JP2017060327A - Motor control device - Google Patents

Abstract

There is provided a motor control device capable of synchronously controlling three or more motors and capable of sufficiently reducing a synchronization error between the motors.
A motor control device according to the present invention drives and controls a first motor based on a command to the first motor, and compensates for a positional difference and a speed difference between the first motor and the second motor. The second motor is synchronized with the first motor.
[Selection] Figure 1

Description

  The present invention relates to a motor control device.

  Large chip mounters and large machine tools improve positional accuracy while preventing yawing from occurring in the movable part by driving one movable part with two motors. A large injection molding machine is miniaturized by driving one movable part with two motors.

  In the following Patent Document 1, ball screws are provided on both sides of an injection screw and driven by two motors, and these two motors are controlled synchronously.

  The following Patent Document 2 discloses a technique for compensating and synchronizing a speed difference between motors. In this document, the motor speed is synchronized by executing a process for compensating for the difference between the motor speed and other motor speeds for each motor.

  The following Patent Document 3 discloses a technique for compensating and synchronizing a positional difference between motors. In this document, a position correction value is obtained by multiplying the difference between the position feedback value of the main servo circuit and the position feedback value of each slave servo circuit by a gain, and a speed command is issued using this position correction value. The position is corrected.

JP-A-61-237615 JP 2005-269758 A Japanese Patent Laid-Open No. 11-305839

  Since the technique described in Patent Document 2 performs a process for compensating for a difference between other motor speeds for each motor, it is difficult to apply the technique to three or more motors. It is done. This is because when there are three or more motors, it is difficult to determine which motor should be used to compensate for the difference.

  Since the technique described in Patent Document 3 only compensates for the position difference, there is a possibility that the synchronization error between the motors cannot be made sufficiently small. Further, even if the position difference is compensated, there is a possibility that a speed difference may occur. Therefore, in the machine driven by the motor, torsional vibration due to the speed difference may occur.

  The present invention has been made in view of the above problems, and provides a motor control device capable of synchronously controlling three or more motors and sufficiently reducing synchronization errors between the motors. The purpose is to do.

  The motor control device according to the present invention drives and controls the first motor based on a command to the first motor, and compensates for the position difference and the speed difference between the first motor and the second motor to control the second motor. Synchronize with the first motor.

  According to the motor control device of the present invention, three or more motors can be accurately synchronized to suppress torsional vibration.

It is a control block diagram which shows the structure of the motor control apparatus 1000 which concerns on Embodiment 1. FIG. It is a control block diagram which shows the structure of the motor control apparatus 1000 which concerns on Embodiment 2. FIG. It is a control block diagram which shows the structure of the motor control apparatus 1000 which concerns on Embodiment 3. It is a control block diagram which shows the structure of the motor control apparatus 1000 which concerns on Embodiment 4. FIG. 10 is a control block diagram illustrating a configuration of a motor control device 1000 according to a fifth embodiment. FIG. 10 is a control block diagram illustrating a configuration of a motor control device 1000 according to a sixth embodiment. FIG. 10 is a control block diagram illustrating a configuration of a motor control device 1000 according to a seventh embodiment. FIG. 10 is a control block diagram illustrating a configuration of a motor control device 1000 according to an eighth embodiment. FIG. 10 is a control block diagram illustrating a configuration of a motor control device 1000 according to a ninth embodiment.

<Embodiment 1>
FIG. 1 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the first embodiment of the present invention. The motor control device 1000 according to the first embodiment is a device that controls driving of the first motor 410 and the second motor 430 that drive the machine 500 in synchronization. In FIG. 1, the control system for controlling the first motor 410 and the control system for controlling the second motor 430 are each surrounded by a dotted frame from the viewpoint of easy viewing. These control systems constitute a motor control unit. The operation of each controller provided in the motor control device 1000 will be described below.

  The first rotational position sensor 420 detects the rotational position (first position P1) of the first motor 410. The second rotational position sensor 440 detects the rotational position (second position P2) of the second motor 430. Examples of these sensors include an encoder, but are not limited thereto.

