JP2019193408A - Vibration suppression device and linear motor control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration suppression device and a linear motor control device capable of reliably suppressing mechanical vibration generated by the operation of an actuator including a linear motor over a wide frequency range. SOLUTION: In a vibration suppressing device for suppressing the vibration of a machine body 30 generated by the operation of a main drive actuator 31 including a linear motor and a balancing actuator 32 by controlling the linear motor of the balancing actuator 32, a vibration suppressing control. The unit 10 extracts the fundamental wave component and the harmonic component of the drive frequency of the linear motor from the vibration detection signal of the machine body 30 or the gas force characteristic curve 12, and based on these components, issues a correction command for canceling the periodic disturbance. , 16n for generating each vibration component suppression control, and a signal obtained by adding the main command (command signal 2) and the correction command by the adding means 17 is input to the power amplifier 20 to drive the linear motor. To drive. [Selection diagram] Figure 1

Description

  The present invention relates to, for example, a linear compressor that compresses gas by reciprocating a piston with a linear motor, and a vibration suppressing device for reducing mechanical vibration generated by gas force accompanying the reciprocating motion of the piston, and the vibration. The present invention relates to a linear motor control device including a suppression device.

FIG. 5 shows a drive system for a linear compressor constituting the refrigerator, which is described in Patent Document 1.
5, 101 denotes a DC power source, 102 is a single-phase inverter composed of a semiconductor switching element _Q 1 to Q _4, 103 is a linear compressor, 104A, 104B is a linear motor, 105A, 105B are a piston, 106 is a cylinder, 107 is a piston This is a position sensor that obtains position information for preventing a collision between 105A and 105B.
In this prior art, an AC voltage is supplied to the drive coils of the linear motors 104A and 104B by the single-phase inverter 102, and the pistons 105A and 105B are reciprocated in opposite directions to compress the gas inside the cylinder 106 at a predetermined cycle. Inflated and supplied to the expander.

  Generally, in a linear compressor, gas suction (compression) and discharge are repeatedly performed by a reciprocating motion of a piston, and a gas force (gas pressure) is periodically changed. Since this change in gas force vibrates the housing of the compressor and causes noise and failure, it is important to suppress this mechanical vibration.

From the above background, as shown in Patent Documents 2 and 3, conventional techniques for suppressing mechanical vibration of a refrigerator or the like are known.
FIG. 6 shows a control system of the Stirling refrigerator described in Patent Document 2.
In FIG. 6, 200 is a fundamental frequency vibration control unit, 201 is an amplitude / phase adjustment unit, 202a and 202b are subtractors, 203a and 203b are position servo compensators, 300 is a Stirling refrigerator, 301 is a compressor, and 302a and 302b are A linear motor, 303a and 303b are pistons, 310 is a helium flow path, 321 is an expander, 322a and 322b are linear motors, 323 is a piston, 324 is a balance unit, and 325 is a regenerator. Here, stroke commands (position commands) Sa and Sb of linear motors 302 a and 302 b corresponding to the pistons 303 a and 303 b of the compressor 301 are input to the fundamental frequency vibration control unit 200.

  In this prior art, the position detection values Pa and Pb of the pistons 303a and 303b are fed back to the fundamental frequency vibration control unit 200, and the position servo compensators 203a and 203b are operated so as to eliminate the deviation from the stroke commands Sa and Sb. Drive commands Ma and Mb for the linear motors 302a and 302b are generated. Thereby, the position of piston 303a, 303b can be adjusted in real time, and the mechanical vibration of the compressor 301 can be reduced.

FIG. 7 is a configuration diagram of the vibration suppression system described in Patent Document 3.
In this conventional technique, mechanical vibration of the main machine 410 driven by the power control circuit 408 is suppressed by driving a motor 412 in an active vibration balancer 411 attached to the main machine 410.

