TW201711824A - Motor control apparatus - Google Patents

Abstract

A motor control apparatus is provided which can synchronously control three or more motors and also can synchronize the motors accurately even when a torque command is saturated. When a torque command for any of the motors is saturated, the motor control apparatus limits the rates of change of speed of the other motors to the acceleration of the motor having the smallest acceleration.

Description

Motor control unit

The invention relates to a motor control device.

In the large-sized placement machine and the large-sized work machine, the one movable portion is driven by two motors, and on the one hand, the yaw caused by the movable portion is suppressed, and the positional accuracy is improved. In the large-scale injection molding machine, the machine is miniaturized by driving one movable portion with two motors.

In the technique described in Japanese Laid-Open Patent Publication No. S61-237615, a ball screw is provided on both sides of the injection screw. The injection screw is driven by two motors. The two motors are controlled synchronously. The motor control device for driving the motor is limited to the torque command via the torque limiter according to the limit of the maximum current that the motor control device can output. However, when there is a difference between the torque constants of the two motors, the torque command of the shaft having a small torque constant is first limited and thus saturated. If the torque command is saturated, it is impossible to output a larger torque. For this reason, the torque of the shaft having a large moment constant becomes larger than the moment of the shaft. the result, The connection portions of the two ball screws are not perpendicular to the ball screw. For this reason, there is a possibility that excessive force is applied to the ball screw and the ball screw may be broken.

Japanese Laid-Open Patent Publication No. 2015-120302 discloses a technique for improving synchronism between motors when torque is limited. In the technique of this document, in order to protect the driven member, in order to reduce the torque limit value to a value lower than the value determined by the limitation that the motor control device can output the maximum current, in order to maintain the motor between well Synchronization, implementation of corrections. Specifically, regarding the position difference or the speed difference (synchronization error) between the two axes, the correction value obtained by the proportional-integral calculation is used to correct the torque limit value. Through this, the torque limit value of each axis is corrected to reduce the synchronization error. As a result, the synchronization between the two axes can be satisfactorily maintained.

The method described in the above-mentioned Japanese Laid-Open Patent Publication No. 2015-120302 is applied to a configuration of three or more axes. In the same literature, the torque limit value of only the slave axis is corrected. In other words, it does not take into account the correction of both the main axis and the subordinate axis. In this way, for example, when the torque limit value reaches the maximum output value of the motor control device, if the slave axis is rubbed, the torque limit value of the slave axis cannot be set larger, resulting in a relationship between the two axes. Position offset. Moreover, in the technique of the same document, the torque limit value is corrected based on the position difference or the speed difference. For this reason, it is difficult to instantaneously detect the influence of the torque difference between the two axes. For this reason, adjustment of the proportional integral calculation parameters becomes difficult. As a result, there is a possibility that it is difficult to sufficiently reduce the synchronization error.

The present invention has been made in view of the above problems. One object of the present invention is to provide the following motor control device. The motor control device can synchronously control three or more motors. Furthermore, the motor control device can accurately synchronize the motors even when the torque command is saturated.

The motor control device in the same state of the present invention limits the speed change rate of the other motor to the acceleration of the motor with the smallest acceleration when the torque command of any one of the motors is saturated.

According to this motor control device, even if there is a difference between the torque constant of each motor and the friction of the mechanical system, the acceleration accuracy of each motor can be accurately synchronized when the torque command is saturated. Further, even when three or more motors are synchronously controlled, the motor control device can be used.

For example, the motor control device includes a motor control unit that controls each of the motors so that a plurality of motors are synchronized with each other; the motor control unit includes a torque command saturation detector, and the torque command saturation detector is related to the torque of the motor. Detection is performed when the command reaches the given limit value and is saturated; the motor control unit is for each of the aforementioned motors When any one of the torque commands is saturated, the speed change rate of the other motor is limited to the acceleration of the plurality of motors, and the minimum acceleration.