  The motor control device 1000 obtains the speed (first speed) V1 of the first motor 410 by differentiating the first position P1 with respect to time. This differentiation operation can be performed by an appropriate differentiator, for example. The same applies to other differential operations described below.

  The motor control device 1000 receives a position command for the first motor 410. The position controller 110 calculates a first speed command for the first motor 410 based on the difference between the position command and the position of the first motor 410 (first position P1). The first speed command is configured to compensate for a difference between the position command and the first position P1. The difference between the position command and the first position P1 is acquired using a subtracter. The same applies to other subtraction processing and addition processing described below.

  The speed controller 130 calculates a first torque command for the first motor 410 based on the difference between the first speed command and the first speed V1. The first torque command is configured to compensate for the difference between the first speed command and the first speed V1.

  The torque controller 160 drives the first motor 410 by controlling the torque of the first motor 410 according to the first torque command.

  The motor control device 1000 obtains the speed (second speed) V2 of the second motor 430 by differentiating the second position P2 with respect to time.

  The position compensator 220 compensates the difference between the position command (first position P1) for the second motor 430 and the second position P2 based on the difference between the first position P1 and the second position P2. The compensation value of is calculated. The motor control device 1000 calculates a second speed command for the second motor 430 by adding the compensation value output from the position compensator 220 and the first speed command value.

  The speed controller 230 calculates a torque command for the second motor 430 based on the difference between the second speed command and the second speed V2. The torque command is configured to compensate for the difference between the second speed command and the second speed V2.

  The speed compensator 240 calculates a torque compensation value for the second motor 430 based on the difference between the first speed V1 and the second speed V2. The torque compensation value is configured to compensate for the difference between the first speed V1 and the second speed V2.

  The motor control device 1000 calculates a second torque command for the second motor 430 by adding the torque command calculated by the speed controller 230 and the torque compensation value calculated by the speed compensator 240.

  The torque controller 260 drives the second motor 430 by controlling the torque of the second motor 430 in accordance with the second torque command.

  In the above configuration, the position compensator 220 controls the first position P1 and the second position P2 to be equal, and the speed compensator 240 controls the first speed V1 and the second speed V2 to be equal. Therefore, the error between the motors is controlled not only in the position but also in the speed dimension. Since the derivative of the motor position is the motor speed, each motor can be accurately synchronized, and the position error between the motors can be reduced. Further, since the speeds of the motors are synchronized with high accuracy, torsional vibration in the machine 500 can be suppressed.

<Embodiment 2>
FIG. 2 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the second embodiment of the present invention. In the second embodiment, the motor control device 1000 is a device that controls driving of the first motor 410, the second motor 430, and the third motor 450 that drive the machine 500 in synchronization. The third rotational position sensor 460 detects the rotational position (third position P3) of the third motor 450. The motor control apparatus 1000 according to the second embodiment has substantially the same configuration as that of the first embodiment except for the difference due to the number of motors being three, and therefore the difference will be mainly described below.

  The motor control device 1000 obtains the speed (third speed) V3 of the third motor 450 by differentiating the third position P3 with respect to time.

  The position compensator 320 compensates for the difference between the position command (first position P1) for the third motor 450 and the third position P3 based on the difference between the first position P1 and the third position P3. The compensation value of is calculated. The motor control device 1000 calculates a third speed command for the third motor 450 by adding the compensation value output from the position compensator 320 and the first speed command value.

  The speed controller 330 calculates a torque command for the third motor 450 based on the difference between the third speed command and the third speed V3. The torque command is configured to compensate for the difference between the third speed command and the third speed V3.

  The speed compensator 340 calculates a torque compensation value for the third motor 450 based on the difference between the first speed V1 and the third speed V3. The torque compensation value is configured to compensate for the difference between the first speed V1 and the third speed V3.

  The motor control device 1000 calculates a third torque command for the third motor 450 by adding the torque command calculated by the speed controller 330 and the torque compensation value calculated by the speed compensator 340.

  The torque controller 360 drives the third motor 450 by controlling the torque of the third motor 450 in accordance with the third torque command.

