JP6391489B2 - Motor control device - Google Patents

Description

  The present invention relates to a motor control apparatus capable of positioning a movable part at high speed and high accuracy by a plurality of motors jointly driving one movable part.

In a component mounter such as a mounter device, the number of component mounts per unit time can be increased by driving the movable part at high speed by a motor and positioning with high accuracy. Thereby, the manufacturing cost by component mounting work can be reduced.
For example, in a large mounter apparatus using a large table on which a large number of printed boards can be mounted simultaneously, it is conceivable that the single movable part is driven at a high speed by a plurality of motors.

For example, the motor control device disclosed in Patent Document 1 drives one movable part with two motors. Each of the two motors is controlled by a motor control model and a servo controller provided in correspondence with each other. The servo controller actually controls the movement of the motor based on the external position command. The motor control model has an element model corresponding to each element of the servo controller, and generates a model torque, a model speed, and a model position based on an external position command. Further, the difference between the model information and the control torque, control speed, and control position in the actual control fed back from the servo controller is calculated, and the difference is returned to the servo controller at a constant rate. Thus, by calculating the control error of the servo controller in the motor control model and returning the control error to the servo controller, the servo controller follows the model torque, model speed, and model position generated by the motor control model. The movement of the motor can be controlled.
As described above, the motor control device of Patent Document 1 suppresses the deviation between the control of the model and the servo controller by detecting the error between the motor control model and the servo controller as a disturbance and performing phase compensation on the error. By using the same model for the motor control system, it is considered that deviation between shafts (synchronization error) can be suppressed.
Unlike Patent Document 1, when one movable part is driven by a single motor, yawing may occur such that the movable part is inclined with respect to the driving direction of the motor. It can be expected that this yawing can be suppressed by driving two movable parts with two motors.

JP 2003-345442 A

However, in the method of Patent Document 1, unless the control response of the servo controller is sufficiently high, the control error between the model and the servo controller cannot be sufficiently suppressed. If the control error cannot be sufficiently suppressed in the control system of each motor, the synchronization accuracy among the plurality of motors cannot be ensured.
On the other hand, in an actual mechanical system, a ball screw or the like that drives a movable part with respect to a plurality of motors may be torsionally vibrated, or a machine base to which a plurality of motors and movable parts are attached may be vibrated by driving. For this reason, the control response of the servo controller for each axis cannot be made sufficiently high.
For this reason, in the method of Patent Document 1, when the control response of the servo controller cannot be sufficiently increased, it is not possible to ensure the accuracy of synchronization among a plurality of motors.

  The present invention has been made in order to solve such a problem, and its purpose is in a case where the control response of the feedback control system cannot be sufficiently enhanced in a machine in which one movable part is driven by a plurality of motors. Even so, it is an object to provide a motor control device that can improve the follow-up performance with respect to a command, further ensure synchronization accuracy among a plurality of motors, and as a result, realize high-speed and high-precision positioning. .

  A motor control device according to the present invention is a motor control device that drives one movable part jointly by N (N: a natural number of 2 or more) motors driven based on a common external position command. A model control system including a movable part model corresponding to the movement of the movable part driven by the motor, and generating a model command including a model position command from an external position command, and a pair of N motors N feedback control systems that are provided in correspondence with each other and feedback-control each motor based on a model command, and (N-1) feedback control systems are used for controlling each motor. The control error is compensated by the difference from the control error in the remaining one feedback control system.

In the present invention, each of the N feedback control systems feedback-controls each motor based on a model command including a model position instead of an external position command. In addition, since the model control system that generates the model command including the model position command from the external position command includes the movable part model corresponding to the movement of the movable part driven by the motor, the N feedback control systems are the models. Stable feedback control following the above is executed independently of each other, and the N motors can be controlled to follow the external position command in the same manner.
Moreover, in the present invention, the (N−1) feedback control systems compensate the control error in each by the difference from the control error in the remaining one feedback control system. The (N-1) feedback control systems execute each feedback control while synchronizing each control error so as not to cause a deviation from the control error of one feedback control system. That is, the N feedback control systems that execute control of the N motors independently of each other are controlled independently of each other, while one feedback control system and (N−1) feedback control systems It is possible to compensate for a control error shift that may occur between the two. A shift in control error that may occur between these N feedback control systems can be compensated between the N feedback control systems.
Therefore, in the present invention, for example, in a mechanical system from a plurality of motors to a movable part, even if a frictional force difference occurs between a plurality of ball screws that connect each of the plurality of motors to the movable part, for example, It is possible to compensate and suppress the synchronization error due to the force difference.
Moreover, in the present invention, even when the control responses of the plurality of feedback control systems are not high or cannot be improved, the followability to the command can be improved, and synchronization accuracy between the plurality of motors can be secured, As a result, high-speed and high-precision positioning can be realized.

FIG. 1 is a block diagram of a motor control device according to a first embodiment of the present invention. FIG. 2 is a block diagram of a motor control device according to the second embodiment of the present invention. FIG. 3 is a block diagram of a motor control device according to the third embodiment of the present invention. FIG. 4 is a block diagram of a motor control device according to the fourth embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a block diagram of a motor control device 1 according to the first embodiment of the present invention.
The motor control device 1 of FIG. 1 is one in which two motors of a first motor 2 and a second motor 3 jointly drive one movable part and can position the movable part at high speed and high accuracy.