110‧‧‧1st position controller

120‧‧‧1st speed change rate limiter

130‧‧‧Speed Controller

140‧‧‧ Torque limiter

150‧‧‧1st torque command saturation detector

160‧‧‧ Torque controller

170‧‧‧Average position calculator

210‧‧‧ position compensator

220‧‧‧2nd speed change rate limiter

230‧‧‧ speed controller

240‧‧‧ torque limiter

250‧‧‧2nd torque command saturation detector

260‧‧‧ Torque controller

270‧‧‧2nd position controller

310‧‧‧ Position compensator

320‧‧‧3rd speed change rate limiter

330‧‧‧Speed controller

340‧‧‧ torque limiter

350‧‧‧3rd Torque Command Saturation Detector

360‧‧‧ Torque Controller

410‧‧‧1st motor

420‧‧‧1st rotary position sensor

430‧‧‧2nd motor

440‧‧‧2nd rotational position sensor

450‧‧‧3rd motor

500‧‧‧Mechanical

1000‧‧‧Motor control unit

A1‧‧‧1st acceleration

V1‧‧‧1st speed

A2‧‧‧2nd acceleration

V2‧‧‧2nd speed

A3‧‧‧3rd acceleration

V3‧‧‧3rd speed

Fig. 1 is a control block diagram showing a configuration of a motor control device according to a first embodiment.

Fig. 2 is a control block diagram showing a configuration of a motor control device according to a second embodiment.

Fig. 3 is a control block diagram showing a configuration of a motor control device according to a third embodiment.

Fig. 4 is a control block diagram showing a configuration of a motor control device according to a fourth embodiment.

Fig. 5 is a control block diagram showing a configuration of a motor control device according to a fifth embodiment.

Fig. 6 is a control block diagram showing a configuration of a motor control device according to a sixth embodiment.

In the following detailed description, numerous specific details are set forth However, it should be understood that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown schematically to simplify the drawings.

<Embodiment 1>

1 is a control block diagram showing a configuration of a motor control device 1000 according to a first embodiment (Embodiment 1) of the present invention. In the motor control device 1000 according to the first embodiment, the first motor 410 and the second motor 430 of the drive machine 500 are driven in synchronization with each other. In Fig. 1, from the viewpoint of easy understanding, the control system of the first motor 410 and the control system for controlling the second motor 430 are controlled by a broken line frame. The motor control unit is constituted by these control systems. The operation of each member (controller or the like) provided in the motor control device 1000 will be described below.

The first rotational position sensor 420 detects the rotational position (first position) of the first motor 410. The second rotational position sensor 440 detects the rotational position (second position) of the second motor 430. As an example of these sensors, an encoder is exemplified. However, these sensors are not limited to encoders.

The motor control device 1000 obtains the speed (first speed) V1 of the first motor 410 by time-differentiating the first position, and obtains the first motor 410 by performing time division of the first position twice. Acceleration (1st acceleration) A1. These differential calculus, for example, can be implemented by a suitable differentiator. The differentiator for obtaining the first speed V1 can be disposed, for example, between the first rotational position sensor 420 and the speed controller 130 in FIG. A differentiator for obtaining the first acceleration A1, for example, by the first rotational position sensor positioned in FIG. Two differentiators on the downstream side of 420 are implemented. In other words, the other differential calculus described below can also be implemented by a suitable differentiator.

The motor control device 1000 receives a position command from the external device, for example, to the first motor 410. The position controller (first position controller) 110 calculates the first speed command for the first motor 410 based on the difference between the position command and the position (first position) of the first motor 410. The first speed command is configured (calculated) to compensate for the difference between the position command and the first position. The difference between the position command and the first position is obtained using a subtractor. The subtractor, for example, may also be disposed between the first rotational position sensor 420 and the position controller 110 in FIG. In other words, the other subtraction processing and addition processing described below may be performed by a suitable subtractor or an adder.

The first speed change rate limiter 120 limits the speed change rate of the first motor 410 by limiting the first speed command. In other words, the first speed change rate limiter 120 suppresses the rate of change of the first speed command when the torque command (second torque command) of the other motor (here, the second motor 430) is saturated. Thereby, the first speed change rate limiter 120 synchronizes the first motor 410 with the second motor 430. The details will be described later.

