JP2023088149A - Synchronous operation device - Google Patents

Abstract

To achieve absolute synchronous operation without the need for a high-precision position sensor.SOLUTION: A synchronous operation system 1 includes: a command completion flag operator 240 that outputs a flag Fr that is 0 from immediately after power-on until just before a position command clear command is turned on and then turned off and then becomes 1; an initial position detector 224 that outputs an initial value Cn0 of a rotational position Cn of a machine 207 from a position sensor 211, a motor home sensor 222, and a machine home sensor 223, and a flag Fo that changes from 0 to 1 at the time of outputting Cn0; a rotary position command operator 229 that clears a rotary position command Pn when a position command clear command is turned on and updates Pn by a position command change amount ΔPn when a position command clear command is turned off; and a machine rotation position operator 225 that calculates Cn by accumulating the output pulses of the position sensor 211 with Cn0 as an initial value when Fo is 1. The synchronous operation system 1 controls a motor 206 with a predetermined speed command when a product of Fr and Fo is 0 and controls the motor 206 so that the Cn follows Pn when the product is 1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a synchronous operation device for synchronizing and operating a plurality of machines that are not physically connected.

2. Description of the Related Art Conventionally, there is known a synchronous operation device that operates by synchronizing the rotational speeds and rotational positions of machines driven by a plurality of motors with high accuracy.

FIG. 4 shows a conventional synchronous operation device disclosed in Patent Document 1. As shown in FIG. The slave 2 includes a machine 207 driven by a motor 206 via a gear 208, a speed command converter 201 that multiplies the reference speed command from the master 1 by the reciprocal of the gear ratio of the gear 208, and outputs the speed command from the master 1. A position controller 202 that amplifies and outputs the deviation between the reference position command and the rotational position output from the position sensor 210; an adder 203 that adds the output of the speed command converter 201 and the output of the position controller 202; A speed controller 204 outputs a torque command such that the rotation speed of the output of the speed sensor 209 follows the output of the speed controller 203 to the speed command, and the motor 206 outputs torque so that the output torque of the motor 206 follows the output torque of the speed controller 204. and a torque controller 205 that controls 206 . A speed sensor 209 for detecting the rotational speed of the motor 206 is attached to the motor 206 , and a position sensor 210 for detecting the rotational position of the machine 207 is attached to the machine 207 . With the above configuration, the rotational position of the machine 207 can be controlled according to the reference position command from the master 1. FIG.

Although not shown, the slave 3 has the same configuration as the slave 2, and includes a motor 306, a gear 308, a machine 307, a speed sensor 309, a position sensor 310, a speed command converter 301, a position controller 302, an adder 303, a speed It is composed of a controller 304 and a torque controller 305 . Even if the gear ratio of the gear 308 of the slave 3 is different from that of the gear 208 of the slave 2, the speed command converter 301 multiplies the reference speed command from the master 1 by the reciprocal of the gear ratio of the gear 308 and outputs it. The rotational position of the machine 207 of the slave 3 and the rotational position of the machine 307 of the slave 3 can be the same.

FIG. 5 shows a conventional synchronous operation device disclosed in Patent Document 2. As shown in FIG. The slave 4 includes a motor 206, a position sensor 211, a gear 208, a machine 207, a speed converter 219, position change detectors 214 and 220, a total draw ratio setter 218, and multipliers 212 and 213. , an adder/subtractor 215 , an accumulator 216 , an amplifier 217 , an adder 203 , a speed controller 204 and a torque controller 205 .

The multiplier 212 obtains the product of the reference speed command from the master 1 and the output of the general draw ratio setter 218 and outputs it as a command corresponding to the rotational speed of the motor 206 . A position change detector 214 outputs a change ΔP0 between the reference position command from the master 1 and a predetermined period Ts. ΔP0 is multiplied by the output of the total draw ratio setter 218 by the multiplier 213 and corresponds to the rotation position change between Ts of the motor 206 . On the other hand, the position change detector 220 receives the output of the position sensor 211 that detects the rotational position of the motor 206 and outputs the rotational position change ΔCn of the motor 206 between Ts. The adder/subtractor 215 obtains the position change deviation by subtracting the motor position change output from the position change detector 220 from the position change command equivalent output from the multiplier 213 . When it is input to the accumulator 216 and accumulated, it becomes equivalent to the positional deviation and becomes a speed command for suppressing the positional deviation via the amplifier 217. It becomes a speed command for the motor 206 . A speed converter 219 receives the output of the position sensor 211 , performs differential arithmetic processing, and outputs the rotational speed of the motor 206 . A speed controller 204 amplifies the deviation between the speed command output from the adder 203 and the output of the speed converter 219 and outputs it as a torque command. A torque controller 205 controls the motor 206 so that the output torque of the motor 206 conforms to the torque command output from the speed controller 204 . With the above configuration, the rotational speed of the motor 206 can be set to a value obtained by multiplying the reference speed command from the master 1 by the total draw ratio output from the total draw ratio setter 218, and the rotational speed of the machine 207 can be set to the gear of the gear 208. It can be a ratio.