The motor control device 1 in FIG. 1 includes a first model control system 10 that receives an external position command indicating a control position of a table 4 as a movable portion and generates various first model commands, and a first motor 2. A first feedback control system 30 that actually controls the first motor 2 based on the first model command with a feedback loop, and the same external position command as that of the first model control system 10 is input and various second models. A second model control system 50 that supplies a command; and a second feedback control system 70 that has a feedback loop including the second motor 3 and actually controls the second motor 3 based on the second model command. .
In the present embodiment, the first model command is a first model position command, a first model speed command, and a first model torque command. The second model command is a second model position command, a second model speed command, and a second model torque command.

The first feedback control system 30 includes a first control position error generator 31, a first synchronization position error generator 32, a first position synchronization compensator 33, a first synchronization compensation position error generator 34, and a first position controller 35. A first detection speed generator 36, a first control speed error generator 37, a first speed controller 38, a first control torque generator 39, a first torque command low-pass filter 40, and a first torque controller 41. .
The first control position error generator 31, the first synchronization compensation position error generator 34, the first position controller 35, the first control speed error generator 37, the first speed controller 38, and the first control torque generator 39, the first torque command low-pass filter 40, the first torque controller 41, the first motor 2, and the first sensor 42 constitute a feedback loop that actually controls the first motor 2.

The first motor 2 is, for example, a synchronous motor.
The first sensor 42 detects the rotational position of the first motor 2. The first sensor 42 is a rotary encoder attached to the rotor shaft of the first motor 2, for example. The rotary encoder outputs a pulse signal corresponding to the position of the rotor shaft of the motor. The pulse signal can be converted into the rotational position of the first motor 2 and the position of the table 4 as a movable part.

The first control position error generator 31 calculates these position errors based on the first model position command supplied from the first model control system 10 and the first detection position of the table 4 obtained from the first sensor 42. The first control position error shown is generated. The first control position error may be, for example, a value obtained by subtracting the first detection position from the first model position command.
Based on its own first control position error and a second control position error 71 generated by a second control position error generator 71, which will be described later, the first synchronization position error generator 32 (the difference between these control position errors ( A first synchronization position error indicating a synchronization error) is generated. The first synchronization position error may be, for example, a value obtained by subtracting another second control position error from its own first control position error. In this case, the synchronization error of the first feedback control system 30 with respect to the second feedback control system 70 is obtained.
The first position synchronization compensator 33 generates a first position synchronization error compensation amount from the first synchronization position error. In the present embodiment, for example, a proportional controller or a proportional-integral controller may be used as the first position synchronization compensator 33.
The first synchronization compensation position error generator 34 compensates for a first control position error that is a control position error in the first feedback control system 30 and a first position synchronization error that is a synchronization position error between two feedback control systems. The first control position error after the synchronization compensation process is generated based on the amount. The first control position error after the synchronization compensation process may be, for example, a total value obtained by adding the first control position error and the first position synchronization error compensation amount.
The first position controller 35 generates a first control speed from the first control position error after the synchronization compensation process. The first position controller 35 has a first control speed corresponding to the control position error in the first feedback control system 30 and the synchronous position error of the first feedback control system 30 with the second feedback control system 70 as a reference. Generate. When the control position of the first feedback control system 30 is delayed as compared with the control position of the second feedback control system 70, the first control speed is increased.

The first detection speed generator 36 generates the first detection speed of the table 4 from the rotational position detected by the first sensor 42.
The first control speed error generator 37 generates a first control speed error based on the first control speed, the first detected speed, and the first model speed command. The first control speed error may be obtained by adding the first model speed command to the control speed error obtained by subtracting the first detection speed from the first control speed, for example.
The first speed controller 38 generates a first control torque from the first control speed error. The first speed controller 38 generates a first control torque according to the control speed error in the first feedback control system 30 and the first model speed command. When at least one of the control speed error and the first model speed command increases, the first control torque increases.

The first control torque generator 39 generates a first total control torque based on the first control torque and the first model torque command. The first total control torque may be, for example, the sum of the first control torque and the first model torque command.
The first torque command low-pass filter 40 performs a low-pass filter process on the first total control torque. By this low pass filter process, the high frequency component can be removed from the first total control torque. As such a high frequency component, for example, there is a quantized ripple component at a position by the first sensor 42.
The first torque controller 41 controls the first motor 2 based on the first total control torque after the low pass filter process.

By such feedback control closed by the first feedback control system 30, the first feedback control system 30 causes the first model position command, the first model speed command, and the first model torque output from the first model control system 10. The first motor 2 is rotationally driven according to the command. The table 4 is driven according to the rotation of the first motor 2.
If an error occurs in the control position or the control speed in the first feedback control system 30, or if the control position of the first feedback control system 30 is deviated from the control position of the second feedback control system 70, these errors and The drive torque of the first motor 2 increases or decreases so as to suppress the deviation.
Thus, the mechanical system from the first motor 2 to the table 4 is controlled to move to the position of the first model position command by movement according to the first model torque command and the first model speed command.

The first model control system 10 receives an external position command, calculates a virtual operation of the first feedback control system 30 using a model corresponding to the first feedback control system 30, and sends the first feedback control system 30 to the first feedback control system 30. A first model command to be given is generated.
The first model position command is a command indicating the control position of the table 4.
The first model speed command is a command indicating the control speed of the table 4 being driven.
The first model torque command is a command indicating the control torque of the table 4 being driven.
Then, the first model control system 10 of the present embodiment calculates a first model position error calculator 11, a first model position controller 12, a first model speed calculation in order to calculate the operation of the first feedback control system 30. 13, a first model speed error calculator 14, a first model speed controller 15, a first model torque command low pass filter 16, and a first movable part model 17.
The first model position error calculator 11, the first model position controller 12, the first model speed error calculator 14, the first model speed controller 15, the first model torque command low-pass filter 16, and the first movable part The model 17 constitutes a feedback loop closed by the first model control system 10. The feedback loop of the first model control system 10 corresponds to the feedback loop of the first feedback control system 30.