  In the above configuration, the position compensator 320 controls the first position P1 and the third position P3 to be equal, and the speed compensator 340 controls the first speed V1 and the third speed V3 to be equal. Accordingly, the third motor 450 can be accurately synchronized with the first motor 410 in the dimensions of position and speed. As a result, the third motor 450 can exhibit the same effects as those of the first embodiment.

<Embodiment 3>
FIG. 3 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the third embodiment of the present invention. In the third embodiment, the motor control apparatus 1000 includes a configuration for compensating for the acceleration difference in addition to the configuration described in the first embodiment. Since the other configuration is substantially the same as that of the first embodiment, the difference will be mainly described below.

  The motor control device 1000 obtains the acceleration (first acceleration) A1 of the first motor 410 by time-differentiating the first position P1 twice, and determines the second position of the second motor 430 by differentiating the second position P2 twice. An acceleration (second acceleration) A2 is obtained.

  The acceleration compensator 250 calculates a torque compensation value for compensating the torque command for the second motor 430 based on the difference between the first acceleration A1 and the second acceleration A2. This torque compensation value is configured to compensate for the difference between the first acceleration A1 and the second acceleration A2.

  The motor control device 1000 uses the torque compensation calculated by the acceleration compensator 250 for the torque command obtained by adding the torque command calculated by the speed controller 230 and the torque compensation value calculated by the speed compensator 240. The second torque command is calculated by further adding the values. The torque controller 260 controls the second motor 430 using the second torque command.

  In the third embodiment, since the acceleration difference between the first motor 410 and the second motor 430 is compensated, each motor can be synchronized in the dimension of acceleration. Since the differential of the position is the speed and the differential of the speed is the acceleration, each motor can be synchronized with high accuracy, and the position error between the motors can be further reduced. In addition, since the accelerations of the motors are synchronized with high accuracy, the torsional vibration in the machine 500 can be further suppressed.

<Embodiment 4>
FIG. 4 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the fourth embodiment of the present invention. In the fourth embodiment, the motor control device 1000 includes a position controller 210 in addition to the configuration described in the first embodiment, and uses a position command for the first motor 410 as a position command for the second motor 430. That is, each motor is controlled based on a position command common to each motor. Since the other configuration is substantially the same as that of the first embodiment, the difference will be mainly described below.

  The position controller 210 calculates a speed command for the second motor 430 based on the difference between the position command and the second position P2. The speed command is configured to compensate for the difference between the position command and the second position P2. The motor control device 1000 calculates a second speed command for the second motor 430 by adding the compensation value output from the position compensator 220 and the speed command value calculated by the position controller 210.

  Also in the fourth embodiment, as in the first embodiment, the error between the motors can be synchronized in the position and speed dimensions, so that the position error between the motors can be reduced.

<Embodiment 5>
FIG. 5 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the fifth embodiment of the present invention. In the fifth embodiment, the motor control device 1000 includes the acceleration compensator 250 described in the third embodiment in addition to the configuration described in the fourth embodiment, and further calculates the first acceleration A1 and the second acceleration A2. The acceleration compensator 250 can synchronize the error between the motors in the dimension of acceleration in addition to the dimension of the position and speed, so that the position error between the motors can be further reduced.

<Embodiment 6>
FIG. 6 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the sixth embodiment of the present invention. In the sixth embodiment, the motor control device 1000 does not include the position controller 110 described in the first embodiment. The motor control device 1000 receives a speed command for the first motor 410 instead of a position command for the first motor 410. Since the other configuration is substantially the same as that of the first embodiment, the difference will be mainly described below.

  The speed controller 130 uses the speed command received by the motor control device 1000 instead of the first speed command in the first embodiment. The motor control device 1000 calculates the second speed command by adding the received speed command and the compensation value output from the position compensator 220. Other configurations are the same as those of the first embodiment.

  Also in the sixth embodiment, as in the first embodiment, the error between the motors can be synchronized in the position and speed dimensions, so that the position error between the motors can be reduced.