In FIG. 7, the digital processor 400 includes a command input unit 401, a control algorithm 402, and a D / A conversion unit 403, and the main machine 410 receives the command output from the D / A conversion unit 403 via the power control circuit 408. Driven.
On the other hand, the vibration of the combined body of the main machine 410 and the active vibration balancer 411 is detected by the vibration sensor 413, and the detection signal is sent to the adaptive balancing signal generator 404 a, via the A / D converter 405 in the digital processor 400. 404b,..., 404n. The adaptive balancing signal generators 404a, 404b,..., 404n are based on the output signal of the A / D conversion unit 405 and based on a predetermined adaptive filter algorithm, the fundamental frequency component ω and the harmonic component 2ω, ..., an adaptive balanced signal with nω is generated. These adaptive balancing signals are combined by the adder 406 and input to the motor control unit 409 via the D / A conversion unit 407. By driving the motor 412 of the active vibration balancer 411 by the motor control unit 409, it is possible to cancel the vibrations of the fundamental wave component ω and the harmonic components 2ω,.

Japanese Patent No. 4096665 ([0016] to [0019], FIG. 1 etc.) US Pat. No. 5,535,593 (FIG. 2a etc.) JP-T-2015-530638 ([0019] to [0030], FIG. 1 etc.)

According to the prior art of Patent Document 2, it is possible to suppress the fundamental component of vibration by independently controlling the positions and strokes of the pistons 303a and 303b, but it is impossible to suppress the harmonic component. It is.
The prior art of Patent Document 3 can theoretically deal with fundamental wave components to a plurality of harmonic components, but the stability of the adaptive filter algorithm in the adaptive balanced signal generators 404a, 404b,. Due to problems such as the processing capability of the processor 400, it has been difficult to reliably suppress mechanical vibration at a low cost.

  SUMMARY OF THE INVENTION Accordingly, a problem to be solved by the present invention is to provide a vibration suppression device capable of reliably suppressing mechanical vibration generated in accordance with the operation of an actuator including a linear motor over a wide frequency range, and a linear motor including the vibration suppression device. It is to provide a control device.

In order to solve the above-described problem, the vibration suppressing device according to claim 1 is a vibration suppressing device that suppresses vibration of a machine main body generated by operation of an actuator including a linear motor by controlling the linear motor.
Disturbance estimation means for estimating periodic disturbance based on fundamental wave components and harmonic components of the driving frequency of the linear motor extracted from a signal relating to vibration of the machine body;
Periodic disturbance suppression calculating means for generating a correction command for canceling the periodic disturbance by feeding back the periodic disturbance to the periodic disturbance command;
An adding means for adding the main command for driving the linear motor and the correction command;
Means for driving the linear motor according to the output of the adding means;
It is provided with.

  The vibration suppression device according to claim 2 is the vibration suppression device according to claim 1, wherein the machine body is a linear compressor, and the linear compressor includes first and second actuators as the actuator, Each of the first and second actuators includes the linear motor and a piston that is driven by the linear motor and reciprocates in opposite directions, and signals related to vibrations of the machine body are the first and second actuators. It is a signal regarding the vibration which generate | occur | produces in the housing of the said linear compressor resulting from the change of the gas force accompanying the reciprocating motion of the said piston in the inside.

  A vibration suppression apparatus according to a third aspect is the vibration suppression apparatus according to the second aspect, wherein the linear motor that constitutes the first actuator is driven in accordance with the main command, and the linear motor that constitutes the second actuator is The driving is performed according to the output of the adding means.

  A vibration suppression apparatus according to a fourth aspect is the vibration suppression apparatus according to any one of the first to third aspects, wherein the disturbance estimation means uses a periodic disturbance observer to calculate the period from the signal related to the vibration of the machine body. The disturbance is estimated, and the ambient disturbance suppression calculating means calculates the correction command for canceling the periodic disturbance estimated by the periodic disturbance observer.

  A vibration suppression apparatus according to a fifth aspect is the vibration suppression apparatus according to the fourth aspect, wherein the main command and the correction command are a current command or a voltage command.