The speed controller 130 calculates the first torque command for the first motor 410 based on the difference between the first speed command and the first speed V1 in which the change rate is suppressed by the first speed change rate limiter 120. The first torque command is configured (calculated) to compensate for the difference between the first speed command and the first speed V1. The difference between the first speed command and the first speed V1 can be calculated, for example, by a subtracter disposed between the first speed change rate limiter 120 and the speed controller 130 in Fig. 1 .

The torque limiter 140 limits the first torque command so that when the first torque command from the speed controller 130 is equal to or greater than the maximum torque limit value, the first torque command from the torque limiter 140 does not exceed The aforementioned maximum torque limit value. That is, the torque limiter 140 performs torque limitation on the first torque command. The maximum torque limit value, for example, may be predetermined in accordance with the maximum output current of the motor control device 1000. The same applies to the torque limit values of the other motors described below.

When the first torque command from the speed controller 130 does not reach the maximum torque limit value, the torque limiter 140 can output the first torque command from the speed controller 130 as it is. The torque controller 160 can drive the first motor 410 by controlling the torque of the first motor 410 based on the first torque command.

The first torque command saturation detector 150 determines that the first torque command is saturated when the first torque command is equal to or greater than the maximum torque limit value. The first torque command saturation detector 150 notifies the speed change rate limiter (here, the second speed change rate limiter 220 to be described later) of the other motor when the first torque command is saturated. The reason why the first torque command is saturated is because the torque is limited by the torque limiter 140. The moment command is limited so as not to be a value higher than the maximum torque limit value. The same applies to the saturation of the torque command for other motors.

The torque controller 160 drives the first motor 410 such that the torque of the first motor 410 is controlled by the first torque command after the torque limitation.

The motor control device 1000 obtains the speed (second speed) V2 of the second motor 430 by time-differentiating the second position, and obtains the second motor 430 by performing time division of the second position twice. Acceleration (2nd acceleration) A2. The differentiator for determining the second speed V2 can be disposed, for example, between the first rotational position sensor 440 and the speed controller 230 in FIG. The differentiator for obtaining the second acceleration A2 can be implemented, for example, by two differentiators located on the downstream side of the second rotational position sensor 440 in FIG.

The position compensator 210 calculates a compensation value (compensation command) based on the difference between the first position and the second position. The compensation value is configured (calculated) to compensate for the difference between the position command (first position) of the second motor 430 and the second position. In other words, the position compensator 210 calculates a compensation command for compensating for the position of the second motor 430 based on the difference between the position of the first motor 410 and the position of the second motor 430. The difference between the first position and the second position can be calculated, for example, by a subtracter disposed between the second rotational position sensor 440 and the position compensator 210 in Fig. 1 .

The motor control device 1000 adds the compensation value output from the position compensator 210 to the first speed command value. In the manner, the second speed command to the second motor 430 is calculated. The addition of the compensation value (compensation command) and the first speed command, for example, can be performed by an adder (synthesizer) disposed between the position compensator 210 and the second speed change rate limiter 220 in FIG. And was implemented. In other words, the adder calculates the second speed command to the second motor 430 by integrating the first speed command and the compensation command.

The second speed change rate limiter 220 limits the speed change rate of the second motor 430 by limiting the second speed command. In other words, the second speed change rate limiter 220 suppresses the rate of change of the second speed command when the torque command (first torque command) of the other motor (here, the first motor 410) is saturated. Thereby, the second speed change rate limiter 220 synchronizes the second motor 430 with the first motor 410. The details will be described later.

The speed controller 230 calculates the second torque command to the second motor 430 based on the difference between the speed command in which the change rate is suppressed by the second speed change rate limiter 220 and the second speed V2. The second torque command is configured (calculated) to compensate for the difference between the second speed command and the second speed V2. The difference between the second speed command and the second speed V2 can be calculated, for example, by a subtracter disposed between the second speed change rate limiter 220 and the speed controller 230 in Fig. 1 .