Although not shown, the slave 5 has the same configuration as the slave 4, and includes a motor 506, a position sensor 511, a gear 508, a machine 507, a speed converter 519, position change detectors 520 and 514, A total draw ratio setter 518 , multipliers 512 and 513 , an adder/subtractor 515 , an accumulator 516 , an amplifier 517 , an adder 503 , a speed controller 504 and a torque controller 505 are provided. For example, if the output of the general draw ratio setter 218 of the slave 4 is the reciprocal of the gear ratio for the gear 208, and the output of the total draw ratio setter 518 of the slave 5 is the reciprocal of the gear ratio for the gear 508, then the gear 208 and the gear 508 Even though the gear ratios are different, the rotational speeds of machine 207 and machine 507 can be the same.

JP 2006-254525 A JP 2019-165527 A

However, according to the synchronous operation device disclosed in Patent Document 1, although any value can be selected as the gear ratio of the physical gears of the motor and the machine, the machine requires a highly accurate position sensor. Moreover, the initial value of the accumulator 216 is not shown in Patent Document 2. If the initial values of the accumulator 216 and the accumulator 516 are not set correctly, absolutely synchronous operation in which the rotational positional relationship between the machines 207 and 507 can be fixed at a predetermined value cannot be realized.

SUMMARY OF THE INVENTION An object of the present invention, which has been made in view of such circumstances, is to provide a synchronous operation device that does not require a highly accurate position sensor and can realize an absolutely synchronous operation.

In order to solve the above problems, a synchronous operation device according to one embodiment is a synchronous operation device including a plurality of slaves, the slaves each having a machine, a motor for driving the machine, and a rotational position of the motor. a position sensor for outputting a pulse with polarity in the direction of rotation according to the rotation direction; a motor origin sensor for outputting a pulse for determining one predetermined position during one rotation of the motor; and a one predetermined position during one rotation of the machine. Equipped with a mechanical origin sensor for outputting a pulse for determining a position, and a control device for controlling the motor, a position command clear command from the master, and when the position command clear command is set to 0 when on, the position command clear command When is off, it receives a reference position command obtained by integrating the reference speed command of the reference machine at predetermined intervals, and the control device receives the position command clear command immediately after the power is turned on until immediately before it is turned off. an initial value Cn0 of the rotational position Cn of the machine, and the initial value from a command completion flag calculator that outputs a command completion flag that becomes 1 after 0; an initial position detector that outputs an origin complete flag that changes from 0 to 1 at the time Cn0 is output; a rotational position command Pn is cleared when the position command clear command is ON; a rotational position command calculator for updating the rotational position command Pn by a position command change amount ΔPn obtained using the reference position command change amount ΔP0; a machine rotation position computing unit that calculates the rotation position Cn of the machine by accumulating the output pulses of the position sensor and outputs the result; The rotational speed of the motor is controlled, and when the product is 1, the motor is controlled so that the rotational position Cn of the machine follows the rotational position command Pn.

Further, in order to solve the above problems, a synchronous operation device according to one embodiment is a synchronous operation device including a plurality of slaves, wherein the slaves each include a machine, a motor for driving the machine, and a drive for driving the motor. A position sensor that outputs a pulse with polarity in the direction of rotation according to the rotational position, a motor origin sensor that outputs a pulse for determining a predetermined position at one point during one rotation of the motor, and one point during one rotation of the machine. and a control device for controlling the motor, the position command clear command from the master and the position command clear command are set to 0 when on and the position command When the clear command is off, the reference position command obtained by integrating the reference speed command of the reference machine is received at predetermined intervals, and the control device turns off the position command clear command once after the power is turned on. an initial value Cn0 of the rotational position Cn of the machine obtained from the position sensor, the motor origin sensor, and the mechanical origin sensor; an initial position detector that outputs an origin completion flag that changes from 0 to 1 at the time of outputting an initial value Cn0; and a synchronous position command change amount calculator for outputting a value ΔPnx as a position command change amount ΔPn obtained by using the change amount ΔP0 between the predetermined cycles of the reference position command when the command completion flag is 1. , the origin completion flag is sampled at the predetermined intervals, and when the origin completion flag is 0, it is set to 0; when the origin completion flag changes to 1, it is set to the rotational position Cn; When the absolute mechanical rotation position change calculator outputs a value ΔCnx as the number of output pulses ΔCn of the position sensor during the predetermined period, and the position deviation Pi immediately after the power is turned on is set to 0, and the reference position command is received. every time, the positional deviation Pi is updated by the difference ΔPi between the value ΔPnx and the value ΔCnx, and when the product of the command completion flag and the origin completion flag is 0, the rotation speed of the motor is increased by a predetermined speed command. The motor is controlled so that the positional deviation Pi becomes zero when the product is one.

Further, in one embodiment, when the machine is driven by the motor with physical gears having a gear ratio of Da/Db, the machine is coupled to the reference machine with virtual gears having a gear ratio of Ea/Eb. Assuming that the number of output pulses per one rotation of the position sensor is Pmn, and that the reference position command changes by an integer in the range of 0 to Pm0-1 in one rotation of the reference machine, (Db*Ea*Pmn )/(Da*Eb*Pm0) is defined as the total gear ratio An/Bn.
and the F may be the remainder of the division when obtaining the previous ΔPn.

Further, in one embodiment, when the machine is driven by the motor with a physical gear having a gear ratio Da/Db, the initial position detector detects the The initial value of the rotational position Cn is set by measuring the number of output pulses of the position sensor between the pulse output of the mechanical origin sensor and the pulse output of the motor origin sensor, and the gear ratio Da/Db is set to 1. In the case of excess, the initial value of the rotational position Cn is set by measuring the number of output pulses of the position sensor between the pulse output of the motor origin sensor and the pulse output of the mechanical origin sensor, and the gear ratio When Da/Db is 1, the initial value of the rotational position Cn may be set according to the pulse output timing of the motor origin sensor.