The first model position error calculator 11 calculates a first model position error using a model corresponding to the first control position error generator 31. The first model position error calculator 11 subtracts the first model position output from the first movable part model 17 from the external position command to calculate the first model position error.
The first model position controller 12 calculates a first model speed using a model corresponding to the first position controller 35. The first model position controller 12 calculates a first model speed from the first model position error.
The first model speed calculator 13 calculates the first model detected speed using a model corresponding to the first detected speed generator 36. The first model speed calculator 13 calculates the first model detection speed from the first model position. The first model detection speed is output to the first feedback control system 30 as a first model speed command.
The first model speed error calculator 14 calculates a first model speed error using a model corresponding to the first control speed error generator 37. The first model speed error calculator 14 subtracts the first model detection speed from the first model speed to calculate a first model speed error.
The first model speed controller 15 calculates a first model torque using a model corresponding to the first speed controller 38. The first model speed controller 15 calculates a first model torque from the first model speed error. The first model torque is output to the first feedback control system 30 as a first model torque command.
The first model torque command low-pass filter 16 performs filter calculation using a model corresponding to the first torque command low-pass filter 40. The first model torque command low pass filter 16 performs low pass filter processing on the first model torque.
The first movable part model 17 calculates the first model position based on the movable part model corresponding to the movement of the mechanical system from the first motor 2 to the table 4. Here, as the movable part model corresponding to the mechanical system from the first motor 2 and the first ball screw 5 to the table 4, a rigid body model in which no deviation occurs between them is used. The first movable part model 17 calculates the first model position from the first model torque after the low-pass filter processing. The first model position is output to the first feedback control system 30 as a first model position command.

By such feedback control corresponding to the first feedback control system 30, the first model control system 10 causes the first model position command, the first model speed command, and the first model torque command when the movable part is regarded as a rigid body. Is generated.
Control parameters for enabling desired positioning control in the table 4 may be set in each element of the first model control system 10.
For example, the first feedback control system 30 adjusts the parameters so as to obtain a stable gain that does not cause vibration in the mechanical system. Then, the first model control system 10 sets a position gain that is slightly higher than the position gain of the first feedback control system 30. By setting the parameters in this way, the machine can be driven at high speed without causing vibration in the mechanical system.

The second feedback control system 70 includes a second control position error generator 71, a second position controller 75, a second detection speed generator 76, a second control speed error generator 77, a second speed controller 78, and a second speed controller 78. A control torque generator 79, a second torque command low-pass filter 80, and a second torque controller 81 are included.
A second control position error generator 71, a second position controller 75, a second control speed error generator 77, a second speed controller 78, a second control torque generator 79, a second torque command low pass filter 80, The second torque controller 81, the second motor 3, and the second sensor 82 constitute a feedback loop that actually controls the second motor 3.
Each component of the second feedback control system 70 is the same as the component of the same name having a different number in the first feedback control system 30, and detailed description thereof is omitted. However, the second position controller 75 generates the second control speed from the second control position error generated by the second control position error generator 71. A second control speed is generated based on a second control position error that has not been subjected to synchronization compensation processing.
The second model control system 50 includes a second model position error calculator 51, a second model position controller 52, a second model speed calculator 53, a second model speed error calculator 54, a second model speed controller 55, A second model torque command low-pass filter 56 and a second movable part model 57 are included. Each component of the second model control system 50 is the same as the component having the same name in the first model control system 10, and detailed description thereof is omitted. The same value as that of the first model control system 10 is set to the parameter of each part of the second model control system 50.
In the following description, various signal names in the second feedback control system 70 and the second model control system 50 include various signal names in the corresponding first feedback control system 30 and first model control system 10. Is used in which the number is changed from the first to the second.

In the motor control device 1 of FIG. 1, the first sensor 42 may be configured integrally with the first motor 2. The components of the first feedback control system 30 other than the first motor 2 and the first sensor 42 and the first model control system 10 are connected to the first motor 2 and the first sensor 42 by a first cable. It may be realized in a first computer device in one motor control device. In this case, each component of the first feedback control system 30 executes each process by a calculation process, and can suitably correspond to the calculation process of each part of the first model control system 10.
Similarly, the second sensor 82 may be configured integrally with the second motor 3. The components of the second feedback control system 70 other than the second motor 3 and the second sensor 82 and the second model control system 50 are connected to the second motor 3 and the second sensor 82 by a second cable. It may be realized in a second computer device in a two-motor control device. In this case, each component of the second feedback control system 70 executes each process by a calculation process, and can suitably correspond to the calculation process of each part of the second model control system 50.
Further, when the first motor control device and the second motor control device are used in this way, the first motor control device and the second motor control device are connected by a communication cable, and the first motor control device is controlled from the second motor control device. A second control position error needs to be transmitted to the device.
In addition, for example, the first computer device and the second computer device may be provided in a single motor control device.
Moreover, components other than the 1st motor 2, the 1st sensor 42, the 2nd motor 3, and the 2nd sensor 82 in FIG. 1 may be implement | achieved in the single computer apparatus in a single motor control apparatus. . In this case, the second control position error can be transmitted, for example, by inter-program communication.
Further, the first model control system 10 and the second model control system 50 are made one model control system, and a common model command is transmitted from the single model control system to the first feedback control system 30 and the second feedback control system 70. May be supplied.