  A linear motor control device according to claim 6 is a power converter that supplies AC power to the linear motor by using the output of the adding means in the vibration suppression device according to any one of claims 1 to 5. It is characterized by controlling.

  According to the present invention, the fundamental wave component and the harmonic component of the drive frequency are extracted as disturbances from the vibration detection signal of the machine body, and the correction command calculated so that these components become 0 is added to the main command to By controlling the above, it is possible to reliably suppress the vibration of the machine body over a wide frequency range.

It is a block diagram which shows the schematic structure of embodiment of this invention. It is a wave form diagram which shows the relationship between the piston position in a linear compressor, and gas force. In the Example of this invention, it is a block diagram of the vibration suppression apparatus in the case of driving a linear compressor using an electric current command. It is a block diagram, such as a periodic disturbance observer and a periodic disturbance suppression calculating part, in the Example of this invention. 1 is a configuration diagram showing a drive system for a linear compressor described in Patent Document 1. FIG. It is a block diagram which shows the control system of the Stirling refrigerator described in patent document 2. It is a block diagram which shows the control system of the Stirling machine described in patent document 3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, FIG. 1 is a block diagram showing a schematic configuration of a vibration suppressing device according to the present embodiment. This vibration suppression device is used, for example, in a linear compressor constituting a Stirling refrigerator to suppress vibrations generated by reciprocating motion of a pair of pistons constituting an actuator.

In FIG. 1, a vibration suppression control unit 10 including a digital processor or the like includes a vibration sensor 11 or a gas force characteristic curve 12.
The vibration sensor 11 detects vibration of the housing of the machine body 30 of the linear compressor, and the vibration detection signal is input to the terminal a of the selector 13.
When the vibration suppression control unit 10 does not have the vibration sensor 11, data based on the gas force characteristic curve 12 in the memory is input to the terminal b of the selector 13. The gas force in the cylinder periodically changes due to the reciprocating motion of the piston in the machine body 30 and mechanical vibrations are generated due to this, but the fundamental wave component and each harmonic component can be measured in advance. Therefore, these data can be stored in advance in the memory as the gas force characteristic curve 12.

The selector 13 selects the input of the terminal a or the terminal b, and the first order component (fundamental wave component) filter 14 ₁ , the second order component filter 14 ₂ ,..., The nth order component filter 14 _n through the terminal c. Output to.
Respective subcomponents (components extracted or estimated as disturbances) extracted by the filters 14 _{1 to} 14 _n are input to the subtracting means 15 ₁ , 15 ₂ ,..., 15 _n to be “0” (target value). Are calculated, and these deviations are input to the primary vibration component suppression controller 16 ₁ , the secondary vibration component suppression controller 16 ₂ ,..., And the nth vibration component suppression controller 16 _n , respectively.
Each of the suppression controllers 16 ₁ , 16 ₂ ,..., 16 _n performs a calculation so that the deviation input to each of them becomes 0, generates a correction command, and these correction commands are sent to the switches S ₁ , S _2, ..., by inputting to the adder unit 17 via the S _n, is added to the command signal 2 as the main command.

The command signals 1 and 2 include, as information, a drive frequency, a current command, or a voltage command for the main drive actuator 31 and the balancing actuator 32 provided in the machine body 30, and the command signal 1 and the command signal 2 (main command). A signal obtained by adding the correction command is input to the power amplifier 20. The power amplifier 20 supplies power to the main drive actuator 31 and the balancing actuator 32, respectively.
Here, the main drive actuator 31 is configured by a linear motor 302a and a piston 303a as in the compressor 301 of FIG. 6, for example, and the balancing actuator 32 is similarly configured by a linear motor 302b and a piston 303b.
As shown in FIG. 1, the main drive actuator 31 and the balancing actuator 32 may be driven by one power amplifier 20, or the actuators 31 and 32 may be driven by individual power amplifiers.