Furthermore, in one embodiment, the timing for receiving the reference position command is input, the variation time is obtained by PLL (Phase Locked Loop) processing, which is the difference between the average point of the timing and the timing, and the variation time is calculated. A position command correction value may be obtained according to the position command correction value, and the rotational position command Pn may be corrected with the position command correction value.

Furthermore, in one embodiment, the timing for receiving the reference position command is input, the variation time, which is the difference between the average time point of the timing and the timing, is obtained by PLL processing, and the position command is determined according to the variation time. A correction value may be obtained, and the position deviation Pi may be corrected with the position command correction value.

Further, in one embodiment, when the position command clear command is on, the slave sets a position command clearing signal and transmits it to the master, and after a predetermined time has passed since the position command clear command is off, the position command clear command is turned off. clearing a command clearing signal and transmitting it to the master, the master continuing to turn on the position command clearing command until receiving the set position command clearing signal from all the slaves; When the ON time of the position command clear command exceeds a predetermined value, or when the master receives the position command clearing signal that is set even though the ON of the position command clear command has not been transmitted. It can be judged as abnormal.

Furthermore, in one embodiment, when the output pulse of the motor origin sensor or the mechanical origin sensor is a square wave, the initial position detector detects the position between the rising edge or the falling edge of the square wave and the opposite edge thereof. The output pulse number of the position sensor may be measured, and if the measured value is within a predetermined range, it may be determined that the output pulse of the motor origin sensor or the mechanical origin sensor is valid.

Further, in one embodiment, each of the slaves drives the motor based on the reference speed command received from the master, and the master controls the position command clear command in the ON state, A difference between the rotational position command Pn and the rotational position Cn may be received as a position deviation from a predetermined slave, and the position command clear command may be turned off at the timing when the absolute value of the position deviation becomes minimum. .

Further, in one embodiment, each of the slaves drives the motor based on the reference speed command received from the master, and the master controls the position command clear command in the ON state, The positional deviation Pi may be received from a predetermined slave, and the positional command clear command may be turned off at the timing when the absolute value of the positional deviation Pi becomes minimum.

ADVANTAGE OF THE INVENTION According to this invention, the synchronous operation apparatus which can implement|achieve an absolute synchronous operation without requiring a highly accurate position sensor can be provided.

1 is a block diagram showing a configuration example of a synchronous operation device according to a first embodiment of the present invention; FIG. FIG. 10 is a diagram showing a waveform example of an output signal of an incremental encoder; FIG. 5 is a block diagram showing a configuration example of a synchronous operation device according to a second embodiment of the present invention; 1 is a block diagram showing a first configuration example of a conventional synchronous operation device; FIG. FIG. 3 is a block diagram showing a second configuration example of a conventional synchronous operation device;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
A synchronous operation device 10 according to a first embodiment of the present invention will be described with reference to FIG. The synchronous operation device 10 has a plurality of slaves. Although the number of slaves may be three or more, a slave configuration of two slaves 60 and 61 is shown here, and the internal configuration of the slave 61 is the same as that of the slave 60 (not shown). Slave 60 comprises a machine 207 driven by motor 206 through gear 208 . The machine 207 is equipped with a machine origin sensor 223 that outputs a pulse that determines one predetermined position during one revolution of the machine 207 .

The motor 206 has a position sensor 211 that outputs a pulse with polarity in the rotational direction according to the rotational position of the motor 206, and a motor origin sensor 222 that outputs a pulse for determining one predetermined position during one rotation of the motor 206. is attached. The position sensor 211 and the motor origin sensor 222 are incremental encoders that output square-wave A and B signals whose phases are shifted by 90 degrees according to the rotational position, and a square-wave Z signal that is generated once per rotation. may

FIG. 2 is a diagram showing an output waveform example of the incremental encoder described above. The pulse output of the position sensor 211 is equivalent to the rising and falling edges of the A signal and B signal in FIG.

The master 1 and the slaves 60 and 61 exchange information via a communication cable 234 through high-speed, synchronous field network communication such as EtherCAT (registered trademark).

The master 1 simultaneously transmits a reference machine reference speed command, a position command clear command, and a reference position command to the plurality of slaves 60 and 61 at predetermined intervals. The reference position command is assumed to be 0 when the position command clear command is ON, and the reference speed command transmitted from the master 1 is integrated when the position command clear command is OFF.

A control device 30 that controls the motor 206 includes a speed controller 204, a torque controller 205, a speed converter 219, position change detectors 220 and 232, an initial position detector 224, and a machine rotation position calculator. 225, adders 226 and 250, a position controller 227, an adder/subtractor 228, a rotational position command calculator 229, a position command change calculator 230, a transmission/reception processor 233, multipliers 236, 237, 251 , a command completion flag calculator 240 , a PLL 252 and a speed command converter 261 .

The transmission/reception processor 233 receives a reference speed command, a position command clear command, and a reference position command of the reference machine from the master 1 at predetermined intervals, and transmits the position deviation Pi to the master 1 . Here, the "reference machine" is a virtual machine that serves as a reference, but it may be one of a plurality of slaves that serves as a reference. The transmission/reception processor provided in the slave 61 also receives the reference speed command, the position command clear command, and the reference position command from the master 1 at the same timing as the transmission/reception processor 233 .