  Next, the operation of the motor control device 1 in FIG. 1 will be described.

  In order to control the position of the table 4, a common external position command is simultaneously supplied from the host controller to the first model control system 10 and the second model control system 50.

  The first model control system 10 supplied with the external position command subtracts the first model position from the external position command, and calculates the first model speed from the first model position error. Further, the first model detected speed is subtracted from the first model speed, and the first model torque is calculated from the first model speed error. Further, the first model position is calculated from the first model torque after the low-pass filter processing. Further, the first model detection speed is calculated from the first model position. Through this series of arithmetic processing, the first model control system 10 generates a first model position command, a first model speed command, and a first model torque command as the first model command and outputs the first model position command, the first model speed command, and the first model torque command to the first feedback control system 30. .

The first feedback control system 30 to which the first model command is supplied generates a first control position error indicating a position error between the first model position command and the first detection position of the table 4 obtained from the first sensor 42. .
The first feedback control system 30 also includes a first synchronization indicating a position error difference (synchronization error) between the first control position error of the first feedback control system 30 and the second control position error generated by the second control position error generator 71. A position error is generated, and a first position synchronization error compensation amount is generated. Further, the first control position error after the synchronization compensation processing is generated from the first control position error and the first position synchronization error compensation amount, and the first control speed is generated.
Further, the first feedback control system 30 generates a first control speed error from the first control speed, the first detected speed, and the first model speed command, and generates a first control torque.
The first feedback control system 30 generates a first total control torque from the first control torque and the first model torque command, and performs a low pass filter process. Then, the first torque controller 41 controls the first motor 2 based on the first total control torque after the low pass filter process. The first sensor 42 detects the rotational position of the first motor 2. The first detection speed generator 36 generates a first detection speed from the rotational position detected by the first sensor 42.

  The second model control system 50 to which the same external position command is supplied simultaneously with the first model control system 10 performs the same feedback control as the first model control system 10 described above. The second feedback control system 70 to which the second model command is supplied from the second model control system 50 also executes the same feedback control as the first feedback control system 30 described above.

In the present embodiment, the first model control system 10 and the second model control system 50 are configured by the same feedback loop including a movable part model in which the mechanical system from the motor to the table 4 is regarded as a rigid body, and at the same time. The model command is calculated based only on the input common external position command. For this reason, the first model control system 10 and the second model control system 50 can simultaneously calculate and output the same model command based on the same external position command while separately performing model calculations independently of each other. For example, the first model torque command and the second model torque command can be the same value.
In this embodiment, the feedback control system includes a control position error generator, a position controller, a control speed error generator, a speed controller, a control torque generator, a torque command low pass filter, a torque controller, a motor, and a sensor. The model control system is fed back by the model position error calculator, model position controller, model speed calculator, model speed error calculator, model speed controller, model torque command low pass filter, and moving part model. A loop is configured. The model control system can be suitably associated with the feedback control system.
Therefore, the first motor 2 and the second motor 3 are simultaneously driven in the same manner based on the same model torque command. The first motor 2 and the second motor 3 can drive the table 4 at high speed while being synchronized with each other. As a result, even if the control loop responses of the first feedback control system 30 and the second feedback control system 70 remain low, two-axis simultaneous drive by the first motor 2 and the second motor 3 synchronized with each other can be realized, and the table 4 can be operated at high speed Can be driven.
For this reason, unlike the present embodiment, when the table 4 is driven by a single motor, the table 4 may cause yawing in which the table 4 is inclined with respect to the axial direction of the drive shaft. In this embodiment, two motors are used. And the table 4 are connected to each other by two ball screws provided side by side with respect to the table 4, and the two motors drive the table 4 in synchronization with each other, so that yawing can be suitably suppressed.

In addition, in the present embodiment, the first feedback control system 30 not only executes the feedback control following the same model command as the second feedback control system 70 but also the control position error with the second feedback control system 70. Feedback control is executed so as to compensate for the deviation. The first feedback control system 30 calculates a difference from the control position error of the second feedback control system 70 by the first synchronization position error generator 32, and a first position that compensates the difference by the first position synchronization compensator 33. A synchronization error compensation amount is calculated, and a first control position error after synchronization compensation processing is generated by the first synchronization compensation position error generator 34. Therefore, the shift between the position errors between the two axes of the first feedback control system 30 and the second feedback control system 70 can be compensated between the first feedback control system 30 and the second feedback control system 70. In particular, by using a proportional-plus-integral controller as the first position synchronization compensator 33, the deviation can be prevented from occurring steadily.
For this reason, the first feedback control system 30 and the second feedback control system 70 are made to follow the same rigid model as in the present embodiment, and the synchronous control is performed so that the control deviation between the axes hardly occurs. It is possible to effectively suppress synchronization errors that may occur. For example, in the rigid body model, the synchronization error due to the difference in frictional force between ball screws that may occur in the mechanical system is not considered and cannot be suppressed by control. Can be effectively suppressed.

  As described above, in this embodiment, each model control system is configured using a rigid body model in a machine in which one movable part is driven by a plurality of (here, two) motors, and the actual model is made to follow the model. By causing the feedback control system to execute control, it is possible to improve the followability to the position command even when the feedback response of the control system that controls the individual motors cannot be enhanced. Further, since the position error between the axes is compensated between a plurality of (here, two) feedback control systems, it is possible to effectively suppress the synchronization error due to the difference in frictional force. And even if the control response of each feedback control system is not high, the position error between the axes can be effectively reduced to increase the synchronization accuracy.