Next, an example in which this embodiment is embodied will be described with reference to FIGS.
When the machine body 30 is a linear compressor of a refrigerator, mechanical vibrations generated in the housing due to the reciprocating motion of the pair of pistons are mainly (1) the inertial forces generated by the opposed pistons are not equal. (2) The periodic gas force acts as a disturbance due to the reciprocating motion of the piston.
Among these, regarding (1), if the thrust is controlled by controlling the current of each piston, the difference in inertial force can be completely offset. Further, it is known that the gas force (2) periodically changes according to the piston position as shown in FIG. These points are also disclosed in Huiming Zou, “Experimental investigation and performance analysis of a dual-cylinder opposed linear compressor”, Journal of Mechanical Science and Technology, August, 2011 (FIG. A.1).

ここで、周期的なガス力Ｆ_ｆｇａｓの直流成分は、０［Ｎ］である。また、数式１において、ａ_ｎ，ｂ_ｎはガス力のフーリエ係数を示す。 When the periodic gas force shown in FIG.

Here, the DC component of the periodic gas force F _fgas is 0 [N]. In Equation 1, a _n and b _n represent Fourier coefficients of gas force.

  Therefore, if a correction command that cancels a disturbance (gas force) of a predetermined frequency that suppresses the movement is added to the main command that moves each piston in a predetermined direction, a force that counters the disturbance is generated to suppress vibration. be able to. In constructing the vibration suppressing device, for the sake of convenience, the disturbance acts only on the drive system of one piston (corresponding to the balancing actuator 32 in FIG. 1), and the drive system of the other piston (also the main drive actuator). 31).

FIG. 3 shows a case where a linear compressor 30A (corresponding to the machine main body 30 in FIG. 1) is driven by giving a sine wave current command as a main command to the vibration suppression controller 10A (corresponding to the vibration suppression controller 10 in FIG. 1). It is a block diagram of a vibration suppression device.
In FIG. 3 and FIG. 4 described later, the current command is used for the main command and the correction command, but a voltage command may be used. In FIG. 3, mechanical vibration is detected by the vibration sensor 11, but as shown in FIG. 1, a gas force characteristic curve 12 may be used instead of the vibration detection signal by the vibration sensor 11.

  The linear compressor 30A includes two voice coil motors 31a and 32a, which are energy-saving linear motors, pistons (mechanical systems) 31c and 32c driven by the motors 31a and 32a, and addition means 31b and 32b, respectively. ing. The pair of pistons 31c and 32c are arranged to face each other and reciprocate in opposite directions to compress gas in an internal space of a cylinder (not shown).

  In the above configuration, the voice coil motor 31a, the adding means 31b, and the piston 31c constitute the main drive actuator 31 of FIG. 1, and the voice coil motor 32a, the adding means 32b, and the piston 32c similarly constitute the balancing actuator 32. As described above, the gas force as a disturbance is input to one of the adding means 32b, and the description will be continued assuming that it acts only on the balancing actuator 32.

The mechanical vibration of the housing of the linear compressor 30A is detected by the vibration sensor 11, and a vibration detection signal (acceleration A _det ) is output. This acceleration A _det is input to the periodic disturbance observer 50 in the vibration suppression control unit 10A to estimate the periodic disturbance.
The periodic disturbance observer 50 extracts a fundamental component and a harmonic component of the drive frequency of the balancing actuator 32 (voice coil motor 32a) included in the acceleration A _det , and a disturbance from these frequency components. And an inverse system 52 for estimation.

The inverse system 52 has P _2n (s) · P _2n ^{−1 with} respect to a transfer function P _2n (s) of an actual system including a current controller 74, a PWM inverter 22, a voice coil motor 32a, a piston 32c, and the like, which will be described later. It is a system of transfer function P _2n ⁻¹ (s) that satisfies (s) = 1. The inverse system 52 is designed including a current feedback control system and has a transfer characteristic corresponding to the frequency component of the vibration to be suppressed.