The position change amount detector 232 outputs the change amount ΔP 0 of the reference position command output from the transmission/reception processor 233 to the position command change amount calculator 230 .

The position command change calculator 230 obtains the position command change ΔPn and outputs it to the rotational position command calculator 229 . Specifically, the number of teeth of the gear 208 on the motor 206 side is Da, and the number of teeth on the machine 207 side is Db. Assuming that the number of teeth on the machine side is Ea, the number of teeth on the machine 207 side is Eb, and the reference position command changes by an integer in the range of 0 to Pm0-1 per rotation of the reference machine, the number of teeth per rotation of the position sensor 211 is If the number of output pulses is Pmn and the irreducible fraction of (Db*Ea*Pmn)/(Da*Eb*Pm0) is defined as the total gear ratio An/Bn, the position command change ΔPn is ΔPn=(An*ΔP0+F) /Bn (1)
Ask for Here, all the variables in equation (1) are integer values, and F is the remainder of the division by Bn when obtaining the previous ΔPn. Therefore, for the next calculation, An*ΔP0+F-ΔPn*Bn (2)
It is necessary to update the remainder F with . This makes it possible to obtain the position command variation ΔPn without accumulated error.

A rotational position command calculator 229 obtains a rotational position command Pn and outputs it to the adder/subtractor 228 . The rotational position command Pn is set to 0 (cleared) when the position command clear command output from the transmission/reception processor 233 is ON, and when the position command clear command is OFF, the position command change ΔPn output from the position command change calculator 230 is accumulated ( Pn is updated by ΔPn). The rotational position command Pn changes between 0 and Pmn*Db/Da-1 when the machine 207 rotates once. Suppose that the machine 207 varies in the range of 0 to Pmn*Db-1 with the number of teeth Da revolutions. Since this process is executed simultaneously in all slaves, the rotational position commands of each slave change absolutely synchronously.

The speed command converter 261 multiplies the reference speed command by (Db*Ea)/(Da*Eb) to obtain the speed of the motor 206 that drives the machine 207, which is virtually connected to the reference machine by the virtual gear, through the gear 208. A motor reference speed command, which is a command, is obtained and output to multiplier 251 and adder 226 .

The machine origin sensor 223 outputs to the initial position detector 224 a pulse that determines one predetermined position during one revolution of the machine 207 .

The initial position detector 224 measures the number of output pulses of the position sensor 211 between the pulse output of the mechanical origin sensor 223 and the pulse output of the motor origin sensor 222 when the gear ratio Da/Db of the gear 208 is less than 1. By doing so, an initial value Cn0 of the rotational position Cn of the machine 207 is set and output to the machine rotational position calculator 225 . For example, when the number of teeth Da=3 and the number of teeth Db=5, the output pulse number of the position sensor 211 between the pulse output of the mechanical origin sensor 223 and the pulse output of the motor origin sensor 222 has three different values. exists. If these three values are known in advance, even if the reproducibility of the accuracy of the mechanical origin sensor 223 is low due to low responsiveness of the mechanical origin sensor 223 or mechanical vibration, the motor origin can be detected from the pulse output of the mechanical origin sensor 223. By comparing the result of measuring the number of output pulses of the position sensor 211 until the pulse output of the sensor 222 and three known values in advance and selecting the closest value for use, an accurate mechanical origin sensor can be obtained. H.223 output positions can be determined. As a result, the correct rotational position Cn of the machine 207 can be obtained as the initial value Cn0.

In a similar way of thinking, when the gear ratio Da/Db exceeds 1, by measuring the number of output pulses of the position sensor 211 between the pulse output of the motor origin sensor 222 and the pulse output of the mechanical origin sensor 223, An initial value Cn0 of the rotational position Cn can be set. Further, when the gear ratio Da/Db is 1, the initial value Cn0 of the rotational position Cn is set according to the pulse output timing of the motor origin sensor 222 .

Also, the initial position detector 224 outputs to the multiplier 236 an origin completion flag Fo that is 0 until the initial value Cn0 is obtained for the first time after the power is turned on and then becomes 1.

The position change detector 220 inputs the output pulse of the position sensor 211 for detecting the rotational position of the motor 206 and outputs the rotational position change ΔCn of the motor 206 to the mechanical rotational position calculator 225 .

The machine rotational position calculator 225 obtains the rotational position Cn of the machine 207 by accumulating the change amount ΔCn of the output of the position sensor 211 by the position change detector 220 with Cn0 as an initial value, and outputs it to the adder/subtractor 228. . Here, the rotational position Cn changes in the range of 0 to Pmn*Db-1 when the machine 207 rotates Da, similarly to the rotational position command Pn. The adder/subtractor 228 obtains the difference between the rotational position command Pn and the rotational position Cn as the position deviation Pi, and outputs it to the transmission/reception processor 233 and the adder 250 .

The PLL 252 receives the timing at which the transmission/reception processor 233 receives the reference position command from the master 1, and obtains the processing variation time Δt, which is the difference between the timing and the average time of the timing, by PLL processing. output to

A multiplier 251 multiplies the processing variation time Δt by the reference speed command output from the speed command converter 261 to obtain a position command correction value Phn corresponding to the processing variation time Δt.

