control device can be realized in which a convergence value error of a motor position due to a digit cancellation in a calculation does not occur, a correction of a calculation error is unnecessary, and a high positioning accuracy is realized. can get.
[0133]
According to the present invention, an estimation command is generated by estimating a command based on a state quantity in a feedback loop, and has both a characteristic of lowering a gain of a predetermined frequency ωa and a frequency in the vicinity thereof and a characteristic of suppressing a high-frequency gain. The transfer function of the filter is equivalently converted to the sum of a constant term and a feedforward compensation term, an estimation command is applied to the feedforward compensation term to determine an internal compensation amount, and the internal compensation amount is input into a feedback loop. By configuring the internal configuration type pre-filter, even when the degree of freedom in changing the configuration of the command creation unit and the control block is limited, the motor that suppresses vibration without impairing the stability and responsiveness of the control system An advantageous effect that a control method and a control device can be realized is obtained.
[0134]
According to the present invention, by making the gain of the predetermined frequency ωa variable, there is obtained an advantageous effect that a control method and a control device for a motor that further improves the vibration suppression effect can be realized.
According to the present invention, the characteristics of the pre-filter, the feed-forward type pre-filter, or the internal configuration type pre-filter that suppresses the gain in the high frequency range depend on the period in which the torque command T * is not likely to be excessively large. By changing them, there is obtained an advantageous effect that it is possible to realize a control method and a control device for a motor that reduce a delay in response due to a characteristic of suppressing a high-frequency gain.
[0135]
According to the present invention, the pre-filter unit, the feed-forward type pre-filter or the internal configuration type pre-filter automatically determines the characteristic for suppressing the high-frequency gain based on at least the predetermined frequency ωa. An advantageous effect is obtained that a control method and a control device for an electric motor with good responsiveness can be realized.
According to the present invention, the pre-filter unit, the feed-forward type pre-filter or the internal configuration type pre-filter automatically sets the predetermined frequency ωa, so that even if the vibration frequency changes due to the characteristic fluctuation of the control target, the pre-filter unit is stable. Thus, an advantageous effect of being able to realize a control method and a control device for a motor that constantly reduces vibration can be achieved.
[0136]
The present invention detects a vibration of a control target and determines a predetermined frequency ωa based on the vibration frequency. As a result, an advantageous effect is obtained in that an optimal response is automatically performed, and a control method and a control device for a motor having high responsiveness can be realized.
According to the present invention, at the time of automatic setting of the vibration frequency, the predetermined frequency ωa is determined based on the vibration frequency of the electric motor, so that an inexpensive electric motor control method and control device can be performed without using a vibration detection unit to be controlled. Is obtained.
[0137]
According to the present invention, at the time of vibration frequency automatic setting, by estimating the mathematical model of the electric motor and the control target, and determining the predetermined frequency ωa based on the mathematical model, without using the vibration detection unit of the control target, An advantageous effect is obtained that an inexpensive motor control method and control device can be realized.
According to the present invention, the pre-filter reduces the gain of the frequency ωa near the anti-resonance frequency of the system from the torque output by the motor to the motor position and the frequency near the anti-resonance frequency, and suppresses the high-frequency gain. By having both of the characteristics and the characteristics, it is possible to suppress the vibration of the control target and realize a control method and a control device having high responsiveness.
[0138]
The control method and the control device for the electric motor according to the present invention have a low mechanical rigidity, such as a wire bonder, a die bonder, a mounting machine, a printing machine, a multi-axis robot, or a machine tool, when a device equipped with the motor is to be controlled. Therefore, the present invention can be applied to any device in which vibration is easily generated. Thereby, the above effects can be obtained.
[Brief description of the drawings]
FIG.
FIG. 1 is a control block diagram showing a configuration of a motor control method according to a first embodiment of the present invention.
FIG. 2
Flowchart in Embodiment 1 according to the present invention
FIG. 3
A graph showing a relationship between an argument and a set value according to the first embodiment of the present invention.
FIG. 4
(A) is a frequency characteristic diagram of the filter unit 9 according to the first embodiment of the present invention, (
b) is a frequency characteristic diagram from the position command θ * to the control target position θL.