  The disturbance estimated by the periodic disturbance observer 50 is input to the periodic disturbance suppression calculation unit 60 and fed back to the periodic disturbance current command (usually 0) via the subtracting means 61 and 63 and the filter 62, thereby correcting the correction command (correction). Current command) is generated. Note that a filter having the same characteristics as the filter 62 is used for the frequency component extraction unit 51 in order to cause the value extracted by the frequency component extraction unit 51 to follow the periodic disturbance current command.

The correction current command output from the periodic disturbance suppression calculation unit 60 is added to the sine wave current command (main command) by the adding unit 15 and input to the current controller 74 via the subtracting unit 73 in the power amplifier 20A. . The sine wave current command is input to the current controller 72 via the subtracting means 71.
The current controllers 72 and 74 generate control commands so that the currents of the voice coil motors 31a and 32a follow the current commands, and output the control commands to the PWM inverters 21 and 22. The PWM inverters 21 and 22 The coil motors 31a and 32a are driven to control the reciprocating motion of the pistons 31c and 32c.

Next, FIG. 4 is a configuration diagram of the periodic disturbance observer 50 and the periodic disturbance suppression calculation unit 60 in FIG. 3, and is also described in, for example, Japanese Patent No. 5929863.
In FIG. 4, the compressor drive system 80 includes a main drive system 81 and a balancing system 82. The main drive system 81 is a block including the current controller 72 of FIG. 3, the PWM inverter 21, the voice coil motor 31a, the adding means 31b, the piston 31c, and the like, and the balancing system 82 is the current controller 74 of FIG. The block includes a PWM inverter 22, a voice coil motor 32a, an adding means 32b, a piston 32c, and the like. In FIG. 4, the illustration of the vibration sensor 11 of FIG. 3 is omitted.

In the frequency component extraction unit 51 of FIG. 4, the real part A _an and the imaginary part of the nth-order (n is a natural number) frequency component from the acceleration A _det detected by the vibration sensor of the compressor drive system 80 by performing the calculation of Equation 2. A _bn is extracted.

In order to calculate Formula 2, as shown in FIG. 4, the acceleration A _det is doubled, and the multiplication result of the cosine cos (nωt) and sine sin (nωt) of the fundamental component and the harmonic component of the drive frequency is low-passed. By passing through the filter G _F (s), the real part A _an and the imaginary part A _bn of the n-th order frequency component of the acceleration A _det are extracted. Here, A and ω correspond to the amplitude and frequency of the sine wave current command, respectively.
The vibration components included in A _an and A _bn are the parts where “*” is added to Equation 2, and these vibration components are blocked by the low-pass filter G _F (s). In the right side of Equation 2, a _an and a _bn are amplitudes, and a ₀ is a constant.

Further, as described above, the actual system 83 in FIG. 4 includes the balancing system 82 including the voice coil motor 32a, the piston 32c, the vibration sensor, and the like, and from the input current command to the vibration (acceleration A _det ) output. The overall system has a frequency transfer characteristic. The transfer characteristic from the position of the piston 32c to the housing of the linear compressor 30A can be obtained by an identification test.

Assuming that the transfer function of the real system 83 is P _2n (s), the output of the frequency component extraction unit 51 is multiplied by the inverse model of the transfer function P _2n ⁻¹ (s), and the estimated input current i is obtained via the separating unit 91. The real part (real part estimated value) I _an ^# and the imaginary part (imaginary part estimated value) I _bn ^# of _n ^# are calculated. Since these estimated values I _an ^# and I _bn ^# include a periodic disturbance component due to gas force, the real part current command I _an ^* and the imaginary part current command I _bn passed through the low-pass filter G _F (s). By subtracting ^* , the real part dI _an ^# and the imaginary part dI _bn ^# of the periodic disturbance current estimated value can be obtained.