The adder 250 corrects the positional deviation Pi obtained by the adder/subtractor 228 by the position command correction value Phn to obtain the positional deviation at the same timing as the rotational position Cn output from the mechanical rotational position calculator 225. Obtainable.

A command completion flag computing unit 240 receives a position command clear command, and outputs a command completion flag Fr that is 0 until immediately before the position command clear command is turned ON immediately after the power is turned on and then becomes 1 thereafter.

Position controller 227 amplifies the position deviation and outputs it to multiplier 237 as a speed command correction value.

The multipliers 236 and 237 and the adder 226 add the output of the position controller 227 to the motor reference speed command output from the speed command converter 261 only when both the command completion flag Fr and the origin completion flag Fo are 1. Input to speed controller 204 .

A speed converter 219 receives the output of the position sensor 211 , performs differential arithmetic processing, and outputs the rotational speed of the motor 206 .

The speed controller 204 amplifies the deviation between the speed command output from the adder 226 and the output of the speed converter 219 and outputs it as a torque command.

A torque controller 205 controls the motor 206 so that the output torque of the motor 206 conforms to the output torque command of the speed controller 204 .

Command completion flag calculator 240, position controller 227, multipliers 236 and 237, adder 226, speed converter 219, speed controller 204, and torque controller 205 described above generate a command completion flag Until both Fr and origin completion flag Fo become 1, only the speed control by the motor reference speed command output from the speed command converter 261 is performed. , so that the positional deviation Pi is zero. That is, when the product of the command completion flag Fr and the origin completion flag Fo is 0, the rotational speed of the motor 206 is controlled by the motor reference speed command output from the speed command converter 261, and when the product is 1, the rotational position command Pn The motor 206 is controlled so that the rotational position Cn of the machine 207 follows.

The derivation of the above equation (1) will be explained below. A change in the reference position command by ΔP0 means that the reference machine has rotated by ΔP0/Pm0. Since it is assumed that the reference machine and the machine 207 are connected by a virtual gear with a gear ratio of Ea/Eb, a change in the reference position command by ΔP0 means that the machine 207 is (Ea/Eb)*( ΔP0/Pm0). Since the motor 206 is connected to the machine 207 by a gear 208 with a gear ratio of Da/Db, a change in the reference position command by ΔP0 means that the motor 206 rotates by Db/Da*Ea/Eb*ΔP0/Pm0. Become. The relationship between position command variation ΔPn of the position sensor 211 that outputs pulses of Pmn per rotation and
ΔPn/Pmn=(Db/Da)*(Ea/Eb)*(ΔP0/Pm0) (3)
Since
ΔPn=An*ΔP0/Bn (4)
becomes. If the division by Bn in Equation (4) is not divisible, the error is accumulated, so the remainder of the division is carried over to the next calculation as in Equation (1).

When the output waveform of the motor origin sensor 222 or mechanical origin sensor 223 is a rectangular wave like the Z signal in FIG. The number of output pulses of the position sensor 211 is measured, and whether or not the motor origin sensor 222 or the mechanical origin sensor 223 is valid is determined based on whether or not it is within a predetermined range (the output pulse is determined to be valid if it is within a predetermined range). . For example, in the case of FIG. 2, the number of edges of the A signal and the B signal corresponding to the output pulse of the position sensor 211 is 4 in the period from the falling edge to the rising edge of the Z signal. In other words, when the total number of output pulses corresponding to the position sensor 211 in the period from the falling edge to the rising edge of the Z signal is other than 4, the Z signal is judged to be invalid and ignored, and when it is 4, it is judged to be valid. For example, the trailing edge point of the Z signal is set as the output pulse point of the motor origin sensor 222 or mechanical origin sensor 223 . By doing so, erroneous detection of the outputs of the motor origin sensor 222 and the mechanical origin sensor 223 can be suppressed, and noise mixed in the output of the motor origin sensor 222 and the mechanical origin sensor 223 prevents normal synchronous operation. It is possible to suppress the occurrence of the problem that it becomes impossible.

Since the rotational position of each slave machine operated synchronously is controlled so that the positional deviation from the rotational position command Pn becomes 0, machines with a very large positional deviation at the start of position control will greatly change their rotational speeds. to minimize the position deviation. Therefore, it is difficult to synchronize the operation of machines in which problems occur due to a large change in rotational speed. Therefore, the following processing may be further performed.

In the state where the master 1 sends the position command clear command ON and the reference speed command, and receives the position deviation from each slave, each slave stops position control at Pn=0 and starts each operation based on the reference speed command. The slave motor 206 is in a state of being driven. In this state, the position command clear command is turned off, for example, at the timing when the absolute value of the position deviation received from the slave 60 is minimized. Then, since the slave 60 starts position control when the position deviation becomes minimum, the speed correction by the position control can be small, and the transient state at the time of shifting to the position control can be suppressed to a minimum. It becomes possible.

If all the slaves 60 and 61 cannot normally receive the position command clear command from the master 1, normal synchronous operation cannot be performed. Therefore, the following processing may be further performed. When the position command clear command is on, the slaves 60 and 61 set the position command clearing signal and transmit it to the master 1, and clear the position command clearing signal after a predetermined time has passed since the position command clear command is off. Send to master 1. The master 1 continues to transmit the ON position command clear command until it receives the set position command clearing signals from all the slaves. The master 1 determines that there is an error when the ON time of the position command clear command exceeds a predetermined value, or when the position command clearing signal is set even though the position command clear command ON is not transmitted. to decide.