The torque limiter 240 limits the second torque command to a second torque command from the torque limiter 240 when the second torque command from the speed controller 230 is equal to or greater than the maximum torque limit value. This maximum torque limit value will not be exceeded. That is, the torque limiter 240 performs torque limitation on the second torque command.

The second torque command saturation detector 250 determines that the second torque command is saturated when the second torque command is equal to or greater than the maximum torque limit value. The second torque command saturation detector 250 notifies the speed change rate limiter (here, the first speed change rate limiter 120) of the other motor that the second torque command is saturated. The torque controller 260 drives the second motor 430 by controlling the torque of the second motor 430 by the second torque command after the torque limitation.

When the second torque command from the speed controller 230 does not reach the maximum torque limit value, the torque limiter 240 can output the second torque command from the speed controller 230 as it is. The torque controller 260 can drive the second motor 430 so as to control the torque of the second motor 430 based on the second torque command.

The first speed change rate limiter 120 sets the rate of change of the first speed command to the second acceleration A2 when it is detected that the second torque command is saturated. As a result, the first speed change rate limiter 120 suppresses (limits) the rate of change of the first speed command, and avoids the case where the rate of change of the first speed command becomes equal to or higher than the second acceleration A2. When the second torque command is not saturated, the first speed change rate limiter 120 does not perform the process of suppressing (restricting) the rate of change of the first speed command, and the first speed command output from the position controller 110 is performed. Output as it is. In other words, the first speed change rate limiter 120 limits the first speed command (for example, limiting the rate of change of the first speed command). The speed change rate of the first motor 410 is limited.

The second speed change rate limiter 220 sets the rate of change of the second speed command to the first acceleration A1 when it is detected that the first torque command is saturated. As a result, the second speed change rate limiter 220 suppresses (limits) the rate of change of the second speed command, and avoids the case where the rate of change of the second speed command is equal to or higher than the first acceleration A1. When the first torque command is not saturated, the second speed change rate limiter 220 does not perform the process of suppressing (restricting) the rate of change of the second speed command, and outputs the second speed command as it is. In other words, the second speed change rate limiter 220 limits the speed change rate of the second motor 430 by limiting the second speed command (for example, limiting the rate of change of the second speed command).

When the torque command of any one of the motors is saturated by the above-described operations of the first speed change rate limiter 120 and the second speed change rate limiter 220, the rate of change of the speed command of the other motor is limited to the saturation of the torque command. The acceleration of the motor. Therefore, when the torque command is saturated, the acceleration of each motor can be synchronized with each other even if the friction of each motor shaft and/or the torque constant of each motor varies. The acceleration of the motor is obtained by differentiating the rotational position of the motor twice. Therefore, in the present embodiment, the positional shift between the motors can be suppressed in the dimension of the acceleration.

Further, when the first speed change rate limiter 120 saturates the torque command of the second motor 430, the speed change rate of the first motor 410 can be limited to the acceleration of each motor and the minimum acceleration. more Further, when the torque command of the first motor 410 is saturated, the second speed change rate limiter 220 can limit the speed change rate of the second motor 430 to the minimum acceleration among the accelerations of the motors.

As described above, the motor control device 1000 includes a motor control unit that controls each of the motors so that the plurality of motors are synchronized with each other. The motor control unit includes a torque command saturation detector that detects saturation due to a limit value given to the torque command of the motor. Furthermore, the motor control unit can limit the speed change rate of the other motors to the acceleration of the plurality of motors, and the minimum acceleration, if the torque command of any of the motors is saturated.

<Embodiment 2>

FIG. 2 is a control block diagram showing a configuration of a motor control device 1000 according to a second embodiment (Embodiment 2) of the present invention. In the motor control device 1000 according to the second embodiment, the first motor 410, the second motor 430, and the third motor 450 of the drive machine 500 are driven in synchronization with each other. The third rotational position sensor 460 detects the rotational position (third position) of the third motor 450. The motor control device 1000 according to the second embodiment has substantially the same configuration as that of the first embodiment except that it has a difference in control of three motors. Hereinafter, differences between the first embodiment and the second embodiment will be mainly described.