In the present embodiment, the model control system is not affected by the movement of the feedback control system.
Therefore, the plurality of model positions output from the plurality of model control systems have the same value (command). The plurality of feedback control systems can similarly control each motor based on the model position based on the same value (command).
The model control system can be common to a plurality of feedback control systems, for example.

  As described above, in the present embodiment, two feedback controls are performed by performing model follow-up control with the same rigid body model for the two motors that move the movable part together in a common external position command. The torque command given to the system can be made the same for all axes, so that even if the control response of the feedback control system is not high, it is difficult to cause a deviation between the control errors of multiple feedback control systems. Can be executed. In addition, a slight deviation in control error that may occur between the two feedback control systems is compensated between the two feedback control systems. Therefore, even if a control error shift occurs between the two feedback control systems that execute the control because the synchronization error hardly occurs, it can be suppressed. The control system of the two motors synchronizes the two motors in the case where one movable part is controlled by two motors by the control in which the control that hardly causes the synchronization deviation and the control that suppresses the synchronization deviation is duplicated. Accuracy can be increased.

The above embodiment is an example in which two sets of model control system and feedback control system are used in order to drive the movable part with two motors. In addition, the synchronization position error generator, the position synchronization compensator, and the synchronization compensation position error generator are applied to the first feedback control system.
In addition, the synchronization position error generator, the position synchronization compensator, and the synchronization compensation position error generator may be applied to the second feedback control system.
In addition, the movable part may be driven by three or more motors. In this case, the model control system and the feedback control system may basically be provided in the same number of sets as the motor. When N (N is a natural number of 2 or more) motors are used, the synchronization position error generator, the position synchronization compensator, and the synchronization compensation position error generator are added to (N−1) feedback control systems. What is necessary is just to provide. In the (N−1) feedback control systems, the (N−1) synchronization position error generators may generate a position synchronization error with the control position error of the remaining one feedback control system. .

[Second Embodiment]
FIG. 2 is a block diagram of the motor control device 1 according to the second embodiment of the present invention.
In the motor control device 1 of FIG. 2, the second feedback control system 70 includes a second synchronization position error generator 72, a second position synchronization compensator 73, and a second synchronization compensation position error generator as compared with the motor control device 1 of FIG. 1. It differs in having 74.
The second synchronization position error generator 72, the second position synchronization compensator 73, and the second synchronization compensation position error generator 74 are the first synchronization position error generator 32, the first position synchronization compensator 33, and the first synchronization. Corresponding to the compensation position error generator 34.
Based on the second control position error of its own and the first control position error generated by the first control position error generator 31, the second synchronization position error generator 72 generates a difference (synchronization error) between these control position errors. ) To generate a second synchronization position error. The second synchronization position error may be, for example, a value obtained by subtracting another first control position error from its own second control position error. In this case, the synchronization error of the second feedback control system 70 with respect to the first feedback control system 30 is obtained.
The second position synchronization compensator 73 generates a second position synchronization error compensation amount from the second synchronization position error. In the present embodiment, since compensation is applied between the first feedback control system 30 and the second feedback control system 70, the first position synchronization compensator 33 and the second position synchronization compensator 73 are proportionally controlled. Use a vessel.
The second synchronization compensation position error generator 74 compensates for a second control position error that is a control position error in the second feedback control system 70 and a synchronization position error between the two feedback control systems. The second control position error after the synchronization compensation process is generated based on the amount. The second control position error after the synchronization compensation process may be, for example, a total value obtained by adding the second control position error and the second position synchronization error compensation amount.
The second position controller 75 generates a second control speed from the second control position error after the synchronization compensation process. The second position controller 75 has a second control speed corresponding to the control position error in the second feedback control system 70 and the synchronization position error of the second feedback control system 70 with the first feedback control system 30 as a reference. Generate. When the control position of the second feedback control system 70 is delayed as compared with the control position of the first feedback control system 30, the second control speed increases.
The other configuration and operation of the motor control device 1 of FIG. 2 are the same as those of FIG.

In the present embodiment, the first feedback control system 30 and the second feedback control system 70 can compensate for the position error between the two axes between the two feedback control systems. As a result, even if the control response of each feedback control system is not high, the position error between the axes can be reduced and the synchronization accuracy can be increased. Higher synchronization accuracy can be expected than in the first embodiment.
For this reason, for example, by causing the first feedback control system 30 and the second feedback control system 70 to follow the same rigid body model, it is difficult to generate a synchronization error. Even if a synchronization position error due to a force difference or the like may occur, the errors between the shafts due to a difference in the frictional force of the mechanical system are more effectively suppressed than the first embodiment. Can do.
As described above, in this embodiment, each model control system is configured using a rigid body model in a machine in which one movable part is driven by a plurality of (here, two) motors, and the actual model is made to follow the model. By causing the feedback control system to execute control, it is possible to improve the followability to the position command even when the feedback response of the control system that controls the individual motors cannot be enhanced. Further, since the position error between the axes is mutually compensated between the two feedback control systems, even if the control response of each feedback control system is not high, the position error between the axes is further increased than in the first embodiment. The synchronization accuracy can be further increased by keeping it small.