(Second embodiment)
Next, a synchronous operation device 11 according to a second embodiment of the present invention will be described with reference to FIG. The synchronous operation device 11 has a plurality of slaves. Although the number of slaves may be three or more, a slave configuration of two slaves 70 and 71 is shown here, and the internal configuration of the slave 71 is the same as that of the slave 70 (not shown).

A control device 33 that controls the motor 206 includes a speed controller 204, a torque controller 205, a speed converter 219, position change detectors 220 and 232, an initial position detector 224, and an absolute mechanical rotational position change. minute calculator 235, adders 226, 250, position controller 227, position command change minute calculator 230, transmission/reception processor 233, multipliers 236, 237, 251, accumulator 238, adder/subtractor 239 , a command completion flag calculator 240 , a synchronous position command change calculator 241 , a PLL 252 and a speed command converter 261 . In the configuration of the slave 70, description of the same configuration as that of the slave 60 in FIG. 1 will be omitted.

Synchronous position command change calculator 241 receives command completion flag Fr from command completion flag calculator 240 and receives position command change ΔPn from position command change calculator 230 . Then, the synchronous position command change computing unit 241 samples the command completion flag Fr at predetermined intervals, sets the command completion flag Fr to 0 when the command completion flag Fr is 0, and sets the command completion flag Fr to 1 when the command completion flag Fr is 1. A value .DELTA.Pnx, which is the position command change amount .DELTA.Pn obtained using the change amount .DELTA.P0 between cycles, is output to the adder/subtractor 239. FIG.

The absolute mechanical rotational position change calculator 235 receives the origin completion flag Fo and the initial value Cn0 of the rotational position Cn from the initial position detector 224, and inputs the rotational position change ΔCn of the motor 206 from the position change detector 220. do. Then, the origin completion flag Fo is sampled at predetermined intervals. When the origin completion flag Fo is 0, it is set to 0. When the origin completion flag Fo changes to 1, it is set to the rotation position Cn. outputs to the adder/subtractor 239 a value ΔCnx which is the number of output pulses ΔCn of the position sensor 211 during a predetermined period.

The adder/subtractor 239 outputs the difference ΔPi between ΔPnx and ΔCnx to the accumulator 238 .

Accumulator 238 accumulates ΔPi to obtain position deviation Pi. The position deviation Pi is 0 immediately after the power is turned on, and is updated by the difference ΔPi between the value ΔPnx and the value ΔCnx each time the reference position command is received. This positional deviation Pi is exactly the same as the positional deviation Pi of the first embodiment shown in FIG.

(effect)
Next, the effects of the present invention will be described. According to the invention according to claim 1 or claim 2, there is no need to attach highly accurate position sensors to the machines 60 and 61 of the slave 2 . Further, according to the invention according to claim 1, the initial value of the machine position can be correctly set, according to the invention according to claim 2, the initial value of the position deviation can be correctly set, and according to the invention according to claim 1 or 2, all the slaves can be set correctly. can be cleared at the same time, it becomes equivalent to the initial value setting of the accumulator 216 described in Patent Document 2, so that absolute synchronous operation can be realized.

Further, in the synchronous operation device described in Patent Document 1, the virtual gear ratio between the machine 207 of the slave 2 and the machine 307 of the slave 3 is equivalent to being connected by a virtual gear. There is a problem that the speed ratio cannot be set by In this regard, according to the third aspect of the present invention, it is possible to obtain the change in the position command in consideration of the virtual gear ratio, so it is possible to solve this problem.

Further, in Patent Document 2, in the case of a gear ratio having an arbitrary value below the decimal point, even if the multiplier 213 performs double-precision floating-point arithmetic, there will always be an arithmetic error, and the accumulator 216 , the synchronization of the rotational positions of the machine 207 of the slave 4 and the machine 507 of the slave 5 cannot be maintained. In order to avoid this, Patent Document 2 introduces an integer constant, but it can be applied only when the number of significant digits of the gear ratio is finite. For example, in the case of a gear ratio of 3/7, the reciprocal is an infinite decimal, so there is a problem that even if an integer constant is used, the synchronization gradually deviates. In this regard, according to the third aspect of the invention, since the position command change can be obtained without accumulated error, the synchronism of the rotational positions of the slave machines can be maintained, thereby solving this problem. becomes possible.

Also, in order to obtain the absolute rotational position of the machine, a mechanical origin sensor is used that outputs a pulse that determines one predetermined position during one rotation of the machine. Predetermined position detection deviation may occur depending on the speed. Machine vibrations may also cause deviation in detection of the predetermined position. In order to avoid this, it has been proposed to use a motor origin sensor of the motor shaft with high speed response and high accuracy instead of the mechanical origin sensor. However, if the motor and machine are connected by physical gears, the position of the machine cannot be uniquely determined from the output of the motor origin sensor, so there is a problem that the motor origin sensor cannot be used as a substitute. In this regard, according to the invention according to claim 4, it is possible to solve this problem.