The first speed change rate limiter 120 is a torque finger to another motor (here, the second motor 430 or the third motor 450) When the command (that is, the second torque command or the third torque command) is saturated, the rate of change of the first speed command is suppressed. As a result, the first speed change rate limiter 120 synchronizes the first motor 410 with the other motors. The first torque command saturation detector 150 is a speed change rate limiter for the other motor when the first torque command is equal to or greater than the maximum torque limit value, and the second speed change rate limiter (the second speed change rate limiter) The device 220 and a third speed change rate limiter 320), which will be described later, notify. The other configuration of the control system for controlling the first motor 410 is the same as that of the first embodiment.

The second speed change rate limiter 220 is a torque command (that is, a first torque command or a third torque command) for another motor (here, the first motor 410 or the third motor 450). When saturated, the rate of change of the second speed command is suppressed. As a result, the second speed change rate limiter 220 synchronizes the second motor 430 with the other motors. The second torque command saturation detector 250 is a speed change rate limiter for the other motor when the second torque command is equal to or greater than the maximum torque limit value, and the first speed change rate limiter (the first speed change rate limit) The device 120 and a third speed change rate limiter 320), which will be described later, notify. The other configuration of the control system that controls the second motor 430 is the same as that of the first embodiment.

The position compensator 310 calculates the compensation value based on the difference between the first position and the third position. The compensation value The system is configured (calculated) to compensate for the difference between the position command (first position) of the third motor 450 and the third position. The difference between the first position and the third position can be calculated, for example, by a subtractor disposed between the third rotational position sensor 460 and the position compensator 310 in Fig. 1 .

The motor control device 1000 calculates the third speed command to the third motor 450 via the addition of the compensation value output from the position compensator 310 and the first speed command value. The addition of the compensation value (compensation command) and the first speed command, for example, can be performed by an adder (synthesizer) disposed between the position compensator 310 and the third speed change rate limiter 320 in FIG. And was implemented. In other words, the adder calculates the third speed command to the third motor 450 by integrating the first speed command and the compensation command.

The third speed change rate limiter 320 limits the speed change rate of the third motor 450 by limiting the third speed command. In other words, the third speed change rate limiter 320 is a torque command for the other motor (here, the first motor 410 or the second motor 430) (that is, the first torque command or the second torque). When the command is saturated, the rate of change of the third speed command is suppressed. As a result, the third speed change rate limiter 320 synchronizes the third motor 450 with the other motors.

The speed controller 330 calculates the third torque command for the third motor 450 based on the difference between the speed command in which the change rate is suppressed by the third speed change rate limiter 320 and the third speed V3. The third torque command is configured (calculated) to compensate for the difference between the third speed command and the third speed V3. The difference between the third speed command and the third speed V3 can be calculated, for example, by a subtracter disposed between the third speed change rate limiter 320 and the speed controller 330 in Fig. 1 .

The torque limiter 340 limits the third torque command to When the third torque command from the speed controller 330 is equal to or greater than the maximum torque limit value, the third torque command from the torque limiter 340 does not exceed the maximum torque limit value. That is, the torque limiter 340 performs torque limitation on the third torque command.

The third torque command saturation detector 350 determines that the third torque command is saturated when the third torque command is equal to or greater than the maximum torque limit value. When the third torque command is saturated, the third torque command saturation detector 350 performs a speed change rate limiter (the first speed change rate limiter 120 and the second speed change rate limiter 220) of the other motors. Notice. The torque controller 360 drives the third motor 450 by controlling the torque of the third motor 450 based on the third torque command after the torque limitation.

When the third torque command from the speed controller 330 does not reach the maximum torque limit value, the torque limiter 340 can output the third torque command from the speed controller 330 as it is. The torque controller 360 can drive the third motor 450 by controlling the torque of the third motor 450 based on the third torque command.

The other members (differentiators, etc.) of the control system of the third motor 450 perform the same functions as the members corresponding to the control system of the second motor 430.