FIG. 5
Configuration diagram of filter section 9 in Embodiment 1 according to the present invention
FIG. 6
Wave of position command θ * and electric motor position command θM * in Embodiment 1 according to the present invention
Shape
FIG. 7
Waveform diagram of torque command T * in Embodiment 1 according to the present invention
FIG. 8
Motor position deviation ΔθM and control target position deviation according to Embodiment 1 of the present invention
Waveform diagram of ΔθL
FIG. 9
When the pre-filter unit 8 according to the first embodiment of the present invention is applied to a speed control system
Block Diagram
FIG. 10
FIG. 6 is a control block diagram showing a configuration of a motor control method according to a second embodiment of the present invention.
FIG. 11
Flowchart in Embodiment 2 according to the present invention
FIG.
Configuration diagram of equivalent filter section 11 in Embodiment 2 according to the present invention
FIG. 13
FIG. 2 is a configuration diagram showing equivalent conversion of the filter unit 9 according to the first embodiment of the present invention.
FIG. 14
Configuration equivalent to FIG. 10 in Embodiment 2 according to the present invention
FIG.
Configuration equivalent to FIG. 10 in Embodiment 2 according to the present invention
FIG.
3 is a control block diagram showing a configuration of a control method for a motor according to a third embodiment of the present invention.
FIG.
Flowchart in Embodiment 3 according to the present invention
FIG.
Configuration diagram of equivalent internal filter section 41 in Embodiment 3 according to the present invention
FIG.
The configuration of FIG. 1 according to the first embodiment of the present invention is represented using a Laplace operator.
Block diagram
FIG.
Configuration diagram equivalent to FIG. 19 in Embodiment 3 according to the present invention
FIG. 21 is a configuration diagram equivalent to FIG. 20C in the third embodiment of the present invention.
FIG. 22 is a control block diagram illustrating a configuration of a motor control method according to a fourth embodiment of the present invention.
FIG. 23 is a flowchart according to the fourth embodiment of the present invention.
FIG. 24 is a control block diagram illustrating a configuration of a control method for a motor according to a fifth embodiment of the present invention.
FIG. 25 is a flowchart according to the fifth embodiment of the present invention.
FIG. 26 is a control block diagram of a conventional electric motor control method.
FIG. 27 is a model diagram of a low-rigidity device.
FIG. 28 is a block diagram in which a low-rigidity device is mathematically modeled.
FIG. 29 is a control block diagram of a conventional motor control method.
FIG. 30 (a) shows a frequency characteristic diagram of a transfer function from a torque command T * to a motor position θM, and FIG. 30 (b) shows a transfer from a motor position command θM * to a motor position θM according to a conventional motor control method. (C) is a frequency characteristic diagram of a transfer function from the motor position θM to the control target position θL, and (d) is a frequency characteristic diagram of a transfer function from the motor position command θM * to the control target position θL.
31 (a) is a command pattern diagram of a position command θ *, and FIG. 31 (b) is a differential waveform diagram of the position command θ * in the conventional motor control method.
FIG. 32 is a waveform diagram of the motor position deviation ΔθM and the control target position deviation ΔθL in the case where the pre-filter unit 107 is not provided in the conventional motor control method.
33A is a frequency characteristic diagram of the pre-filter unit 107, and FIG. 33B is a frequency characteristic diagram of a transfer function from the position command θ * to the control target position θL in the conventional motor control method.
FIG. 34 is a waveform diagram of a motor position deviation ΔθM and a control target position deviation ΔθL in a conventional motor control method.
FIG. 35 is a waveform diagram of a motor position deviation ΔθM and a control target position deviation ΔθL when the position proportional gain Kpp and the speed proportional gain Kvp are low without the pre-filter unit 107 in the conventional motor control method.
FIG. 36 is a waveform diagram of a position command θ * and a motor position command θM * in a conventional motor control method.
FIG. 37 is a waveform chart of T * in a conventional motor control method.
FIG. 38 is a view showing a mounting machine equipped with the present invention.