By feeding back the real part dI _an ^# and the imaginary part dI _bn ^# of the periodic disturbance current estimated value described above to the real part dI _an ^* (= 0) and the imaginary part dI _bn ^* (= 0) of the periodic disturbance current command, respectively. The real part current command I _an ^* and the imaginary part current command I _bn ^* for suppressing the periodic disturbance are obtained.
By multiplying these real part current command I _an ^* and imaginary part current command I _bn ^* by cos (nωt) and sin (nωt), an n-th order correction current command i _cn ^* is generated. By applying this correction current command i _cn ^* to the actual system 83 and _adding the disturbance component i _neq2 and the sine wave current command (main command) Asin (ωt) as a current command, the voice coil motor 32a is driven, The mechanical vibration caused by the gas force changing with the reciprocating motion of 32c can be suppressed.

  3 and 4 are only one embodiment of the present invention. For example, instead of the periodic disturbance observer 50, a fundamental component of mechanical vibration such as a bandpass filter and harmonic components of each order can be extracted. A simple filter may be used.

  The present invention is not limited to a linear compressor, and can be used as a vibration suppressing device for various machine bodies including an actuator having a linear motor.

10, 10A: Vibration suppression control unit 11: Vibration sensor 12: Gas force characteristic curve 13: Selector 14 ₁ : 1st order component filter 14 ₂ : 2nd order component filter 14 _n : nth order component filter 15 ₁ to 15 _n : Subtraction Means 16 ₁ : Primary vibration component suppression controller 16 ₂ : Secondary vibration component suppression controller 16 _n : Nth order vibration component suppression controller 17: Addition means 20, 20A: Power amplifier 21, 22: PWM inverter 30A: Linear Compressor 30: Machine body 31: Main drive actuator 32: Balance actuator 31a, 32a: Voice coil motor 31b, 32b: Addition means 31c, 32c: Piston 50: Periodic disturbance observer 51: Frequency component extraction unit 52: Inverse system 61 63, 71, 73: Subtraction means 62: Filter 72, 74: Current controller 80 : Compressor drive system 81: main drive system 82: the balancing system 83: Real System 91: separating means S ₁ to S _n: switch

Claims (6)

In the vibration suppressing device that suppresses vibration of the machine body generated by the operation of the actuator including the linear motor by controlling the linear motor.
Disturbance estimation means for estimating periodic disturbance based on fundamental wave components and harmonic components of the driving frequency of the linear motor extracted from a signal relating to vibration of the machine body;
A periodic disturbance suppression calculating means for generating a correction command for canceling the periodic disturbance by feeding back the periodic disturbance to the periodic disturbance command;
An adding means for adding the main command for driving the linear motor and the correction command;
Means for driving the linear motor according to the output of the adding means;
A vibration suppressing device comprising: The vibration suppressing device according to claim 1,
The machine body is a linear compressor;
The linear compressor is
The actuator includes first and second actuators,
The first and second actuators each include the linear motor and a piston driven by the linear motor and reciprocating in opposite directions;
The signal related to the vibration of the machine body is a signal related to the vibration generated in the housing of the linear compressor due to a change in gas force accompanying the reciprocating motion of the piston in the first and second actuators. Vibration suppression device. In the vibration suppression device according to claim 2,
A vibration suppressing apparatus, wherein a linear motor constituting the first actuator is driven according to the main command, and a linear motor constituting the second actuator is driven according to an output of the adding means. In the vibration suppression device according to any one of claims 1 to 3,
The disturbance estimation means estimates the periodic disturbance from a signal related to vibration of the machine body using a periodic disturbance observer,
The vibration suppression apparatus according to claim 1, wherein the ambient disturbance suppression calculating means calculates the correction command for canceling the periodic disturbance estimated by the periodic disturbance observer. In the vibration suppression device according to claim 4,
The vibration suppression apparatus, wherein the main command and the correction command are a current command or a voltage command.   A linear motor control device that controls a power converter that supplies AC power to the linear motor by using the output of the adding means in the vibration suppressing device according to any one of claims 1 to 5. .

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