Further, in each slave of Patent Document 2, there is a problem that a time error occurs between the change in the reference position command and the change in rotational position due to variation in detection timing of the position change detector 220 . For example, when each slave receives and uses a reference position command from the master by serial communication, even if the reference position command is sent from the master every predetermined cycle Ts, the processing timing on the slave side may vary due to reception processing, interrupt processing, etc. Variation occurs. In other words, even if the master intends to transmit the reference position command at time t1, the slave side will detect the position change detector 220 at time t1+ΔT1 or detect it at time t1+ΔT2, and the actual position The deviation and the positional deviation of the slave do not match, and since the speed control is corrected accordingly, speed ripples and the like are generated due to variations in processing points. In this regard, according to the fifth or sixth aspect of the present invention, it is possible to detect the deviation time at the time of detection by the position change detector, and to correct the rotational position command and the position deviation according to the deviation time. , it is possible to solve this problem.

Moreover, if all the slaves 60 and 61 cannot normally receive the position command clear command from the master 1, there is a problem that normal synchronous operation cannot be performed. In this regard, according to the seventh aspect of the invention, it is possible to suppress the occurrence of this problem for the reason described above.

Also, if noise is mixed in the output of the motor origin sensor or the mechanical origin sensor, there is a problem that normal synchronous operation cannot be performed. In this regard, according to the eighth aspect of the invention, it is possible to suppress the occurrence of this problem for the reason described above.

In addition, since the rotational position of each slave machine operated synchronously is controlled so that the positional deviation from the rotational position command becomes 0, the machine with a very large positional deviation at the start of position control increases the rotational speed. It operates to minimize the positional deviation by changing. Therefore, there is a problem that the synchronous operation of the machines, in which problems occur due to a large change in the rotation speed, becomes difficult. In this respect, according to the inventions of claims 9 and 10, the speed correction by the position control can be small, and the transient state at the time of shifting to the position control can be suppressed to a minimum, so this problem can be solved. becomes possible. Japanese Patent Laying-Open No. 2008-125183 proposes clearing the reference position command output from the master with the output of the mechanical origin sensor of the machine. However, there is the problem of having to connect the output of the machine's machine origin sensor to the master. In this respect, according to the ninth or tenth aspect of the invention, when exchange of information between the master 1 and each slave is realized by two-way communication, the output of the mechanical origin sensor 223 is connected to the master 1. It is possible to solve this problem without having to

Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many modifications and substitutions may be made within the spirit and scope of the invention. Therefore, the present invention should not be construed as limited by the embodiments described above, and various modifications and changes are possible without departing from the scope of the claims. For example, it is possible to integrate a plurality of configuration blocks described in the configuration diagrams of the embodiments, or to divide one configuration block.

According to the present invention, the gear ratio of the physical gear between the motor of each slave and the machine can be set to any value, and the virtual gear can be set with any gear ratio between the reference machine and each slave machine. Therefore, absolute synchronous operation equivalent to connecting machines between slaves with virtual gears is possible, and application to various systems is possible. In addition, a low-precision mechanical origin sensor can be used without deteriorating the synchronization accuracy, and noise countermeasures for the motor origin sensor and the mechanical origin sensor can be taken with a simple process, resulting in a low cost system. Also, it can be applied to a machine whose rotational speed cannot be greatly changed at the start of position control.

1 master 10, 11 synchronous operation device 30, 33 control device 60, 61, 70, 71 slave 227 position controller 226, 250 adder 204 speed controller 205 torque controller 206 motor 207 machine 208 gear 211 position sensor 219 speed conversion device 220, 232 position change detector 222 motor origin sensor 223 mechanical origin sensor 224 initial position detector 225 mechanical rotation position calculator 228, 239 adder/subtractor 229 rotational position command calculator 230 position command change calculator 233 transmission/reception processor 234 communication cable 235 absolute mechanical rotation position change calculator 236, 237, 251 multiplier 238 accumulator 240 command completion flag calculator 241 synchronous position command change calculator 252 PLL (Phase Locked Loop)
261 speed command converter

Claims (10)