[Explanation of symbols]
1 Position command creation unit
2 Electric motor
3 Control target
4 Position detector
5 Vibration detector
6, 22, 43 Servo controller
7 Position command input section
8 Pre-filter section
9 Filter section
10 Parameter automatic setting section
11 Equivalent filter section
12 Command follow-up control unit
13 Position deviation calculator
14 Position control unit
15 Speed calculator
16 Speed deviation calculator
17 Speed control unit
18 Current control unit
20 Speed command generator
21 Speed detector
23 Speed command input section
24 Command follow-up control unit
30, 42 Compensation value application section
40 Command estimation unit
41 Equivalent internal filter

Claims (25)

A command input step of inputting a command to a motor or a control target connected to the motor,
A pre-filter step of applying the command to a filter having both a characteristic of lowering the gain of a predetermined frequency and a frequency in the vicinity thereof and a characteristic of suppressing a high-frequency gain, and outputting a following command value,
A command following control step of controlling the state quantity of the electric motor or the control target to follow the following command value,
A method for controlling an electric motor, comprising: A command input step of inputting a command to a motor or a control target connected to the motor,
A transfer function of a filter having both a characteristic of lowering the gain of a predetermined frequency and a frequency in the vicinity thereof and a characteristic of suppressing a gain in a high frequency band is equivalently converted into a sum of a constant term and a feedforward compensation term, and A feedforward type pre-filter step of outputting a follow-up command value by acting on a constant term, and outputting the feedforward compensation term compensation amount by acting on the command to a feedforward compensation term;
A command following control step of controlling the state quantity of the electric motor or the control target to follow the following command value based on the feedforward compensation term compensation amount and the following command value;
A method for controlling an electric motor, comprising: A command input step of inputting a command to a motor or a control target connected to the motor,
A command following control step of controlling the state quantity of the electric motor or the control target to follow the following command value based on the command based on the feedforward compensation term compensation amount and the following command value;
A command estimating step of outputting an estimated command estimating the command based on a state quantity inside the command following control step,
The transfer function of the filter having both the characteristic of lowering the gain of the predetermined frequency and the frequency in the vicinity thereof and the characteristic of suppressing the gain in the high frequency band is equivalently converted into the sum of a constant term and a feedforward compensation term, and the estimation command is obtained. An internal configuration type pre-filter step of operating the feed forward compensation term to output the feed forward compensation term compensation amount,
A method for controlling an electric motor, comprising: The pre-filter step, the feed-forward type pre-filter step or the internal configuration type pre-filter step, the gain of the predetermined frequency is particularly variable among the characteristics for lowering the gain of a predetermined frequency and a frequency around the predetermined frequency. The method for controlling an electric motor according to any one of claims 1 to 3, wherein the control is performed. The said pre-filter step, the said feed-forward type pre-filter step, or the said internal structure type pre-filter step changes the characteristic which suppresses the said high frequency gain according to an operation state, The Claims 1 characterized by the above-mentioned. The method for controlling an electric motor according to claim 4. The pre-filtering step, the feed-forward type pre-filtering step or the internal configuration type pre-filtering step automatically determines the characteristic for suppressing the high-frequency gain based on at least a parameter for determining the predetermined frequency. The method for controlling an electric motor according to any one of claims 1 to 5, characterized in that: 2. The method according to claim 1, wherein the pre-filtering step, the feed-forward type pre-filtering step, or the internal configuration type pre-filtering step includes a vibration frequency automatic setting step of automatically setting the predetermined frequency. 3. The control method for an electric motor according to claim 6. The vibration frequency automatic setting step, a vibration detection step of detecting the vibration of the control target, and a frequency determination step of extracting a vibration frequency from the detected vibration and determining the predetermined frequency, The method for controlling a motor according to claim 7. The motor control method according to claim 7, wherein the vibration frequency automatic setting step determines the predetermined frequency based on a vibration frequency of the electric motor. The method according to claim 7, wherein in the vibration frequency automatic setting step, a mathematical model of the electric motor and the control target is estimated based on a response of the electric motor, and the predetermined frequency is determined based on the mathematical model. Motor control method. The said predetermined frequency is a frequency near the anti-resonance frequency which the system from the torque which the said motor output to the position or the speed of the said motor has, The one of Claim 1 characterized by the above-mentioned. The control method of the electric motor according to the paragraph. A command input step of inputting a command to a motor or a control target connected to the motor,
A control step of controlling the state quantity of the electric motor or the control target to follow the command,
Has,