<Embodiment 7>
FIG. 7 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the seventh embodiment of the present invention. In the seventh embodiment, the motor control device 1000 includes the acceleration compensator 250 described in the third embodiment in addition to the configuration described in the sixth embodiment, and further calculates the first acceleration A1 and the second acceleration A2. The acceleration compensator 250 can synchronize the error between the motors in the dimension of acceleration in addition to the dimension of the position and speed, so that the position error between the motors can be further reduced.

<Eighth embodiment>
FIG. 8 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the eighth embodiment of the present invention. In the eighth embodiment, the motor control device 1000 does not include the position controller 110, the speed controller 130, and the speed controller 230 described in the first embodiment. Further, the motor control device 1000 receives a torque command for the first motor 410 instead of a position command for the first motor 410. Since the other configuration is substantially the same as that of the first embodiment, the difference will be mainly described below.

  The position compensator 220 compensates the difference between the position command (first position P1) for the second motor 430 and the second position P2 based on the difference between the first position P1 and the second position P2. The torque compensation value is calculated.

  The motor control device 1000 adds the torque compensation value output from the position compensator 220 and the torque compensation value calculated by the speed compensator 240. The motor control apparatus 1000 calculates the second torque command for the second motor 430 by further adding the torque command of the first motor 410 to the value after the addition. Thereby, each motor is controlled in accordance with a common torque command.

  In the eighth embodiment, as in the first embodiment, the error between the motors can be synchronized in the dimension of position and speed, so that the position error between the motors can be reduced.

<Embodiment 9>
FIG. 9 is a control block diagram showing the configuration of the motor control apparatus 1000 according to the ninth embodiment of the present invention. In the ninth embodiment, the motor control apparatus 1000 includes the acceleration compensator 250 described in the third embodiment in addition to the configuration described in the eighth embodiment, and further calculates the first acceleration A1 and the second acceleration A2.

  The motor controller 1000 uses the torque compensation value output from the position compensator 220, the torque compensation value calculated by the speed compensator 240, and the torque compensation value calculated by the acceleration compensator 250 in response to the torque command of the first motor 410. By adding, the second torque command is calculated.

  The acceleration compensator 250 can synchronize the error between the motors in the dimension of acceleration in addition to the dimension of the position and speed, so that the position error between the motors can be further reduced.

<Modification of the present invention>
The present invention is not limited to the embodiments described above, and includes various modifications. The above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to the one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Each of the above configurations (each controller, compensator, adder, subtractor, differentiator, etc.) can be configured using hardware such as a circuit device that implements the function, or software that implements the function. Can also be configured by executing an arithmetic device such as a CPU (Central Processing Unit).

  The position controller and the position compensator described in the above first to ninth embodiments can be configured by, for example, a proportional controller. The speed controller and the speed compensator can be constituted by, for example, a proportional integration controller. Any other suitable controller may be used as long as the difference can be compensated appropriately.

  In the third to ninth embodiments, three or more motors can be synchronously controlled and the position and speed of each motor can be synchronized by the same method as in the second embodiment. Specifically, (a) a command value for the first motor 410 is also used as a command value for another motor, and (b) a compensation value for compensating for a position difference, a speed difference, and an acceleration difference is added to the command value. do it.

  110: Position controller, 130: Speed controller, 160: Torque controller, 210: Position controller, 220: Position compensator, 230: Speed controller, 240: Speed compensator, 250: Acceleration compensator, 260: Torque controller, 1000: motor controller.