The speed change rate limiter (the first speed change rate limiter 120, the second speed change rate limiter 220, and the third speed change rate limiter 320) of each control system is saturated with the torque command of any other motor. When, the rate of change of the speed command of the control system itself is limited. Among the accelerations of other motors, the minimum acceleration. When the torque command to the other motor is not saturated, the process of limiting the rate of change of the speed command is not performed.

For example, when the second torque command or the third torque command is saturated, the first speed change rate limiter 120 limits the rate of change of the first speed command to any of the second acceleration A2 and the third acceleration A3. For the smaller ones. Accordingly, the rate of change of the first speed command can be controlled so as not to exceed the minimum motor acceleration.

Through the above-described actions of the respective speed change rate limiters, when the torque command of a certain control system is saturated, the rate of change of the speed command of the control system is limited to the minimum acceleration of the other control systems. Therefore, when the torque command for any of the motors is saturated, the accelerations of the motors are controlled to be synchronized with each other. As a result, when the torque command for any of the motors is saturated, the accelerations of the motors can be synchronized with each other even if the friction of each of the motor shafts and/or the torque constant of each of the motors varies. As a result, the positional shift between the motors can be suppressed.

<Embodiment 3>

3 is a control block diagram showing a configuration of a motor control device 1000 according to a third embodiment (Embodiment 3) of the present invention. The motor control device 1000 according to the third embodiment further includes an average position calculator 170 in addition to the configuration described in the first embodiment, but does not include the position compensator 210. The other configuration is substantially the same as that of the first embodiment. Therefore, in the following, mainly, the first embodiment and the third embodiment The differences are explained.

The average position calculator 170 calculates an average (average position) between the first position and the second position. The position controller 110 calculates the first speed command based on the difference between the average position and the position command. The difference between the average position and the position command can be calculated, for example, by a subtractor between the position controller 110 and the average position calculator 170 in FIG. The first speed command is configured (calculated) to compensate for the difference between the position command and the average position. That is, the first speed command is controlled such that the average position is close to the position command. The other configuration of the control system of the first motor 410 is the same as that of the first embodiment.

The second speed change rate limiter 220 is different from the first embodiment in that the first speed command is used as the speed command for the second motor 430 (that is, the second speed command). In other words, the position controller 110 according to the third embodiment calculates the first speed command for the first motor 410 and the second motor 430 based on the difference between the position command and the average position of the first motor 410. 2 speed command. The second speed change rate limiter 220 limits the speed change rate of the second motor 430 by limiting the second speed command. The control of the rotational position of the second motor 430 is performed by compensating for the difference between the average position and the position command. The other configuration of the control system of the second motor 430 is the same as that of the first embodiment.

Also in the third embodiment, as in the first embodiment, when the torque command of any one of the motors is saturated, the rate of change of the speed command of the other motor is limited to the acceleration of the motor in which the torque command is saturated. through Thereby, the accelerations of the motors can be synchronized with each other.

<Embodiment 4>

FIG. 4 is a control block diagram showing a configuration of a motor control device 1000 according to a fourth embodiment (Embodiment 4) of the present invention. The motor control device 1000 according to the fourth embodiment includes a position controller (second position controller) 270 instead of the position compensator 210 described in the first embodiment. The other configuration is substantially the same as that of the first embodiment. Therefore, the differences between the first embodiment and the fourth embodiment will be mainly described below.

In the fourth embodiment, the position command of the first motor 410 is also used as a position command for the second motor 430. That is, each motor is controlled based on a position command (common position command) common between the motors. Specifically, the position controller 110 calculates the first speed command for the first motor 410 based on the difference between the common position command common to each motor and the position of the first motor. The position controller 270 calculates a second speed command based on the difference between the common position command and the second position. The second speed command is configured (calculated) to compensate for the difference between the common position command and the second position. The difference between the common position command and the second position, for example, can be subtracted by the upstream side of the position controller 270 (between the second rotational position sensor 440 and the position controller 270) arranged in FIG. The operator is calculated. The second speed change rate limiter 220 receives the second speed command calculated by the position controller 270 as it is. Other configurations are the same as in the first embodiment kind.