In the control step, the command is sent to a filter having both a characteristic of lowering a gain of a frequency near an anti-resonance frequency and a characteristic of suppressing a gain in a high frequency range, which have a system from the torque of the motor to the position or speed of the motor. And outputs a follow-up command value, and performs control having the same or equivalent characteristics as controlling the state quantity of the motor or the control target to follow the follow-up command value. Control method. A command input unit for inputting a command to a motor, or a control target connected to the motor,
A pre-filter unit that has a filter having both a characteristic of lowering the gain of a predetermined frequency and a frequency in the vicinity thereof and a characteristic of suppressing a high-frequency gain, and outputs a following command value by applying the command to the filter. ,
A command follow-up control unit that controls the state quantity of the electric motor or the control target to follow the follow-up command value,
A control device for a motor, comprising: A command input unit for inputting a command to a motor, or a control target connected to the motor,
A transfer function of a filter having both a characteristic of lowering the gain of a predetermined frequency and a frequency in the vicinity thereof and a characteristic of suppressing a gain in a high frequency band is equivalently converted into a sum of a constant term and a feedforward compensation term, and A feedforward type pre-filter unit that outputs a follow-up command value by acting on a constant term, and outputs a feedforward compensation term compensation amount by acting on the command to a feedforward compensation term;
A command following control unit that controls the state quantity of the electric motor or the control target to follow the following command value based on the feedforward compensation term compensation amount and the following command value,
A control device for a motor, comprising: A command input unit for inputting a command to a motor, or a control target connected to the motor,
A command follow-up control unit that controls the state quantity of the electric motor or the control target to follow the follow-up command value based on the command based on the feedforward compensation term compensation amount and the follow-up command value,
A command estimating unit that outputs an estimated command that estimates the command based on a state quantity inside the command following control unit,
The transfer function of the filter having both the characteristic of lowering the gain of the predetermined frequency and the frequency in the vicinity thereof and the characteristic of suppressing the gain in the high frequency band is equivalently converted into the sum of a constant term and a feedforward compensation term, and the estimation command is obtained. An internal configuration type pre-filter unit that outputs the feed forward compensation term compensation amount by acting on the feed forward compensation term,
A control device for a motor, comprising: The pre-filter unit, the feed-forward type pre-filter unit or the internal configuration type pre-filter unit, the gain of the predetermined frequency is particularly variable among the characteristics for lowering the gain of a predetermined frequency and a frequency around the predetermined frequency. The electric motor control device according to any one of claims 13 to 15, wherein: The said pre-filter part, the said feed-forward type pre-filter part, or the said internal structure type pre-filter part changes the characteristic which suppresses the said high frequency gain according to an operating state, The Claims 13 characterized by the above-mentioned. A control device for an electric motor according to claim 16. The pre-filter unit, the feed-forward type pre-filter unit or the internal configuration type pre-filter unit automatically determines a characteristic for suppressing the high-frequency gain based on at least a parameter for determining the predetermined frequency. The electric motor control device according to any one of claims 13 to 17, wherein: The said pre-filter part, the said feed-forward type pre-filter part or the said internal structure type pre-filter part has a vibration frequency automatic setting part which sets the said predetermined frequency automatically, The claim from Claim 13 characterized by the above-mentioned. The control device for an electric motor according to claim 18. The vibration frequency automatic setting unit, a vibration detection unit that detects the vibration of the control target, and a frequency determination unit that determines the predetermined frequency by extracting a vibration frequency from the detected vibration, The control device for a motor according to claim 19, wherein: 20. The motor control device according to claim 19, wherein the vibration frequency automatic setting unit determines the predetermined frequency based on a vibration frequency of the motor. The vibration frequency automatic setting unit estimates a mathematical model of the electric motor and the control target based on a response of the electric motor, and determines the predetermined frequency based on the mathematical model. Motor control device. The said predetermined frequency is a frequency near the anti-resonance frequency which the system from the torque which the said motor output to the position or the speed of the said motor has, The one of Claim 13 characterized by the above-mentioned. A control device for an electric motor according to the item. A command input unit for inputting a command to a motor, or a control target connected to the motor,
A control unit that controls the state quantity of the electric motor or the control target to follow the command,
Has,
The control unit is configured to control the filter having both a characteristic of lowering a gain of a frequency near an anti-resonance frequency and a characteristic of suppressing a gain in a high frequency range of the system from the torque of the electric motor to the position or speed of the electric motor. And outputs a follow-up command value, and performs control having the same or equivalent characteristics as controlling the state quantity of the motor or the control target to follow the follow-up command value. Control device. An apparatus comprising the control device according to any one of claims 13 to 24.

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