Claims (10)

A motor control unit for controlling the first and second motors such that the first motor and the second motor are synchronized with each other;
The motor control unit controls the first motor based on a position command for the position of the first motor, a speed command for the speed of the first motor, or a torque command for the torque of the first motor;
The motor control unit compensates for the difference between the position of the first motor and the position of the second motor and compensates for the difference between the speed of the first motor and the speed of the second motor. By controlling the second motor, the position and speed of the first motor and the position and speed of the second motor are synchronized. The motor control unit compensates for the difference between the acceleration of the first motor and the acceleration of the second motor and then controls the second motor to thereby control the acceleration of the first motor and the second motor. The motor control device according to claim 1, wherein accelerations of the motor are synchronized. The motor controller is
A first position controller that calculates a first speed command for the first motor based on a difference between the position command and the position of the first motor;
A first speed controller that calculates a first torque command for the first motor based on a difference between the first speed command and the speed of the first motor;
A position compensator for calculating a position compensation command for compensating for a difference between the position of the first motor and the position of the second motor;
A speed command adder that calculates a second speed command for the second motor by adding the first speed command and the position compensation command;
A second speed controller for calculating a second torque command for the second motor based on a difference between the speed of the second motor and the second speed command;
A speed compensator for calculating a speed compensation command for compensating for a difference between the speed of the first motor and the speed of the second motor;
A torque command adder that compensates the second torque command by adding the second torque command and the speed compensation command;
The motor control device according to claim 1, further comprising: The motor controller is
An acceleration compensator for calculating an acceleration compensation command for compensating for a difference between the acceleration of the first motor and the acceleration of the second motor;
A second torque command summer that further compensates the second torque command by adding the acceleration compensation command to the second torque command compensated by the torque command summer;
The motor control device according to claim 3, further comprising: The motor controller is
A first position controller that calculates a first speed command for the first motor based on a difference between the position command and the position of the first motor;
A first speed controller that calculates a first torque command for the first motor based on a difference between the first speed command and the speed of the first motor;
A second position controller that calculates a second speed command for the second motor based on the difference between the position command and the position of the second motor;
A position compensator for calculating a position compensation command for compensating for a difference between the position of the first motor and the position of the second motor;
A speed command adder that compensates the second speed command by adding the second speed command and the position compensation command;
A second speed controller for calculating a second torque command for the second motor based on the difference between the speed of the second motor and the output of the speed command summer;
A speed compensator for calculating a speed compensation command for compensating for a difference between the speed of the first motor and the speed of the second motor;
A torque command adder that compensates the second torque command by adding the second torque command and the speed compensation command;
The motor control device according to claim 1, further comprising: The motor controller is
An acceleration compensator for calculating an acceleration compensation command for compensating for a difference between the acceleration of the first motor and the acceleration of the second motor;
A second torque command summer that further compensates the second torque command by adding the acceleration compensation command to the second torque command compensated by the torque command summer;
The motor control device according to claim 5, further comprising: The motor controller is
A first speed controller for calculating a first torque command for the first motor based on a difference between the speed command and the speed of the first motor;
A position compensator for calculating a position compensation command for compensating for a difference between the position of the first motor and the position of the second motor;
A speed command adder that calculates a second speed command for the second motor by adding the speed command and the position compensation command;
A second speed controller for calculating a second torque command for the second motor based on a difference between the speed of the second motor and the second speed command;
A speed compensator for calculating a speed compensation command for compensating for a difference between the speed of the first motor and the speed of the second motor;
A torque command adder that compensates the second torque command by adding the second torque command and the speed compensation command;
The motor control device according to claim 1, further comprising: The motor controller is
An acceleration compensator for calculating an acceleration compensation command for compensating for a difference between the acceleration of the first motor and the acceleration of the second motor;
A second torque command summer that further compensates the second torque command by adding the acceleration compensation command to the second torque command compensated by the torque command summer;
The motor control device according to claim 7, further comprising: The motor controller is
A position compensator for calculating a position compensation command for compensating for a difference between the position of the first motor and the position of the second motor;
A speed compensator for calculating a speed compensation command for compensating for a difference between the speed of the first motor and the speed of the second motor;
A torque command adder that calculates a second torque command for the second motor by adding the torque command, the position compensation command, and the speed compensation command;
The motor control device according to claim 1, further comprising: The motor controller is
An acceleration compensator for calculating an acceleration compensation command for compensating for a difference between the acceleration of the first motor and the acceleration of the second motor;
A second torque command summer that further compensates the second torque command by adding the acceleration compensation command to the second torque command compensated by the torque command summer;
The motor control device according to claim 9, further comprising:

Images