A synchronous operation device comprising a plurality of slaves,
Each of the slaves includes a machine, a motor that drives the machine, a position sensor that outputs a pulse with polarity in the direction of rotation according to the rotational position of the motor, and a predetermined position that is detected during one rotation of the motor. A motor origin sensor that outputs a pulse for determining a position, a mechanical origin sensor that outputs a pulse for determining a predetermined position in one rotation of the machine, and a control device that controls the motor. receiving a command clear command and a reference position command obtained by setting 0 when the position command clear command is ON and integrating the standard speed command of the reference machine when the position command clear command is OFF at predetermined intervals;
The control device is
a command completion flag calculator for outputting a command completion flag that is 0 until immediately before the position command clear command is turned ON immediately after the power is turned on and then becomes 1;
The position sensor, the motor origin sensor, and the mechanical origin sensor output an initial value Cn0 of the rotational position Cn of the machine and an origin completion flag that changes from 0 to 1 at the time the initial value Cn0 is output. an initial position detector;
When the position command clear command is ON, the rotational position command Pn is cleared. a rotational position command calculator to be updated;
a machine rotational position calculator that calculates and outputs the rotational position Cn of the machine by accumulating the output pulses of the position sensor with the Cn0 as an initial value when the origin completion flag is 1;
When the product of the command completion flag and the origin completion flag is 0, the rotation speed of the motor is controlled by a predetermined speed command, and when the product is 1, the rotation position Cn of the machine is controlled by the rotation position command Pn. A synchronizing device for controlling the motors to follow. A synchronous operation device comprising a plurality of slaves,
Each of the slaves includes a machine, a motor that drives the machine, a position sensor that outputs a pulse with polarity in the direction of rotation according to the rotational position of the motor, and a predetermined position that is detected during one rotation of the motor. A motor origin sensor that outputs a pulse for determining a position, a mechanical origin sensor that outputs a pulse for determining a predetermined position in one rotation of the machine, and a control device that controls the motor. receiving a command clear command and a reference position command obtained by setting 0 when the position command clear command is ON and integrating the standard speed command of the reference machine when the position command clear command is OFF at predetermined intervals;
The control device is
a command completion flag calculator for outputting a command completion flag that is 0 until immediately before the position command clear command is turned ON immediately after the power is turned on and then becomes 1;
The position sensor, the motor origin sensor, and the mechanical origin sensor output an initial value Cn0 of the rotational position Cn of the machine and an origin completion flag that changes from 0 to 1 at the time the initial value Cn0 is output. an initial position detector;
The command completion flag is sampled every predetermined period, and when the command completion flag is 0, it is set to 0, and when the command completion flag is 1, the variation ΔP0 of the reference position command between the predetermined cycles is used. a synchronous position command change amount calculator for outputting a value ΔPnx as the obtained position command change amount ΔPn;
The origin completion flag is sampled at each predetermined period, and when the origin completion flag is 0, it is set to 0, when the origin completion flag changes to 1, it is set to the rotational position Cn, and when the origin completion flag is 1 is an absolute mechanical rotational position change calculator that outputs a value ΔCnx as the number of output pulses ΔCn of the position sensor during the predetermined period;
setting the position deviation Pi immediately after power-on to 0, and updating the position deviation Pi by the difference ΔPi between the value ΔPnx and the value ΔCnx each time the reference position command is received;
When the product of the command completion flag and the origin completion flag is 0, the rotation speed of the motor is controlled by a predetermined speed command, and when the product is 1, the motor is operated so that the position deviation Pi becomes 0. Synchronous operation device to control. When the machine is driven by the motor with physical gears of gear ratio Da/Db,
Assuming that the machine is connected to the reference machine by a virtual gear having a gear ratio of Ea/Eb, the number of output pulses per rotation of the position sensor is Pmn, and the reference position command is given by one rotation of the reference machine. The irreducible fraction of (Db*Ea*Pmn)/(Da*Eb*Pm0) is defined as the total gear ratio An/Bn assuming that it changes by an integer in the range of 0 to Pm0-1, and the position command change amount ΔPn is obtained by using the change ΔP0 as ΔPn=(An*ΔP0+F)/Bn
is required by
3. The synchronous operation device according to claim 1, wherein said F is a remainder of division when obtaining the previous .DELTA.Pn. When the machine is driven by the motor with physical gears of gear ratio Da/Db,
The initial position detector,
When the gear ratio Da/Db is less than 1, the initial rotational position Cn is determined by measuring the number of output pulses from the position sensor between the pulse output of the mechanical origin sensor and the pulse output of the motor origin sensor. set the value and
When the gear ratio Da/Db exceeds 1, the initial rotation position Cn is determined by measuring the number of output pulses from the position sensor between the pulse output of the motor origin sensor and the pulse output of the mechanical origin sensor. set the value and
4. The synchronous operation device according to claim 1, wherein when the gear ratio Da/Db is 1, the initial value of the rotational position Cn is set according to the pulse output time of the motor origin sensor. The timing for receiving the reference position command is input, the variation time is obtained by PLL processing as the difference between the average point of the timing and the timing, the position command correction value is obtained according to the variation time, and the position 2. A synchronous operation device according to claim 1, wherein said rotational position command Pn is corrected with a command correction value. The timing for receiving the reference position command is input, the variation time is obtained by PLL processing as the difference between the average point of the timing and the timing, the position command correction value is obtained according to the variation time, and the position 3. The synchronous operation device according to claim 2, wherein the positional deviation Pi is corrected with a command correction value. When the position command clear command is on, the slave sets a position command clear signal and transmits it to the master, and clears the position command clear signal after a predetermined time has passed since the position command clear command is off. to the master,
The master continues to turn on the position command clear command until receiving the set position command clearing signals from all the slaves,
When the ON time of the position command clear command exceeds a predetermined value, or when the master receives the position command clearing signal which is set even though the ON of the position command clear command is not transmitted. 3. The synchronous operation device according to claim 1 or 2, which judges that there is an abnormality in the When the output pulse of the motor origin sensor or the mechanical origin sensor is a square wave, the initial position detector measures the output pulse of the position sensor between the rising edge or the falling edge of the square wave and the opposite edge thereof. 5. The synchronous operation device according to claim 2, wherein the number of pulses is measured, and when the measured value is within a predetermined range, the output pulse of the motor origin sensor or the mechanical origin sensor is determined to be valid. each of the slaves drives the motor based on the reference speed command received from the master;
The master receives, as a position deviation, the difference between the rotational position command Pn and the rotational position Cn from a predetermined one of the slaves when the position command clear command is in an ON state, and calculates the position deviation. 2. The synchronous operation device according to claim 1, wherein said position command clear command is turned off at the timing when the absolute value becomes minimum. each of the slaves drives the motor based on the reference speed command received from the master;
The master receives the positional deviation Pi from a predetermined one of the slaves while the positional command clear command is in an ON state, and outputs the positional command at the timing when the absolute value of the positional deviation Pi becomes the minimum. 3. The synchronous operation device according to claim 2, wherein the clear command is turned off.

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