Also in the fourth embodiment, as in the first embodiment, when the torque command of any one of the motors is saturated, the rate of change of the speed command of the other motor is limited to the acceleration of the motor in which the torque command is saturated. Thereby, the accelerations of the motors can be synchronized with each other.

<Embodiment 5>

FIG. 5 is a control block diagram showing a configuration of a motor control device 1000 according to a fifth embodiment (Embodiment 5) of the present invention. The motor control device 1000 according to the fifth embodiment does not include the position controller 110 and the position compensator 210 in the configuration described in the first embodiment. Further, the motor control device 1000 receives a speed command for the first motor 410 instead of the position command to the first motor 410, for example, from an external device. The other configuration is basically the same as that of the first embodiment. Therefore, the differences between the first embodiment and the fifth embodiment will be mainly described below.

The first speed change rate limiter 120 uses the speed command received by the motor control device 1000 (the first speed command for the first motor) instead of the first speed command in the first embodiment. The second speed change rate limiter 220 uses the first speed V1 as the second speed command for the second motor instead of the second speed command in the first embodiment. Thereby, the speeds of the motors are controlled to be synchronized with each other. The other configuration is the same as that of the first embodiment.

Also in the fifth embodiment, as in the first embodiment, if the torque command of any one of the motors is saturated, the speed command of the other motor is also used. The rate of change is limited to the acceleration of the motor where the torque command is saturated. Thereby, the accelerations of the motors can be synchronized with each other.

<Embodiment 6>

Fig. 6 is a control block diagram showing a configuration of a motor control device 1000 according to a sixth embodiment (Embodiment 6) of the present invention. In the motor control device 1000 according to the sixth embodiment, as in the fifth embodiment, the position controller 110 and the position compensator 210 are not provided in the configuration described in the first embodiment. However, the second speed change rate limiter 220 of the sixth embodiment differs from the fifth embodiment in that the speed command for the first motor 410 is used as the second speed command instead of the first speed V1. That is, each motor is controlled based on a speed command common to each motor. The other configuration is the same as that of the fifth embodiment. The sixth embodiment can also exhibit the same effects as those of the fifth embodiment.

<Embodiment 7>

In the above-described first to sixth embodiments, when the torque command for any one of the motors is saturated, the speed change rate limiter of the other motor can limit the speed change rate of the corresponding motor to the acceleration of each motor. The minimum acceleration. In order to more effectively exert the effect of the method, each speed change rate limiter can limit the speed change rate of each motor to the acceleration of the motor in which all the torque commands are saturated, and the minimum acceleration. In other words, if the motor control unit saturates the torque command of any of the motors, the speed change rate of the other motors can be limited to the torque command. Among the accelerations of the saturated motors, the minimum acceleration.

For example, in the configuration described in the second embodiment, it is assumed that the second torque command and the third torque command are saturated. At this time, the first speed change rate limiter 120 limits the rate of change of the first speed command to the smaller one of the second acceleration A2 and the third acceleration A3. Accordingly, the rate of change of the first speed command can be controlled so as not to exceed the minimum acceleration of the acceleration of the motor in which the torque command is saturated. In the case where there is only one motor in which the torque command is saturated, the speed change rate of the other motor can be controlled so as not to exceed the acceleration of the motor. The same is true for only two motors.

<Modifications of the Present Invention>

The present invention is not limited to the above-described embodiments, and includes various modifications. For example, the above-described embodiments are described in detail in order to facilitate understanding of the present invention. The above-described embodiments are not necessarily limited to those having all of the members (configurations) described above. Further, it is possible to replace a member of a certain embodiment with a member of another embodiment. Further, in some embodiments, members of other embodiments may be added. Moreover, components of a part of each embodiment can be added. delete. Replace other components.

Each of the above-described members (each controller, limiter, compensator, detector, adder, subtractor, and differentiator) may be configured by using a hardware such as a circuit device that realizes the function, or may be utilized. Use the CPU with the software installed in this function (Central Processing A calculation device such as Unit) is implemented in a manner that is implemented.