[Third Embodiment]
FIG. 3 is a block diagram of the motor control device 1 according to the third embodiment of the present invention.
In the motor control device 1 of FIG. 3, the first feedback control system 30 includes a first synchronization speed error generator 43, a first speed synchronization compensator 44, and a first synchronization compensation speed error generator as compared to the motor control apparatus 1 of FIG. 1. 45.
Based on the first control speed error of its own and the second control speed error generated by the second control speed error generator 77, the first synchronous speed error generator 43 determines the difference between these control speed errors (synchronous speed). A first synchronous speed error indicating an error) is generated. The first synchronization speed error may be, for example, a value obtained by subtracting another second control speed error from its own first control speed error. In this case, a synchronous speed error of the first feedback control system 30 with respect to the second feedback control system 70 is obtained.
The first speed synchronization compensator 44 generates a first speed error compensation amount from the first synchronization speed error. The first speed synchronization compensator 44 may be, for example, a proportional controller. Further, when compensating for a steady speed deviation, a proportional-integral controller may be used.
The first synchronization compensation speed error generator 45 includes a first control speed error that is a control speed error in the first feedback control system 30 and a first speed error compensation amount that is a synchronization speed error between the two feedback control systems. Based on the above, the first control speed error after the synchronization compensation process is generated. The first control speed error after the synchronization compensation process may be, for example, a total value obtained by adding the first control speed error and the first speed error compensation amount.
The first speed controller 38 generates a first control torque from the first control speed error after the synchronization compensation process. The first speed controller 38 generates a first control torque according to the control speed error in the first feedback control system 30, the first model speed command, and the synchronous speed error between the axes. When the control speed of the second feedback control system 70 is delayed as compared with the control speed of the first feedback control system 30, the first control torque increases.
Thereby, the first feedback control system 30 can compensate not only for the synchronization position error between the axes with the second feedback control system 70 but also for the synchronization speed error between the axes.
The other configuration and operation of the motor control device 1 of FIG. 3 are the same as those of FIG.

In the present embodiment, the first feedback control system 30 not only compensates the position error between the two axes with the second feedback control system 70 between the two feedback control systems, but also between the two axes. Is also compensated between the two feedback control systems. The first feedback control system 30 calculates a difference from the control speed error of the second feedback control system 70 by the first synchronous speed error generator 43, and compensates the difference by the first speed synchronous compensator 44. The error compensation amount is calculated, and the first control compensation speed error generator 45 generates the first control speed error after the synchronization compensation processing. As a result, even if the control response of each feedback control system is not high, it is possible to suppress the position error and the speed error between the axes and to increase the synchronization accuracy. It can be expected to synchronize with higher accuracy than in the first embodiment.
For this reason, for example, by causing the first feedback control system 30 and the second feedback control system 70 to follow the same rigid body model, it is difficult to generate a synchronization error. Even if a synchronization position error or a synchronization speed error due to a force difference or the like occurs, the synchronization error can be effectively suppressed.
As described above, in this embodiment, each model control system is configured using a rigid body model in a machine in which one movable part is driven by a plurality of (here, two) motors, and the actual model is made to follow the model. By causing the feedback control system to execute control, it is possible to improve the followability to the position command even when the feedback response of the control system that controls the individual motors cannot be enhanced.

The above embodiment is an example in which two sets of model control system and feedback control system are used in order to drive the movable part with two motors. Further, this is an example in which a synchronous speed error generator, a speed synchronous compensator, and a synchronous compensated speed error generator are applied to the first feedback control system.
In addition, the synchronous speed error generator, the speed synchronous compensator, and the synchronous compensated speed error generator may be applied to the second feedback control system.
In addition, the movable part may be driven by three or more motors. In this case, the model control system and the feedback control system may basically be provided in the same number of sets as the motor. When N (N is a natural number of 2 or more) motors are used, the synchronous speed error generator, the speed synchronous compensator, and the synchronous compensated speed error generator are added to (N−1) feedback control systems. What is necessary is just to provide. In the (N−1) feedback control systems, the (N−1) synchronization speed error generators may generate a position synchronization error with the control speed error of the remaining one feedback control system. .

[Fourth Embodiment]
FIG. 4 is a block diagram of a motor control device 1 according to the fourth embodiment of the present invention.
In the motor control device 1 of FIG. 4, the second feedback control system 70 includes a second synchronization speed error generator 83, a second speed synchronization compensator 84, and a second synchronization compensation speed error generation, as compared with that of FIG. 3. The difference is that the device 85 is provided.
The second synchronization speed error generator 83, the second speed synchronization compensator 84, and the second synchronization compensation speed error generator 85 are the first synchronization speed error generator 43, the first speed synchronization compensator 44, and the first synchronization. This corresponds to the compensation speed error generator 45.
Based on the second control speed error of its own and the first control speed error generated by the first control speed error generator 37, the second synchronous speed error generator 83 generates a difference between these control speed errors (synchronous speed). A second synchronization speed error indicating an error) is generated. The second synchronization speed error may be, for example, a value obtained by subtracting another first control speed error from its own second control speed error. In this case, a synchronization speed error of the second feedback control system 70 with respect to the first feedback control system 30 is obtained.
The second speed synchronization compensator 84 generates a second speed error compensation amount from the second synchronization speed error. In this embodiment, since compensation is applied between the first feedback control system 30 and the second feedback control system 70, the first speed synchronization compensator 44 and the second speed synchronization compensator 84 are proportionally controlled. Use a vessel.
The second synchronization compensation speed error generator 85 is a second control speed error that is a control speed error in the second feedback control system 70 and a second speed error compensation amount that is a synchronization speed error between the two feedback control systems. Based on the above, the second control speed error after the synchronization compensation process is generated. The second control speed error after the synchronization compensation process may be, for example, a total value obtained by adding the second control speed error and the second speed error compensation amount.
The second speed controller 78 generates a second control torque from the second control speed error after the synchronization compensation process. The second speed controller 78 generates a second control torque according to the control speed error in the second feedback control system 70, the second model speed command, and the inter-axis synchronous speed error. When the control speed of the first feedback control system 30 is delayed as compared with the control speed of the second feedback control system 70, the second control torque increases.
The other configuration and operation of the motor control device 1 shown in FIG. 4 are the same as those shown in FIG.

In this embodiment, the first feedback control system 30 and the second feedback control system 70 not only compensate for the position error between the two axes between the two feedback control systems, but also the speed between the two axes. The error is also compensated for between the two feedback control systems. As a result, even if the control response of each feedback control system is not high, the position error and the speed error between the axes can be suppressed to be small and the synchronization accuracy can be improved. A higher synchronization accuracy than that of the third embodiment can be expected.
For this reason, for example, by causing the first feedback control system 30 and the second feedback control system 70 to follow the same rigid body model, it is difficult to generate a synchronization error. Even if a synchronization position error or a synchronization speed error due to a force difference or the like occurs, the synchronization error can be more effectively suppressed than in the third embodiment.
As described above, in this embodiment, each model control system is configured using a rigid body model in a machine in which one movable part is driven by a plurality of (here, two) motors, and the actual model is made to follow the model. By causing the feedback control system to execute control, it is possible to improve the followability to the position command even when the feedback response of the control system that controls the individual motors cannot be enhanced. Further, since both the position error and the speed error between the axes are directly compensated for among the plurality (here, two) of feedback control systems, even if the control response of each feedback control system is not high. The position error and the speed error between the axes can be further reduced as compared with the third embodiment, and the synchronization accuracy can be further increased.

  The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications or changes can be made without departing from the scope of the invention.

For example, in the motor control device 1 of the above-described embodiment, two motors of the first motor 2 and the second motor 3 jointly drive one movable part.
In addition, for example, in the motor control device 1, three or more motors may jointly drive one movable part. In this case, the number of model control systems and feedback control systems may be the same as the number of motors.
Further, the number of model control systems may be smaller than the number of feedback control systems. In this case, a common model control command may be output from one model control system to a plurality of feedback control systems. N feedback control systems may be provided for N motors (N: a natural number of 2 or more), and model control systems may be provided for N motors or less.

In the above-described embodiment, the components of the model control system basically have a one-to-one correspondence with the components of the feedback control system that actually performs control following that. As a model corresponding to the mechanical system from the motor to the table 4, a rigid body model that does not cause vibration is used, which is based only on the movable part model.
In addition to this, for example, the constituent elements of the model control system may not correspond one-to-one with the constituent elements of the feedback control system that actually executes control following the control. The model control system only needs to be able to generate a model command that hardly causes vibrations in a feedback control system that operates based on the model command.

DESCRIPTION OF SYMBOLS 1 ... Motor control apparatus 2 ... 1st motor 3 ... 2nd motor 4 ... Table (movable part)
5 ... 1st ball screw 6 ... 2nd ball screw 10 ... 1st model control system 11 ... 1st model position error calculator 12 ... 1st model position controller 13 ... 1st model speed calculator 14 ... 1st model speed error calculation 15 ... first model speed controller 16 ... first model torque command low pass filter (model low pass filter)
17 ... 1st movable part model 30 ... 1st feedback control system 31 ... 1st control position error generator 32 ... 1st synchronous position error generator 33 ... 1st position synchronous compensator 34 ... 1st synchronous compensation position error generator 35 ... 1st position controller 36 ... 1st detection speed generator 37 ... 1st control speed error generator 38 ... 1st speed controller 39 ... 1st control torque generator 40 ... 1st torque command low pass filter (control low pass) filter)
41 ... 1st torque controller 42 ... 1st sensor 43 ... 1st synchronous speed error generator 44 ... 1st speed synchronous compensator 45 ... 1st synchronous compensation speed error generator 50 ... 2nd model control system 51 ... 2nd Model position error calculator 52 ... second model position controller 53 ... second model speed calculator 54 ... second model speed error calculator 55 ... second model speed controller 56 ... second model torque command low pass filter (model low pass) filter)
57 second movable part model 70 second feedback control system 71 second control position error generator 72 second synchronization position error generator 73 second position synchronization compensator 74 second synchronization compensation position error generator 75 ... second position controller 76 ... second detection speed generator 77 ... second control speed error generator 78 ... second speed controller 79 ... second control torque generator 80 ... second torque command low pass filter (control low pass) filter)
81 ... second torque controller 82 ... second sensor 83 ... second synchronization speed error generator 84 ... second speed synchronization compensator 85 ... second synchronization compensation speed error generator

Claims (5)

One of the N driven based on the common external position command for instructing the position of the movable part: by driving a more jointly movable portion (N 2 or greater natural number) respectively linked ball screw motor A motor control device for positioning the movable part ,
The movement of the movable part driven by the said motor, the movable portion represented by rigid-body model that describes the mechanical system from the said motor to said movable part driven jointly by the ball screw coupled to the motor A model control system including a model, wherein the model control system generates a model command including a model position command from the external position command; and
N feedback control systems provided in a one-to-one correspondence with the N motors and performing feedback control of the respective motors based on the model command;
Have
The external position command is a command for instructing the position of the movable part,
N model control systems are provided in a one-to-one correspondence with the N feedback control systems,
N model control systems generate the same model position command from the common external position command with the same feedback loop configuration,
Each said model control system further includes
A model position error calculator that calculates a model position error by subtracting a model position output from the movable part model from the external position command;
Each of the N feedback control systems further includes:
A control position error generator for generating a control position error indicating these position errors based on the model position command and a position detected by a sensor that detects the position of each of the motors; Each of the feedback control systems further includes
A synchronous position error generator for generating a difference between each of the control position errors and the control position error of the remaining one feedback control system;
Due to the difference between the control position error when controlling each motor and the control position error in the remaining one feedback control system, the (N−1) feedback control systems Compensating for the difference between the control position error and the control position error in the remaining one feedback control system;
Each said model control system further includes
A model position controller for calculating a model velocity from the model position error;
A model speed calculator for calculating a model detection speed as a model speed command which is one of the model commands from the model position output from the movable part model;
A model speed error calculator for calculating a model speed error by subtracting the model detection speed from the model speed;
A model speed controller that calculates a model torque as a model torque command that is one of the model commands from the model speed error;
A model low-pass filter for low-pass filtering the model torque, and based on the model torque after the low-pass filter processing by the movable part model corresponding to the movement of the movable part driven by the motor Calculating the model position;
Each of the N feedback control systems is
A position controller for generating a control speed from the control position error;
A detection speed generator that generates a detection speed from the position detected by the sensor that detects the position of each of the motors;
A control speed error generator that generates a control speed error by adding the model speed command to a speed error between the control speed and the detected speed based on the control speed, the detected speed, and the model speed command;
A speed controller for generating a control torque from the control speed error;
A control torque generator for generating a total control torque indicating the sum of these based on the control torque and the model torque command;
A control low-pass filter for low-pass filtering the total control torque;
A torque controller that controls each of the motors based on the total control torque after low-pass filter processing;
The position controllers in the N−1 feedback control systems generate the control speed from the compensated control position error, and the position controllers in the remaining one feedback control system perform the compensation. A motor control device that generates the control speed from the control position error that is not performed. One of the N driven based on the common external position command for instructing the position of the movable part: by driving a more jointly movable portion (N 2 or greater natural number) respectively linked ball screw motor A motor control device for positioning the movable part ,
The movement of the movable part driven by the said motor, the movable portion represented by rigid-body model that describes the mechanical system from the said motor to said movable part driven jointly by the ball screw coupled to the motor A model control system including a model, wherein the model control system generates a model command including a model position command from the external position command; and
N feedback control systems provided in a one-to-one correspondence with the N motors and performing feedback control of the respective motors based on the model command;
Have
The external position command is a command for instructing the position of the movable part,
N model control systems are provided in a one-to-one correspondence with the N feedback control systems,
N model control systems generate the same model position command from the common external position command with the same feedback loop configuration,
Each said model control system further includes
A model position error calculator that calculates a model position error by subtracting a model position output from the movable part model from the external position command;
Each of the N feedback control systems further includes:
A control position error generator for generating a control position error indicating these position errors based on the model position command and a position detected by a sensor that detects the position of each of the motors; Each of the feedback control systems further includes
A synchronous position error generator for generating a difference between each of the control position errors and the control position error of the remaining one feedback control system;
Due to the difference between the control position error when controlling each motor and the control position error in the remaining one feedback control system, the (N−1) feedback control systems Compensating for the difference between the control position error and the control position error in the remaining one feedback control system;
Each of the N feedback control systems further includes:
A position controller for generating a control speed from the control position error;
A detection speed generator that generates a detection speed from the position detected by the sensor that detects the position of each of the motors;
Based on the control speed, the detected speed, and the model speed command which is one of the model commands, a control speed error is generated by adding the model speed command to the speed error between the control speed and the detected speed. A control speed error generator,
The position controllers in the N−1 feedback control systems generate the control speed from the compensated control position error, and the position controllers in the remaining one feedback control system perform the compensation. Generating the control speed from the control position error that is not
Each of the (N-1) feedback control systems further includes:
A synchronous speed error generator for generating a difference between each of the control speed errors and the control speed error of the remaining one feedback control system;
The control speed error when controlling each of the motors is compensated by a difference from the control speed error in the remaining one feedback control system,
Each said model control system further includes
A model position controller for calculating a model velocity from the model position error;
A model speed calculator for calculating a model detection speed as a model speed command which is one of the model commands from the model position output from the movable part model;
A model speed error calculator for calculating a model speed error by subtracting the model detection speed from the model speed;
A model speed controller that calculates a model torque as a model torque command that is one of the model commands from the model speed error;
A model low-pass filter for low-pass filtering the model torque, and based on the model torque after the low-pass filter processing by the movable part model corresponding to the movement of the movable part driven by the motor Calculating the model position;
Each of the N feedback control systems further includes:
A speed controller for generating a control torque from the control speed error;
A control torque generator for generating a total control torque indicating the sum of these based on the control torque and the model torque command;
A control low-pass filter for low-pass filtering the total control torque;
A torque controller that controls each of the motors based on the total control torque after low-pass filter processing;
The speed controllers in the N−1 feedback control systems generate the control torque from the compensated control speed error, and the speed controllers in the remaining one feedback control system perform the compensation. A motor control device that generates the control torque from the control speed error that is not performed. The N model feedback control systems are simultaneously input with the same model position command from the model control system.
The motor control device according to claim 1 or 2. There are two feedback control systems,
Each of the feedback control systems obtains a difference between the control position error in itself and the control position error in the other feedback control system,
2. The motor according to claim 1, wherein the two feedback control systems compensate each other for the control position error for controlling the motor in each of them by a difference from the control position error in the other feedback control system. Control device. There are two feedback control systems,
Each feedback control system obtains a difference between the control speed error in itself and the control speed error in the other feedback control system,
3. The motor according to claim 2, wherein the two feedback control systems compensate each other for the control speed error for controlling the motor in each by a difference from the control speed error in the other feedback control system. Control device.

Images