The position controller and the position compensator described in the above embodiments 1 to 7 can be configured by, for example, a proportional controller. Moreover, the speed controller and the position compensator can be constructed, for example, by a proportional integral controller. If the difference can be appropriately compensated, as these controllers and/or compensators, other suitable controllers can also be used.

Also in the third to sixth embodiments, in the same manner as in the second embodiment, it is possible to synchronously control three or more motors and synchronize the accelerations of the motors when the torque command of any one is saturated. Specifically, for example, (a) each torque command saturation detector notifies the speed change rate limiter of the other control system that the torque command is saturated; (b) each speed change rate limiter is other If the torque command of the motor is saturated, the rate of change of the speed command is limited to the minimum motor acceleration.

In the above embodiments 1 to 7, the maximum torque limit value of the torque limiter can be substituted for the maximum output current of the motor control device 1000, and is based on the maximum torque limit value based on the limitation of the mechanical system. For example, the maximum torque limit value of the torque limiter can be determined to be less than the maximum torque limit value of the mechanical system limit. Alternatively, for example, the maximum torque limit value may be externally supplied to the motor control device 1000 through an appropriate interface. The maximum torque limit value can also be calculated by other appropriate means. Also in these cases, the accelerations of the motors can be synchronized in the same manner as in the first to seventh embodiments.

The speed controller 130 can be changed according to the first speed The rate limiter 120 suppresses the difference between the speed command of the first speed command and the first speed V1, and calculates the first torque command for the first motor 410. The speed controller 230 calculates the second torque command for the second motor 430 based on the difference between the speed command of the second speed command and the second speed V2 by the second speed change rate limiter 220. .

The torque limiter 140 is limited such that when the first torque command is equal to or greater than the maximum torque limit value, the first torque command does not exceed the maximum torque limit value. The torque limiter 240 is limited such that when the second torque command is equal to or greater than the maximum torque limit value, the second torque command does not exceed the maximum torque limit value.

The embodiment of the present invention may be the following first to seventh motor control devices.

The first motor control device includes a motor control unit that controls each of the motors, so that a plurality of motors are synchronized with each other; and the motor control unit includes a torque command saturation detector, and the torque command saturation detector is related to the motor When the torque command is saturated by the given limit value, the motor control unit detects that the torque command of any of the motors is saturated, and limits the speed change rate of the other motor to each of the foregoing. The acceleration of the motor is the smallest, and the acceleration of each of the aforementioned motors is synchronized.

In the first motor control device, the motor control unit controls the first motor and the second motor as the plurality of motors, and the motor control unit includes a position controller. Calculating a first speed command for the first motor based on a difference between a position command of the first motor and a position of the first motor; and the position compensator is based on the position of the first motor and the first a difference compensation command between the positions of the motors to calculate a compensation command for compensating the position of the second motor; and the first speed change rate limiter limits the speed change rate of the first motor by limiting the first speed command; By calculating the first speed command and the compensation command, calculating a second speed command for the second motor; and the second speed change rate limiter restricting the second by limiting the second speed command The speed change rate of the motor, wherein the first speed change rate limiter limits the speed change rate of the first motor to the smallest of the accelerations of the motors; The speed change rate limiter limits the speed change rate of the second motor to the acceleration of each of the motors when the torque command of the first motor is saturated. Small.

In the first motor control device, the motor control unit controls the first motor and the second motor as the plurality of motors, and the motor control unit includes an average position calculator that calculates The average position of the position of the first motor and the position of the second motor is averaged; and the position controller calculates the first motor for the first motor based on the difference between the position command of the first motor and the average position a speed command and a second speed command to the second motor; the first speed change rate limiter limits the speed change rate of the first motor by limiting the first speed command; and the second speed change rate limit The speed change rate of the second motor is limited by limiting the second speed command, and the first speed change rate limiter changes the speed of the first motor when the torque command of the second motor is saturated. The rate is limited to the smallest of the accelerations of the respective motors; and the second speed change rate limiter limits the speed change rate of the second motor to the acceleration of each of the motors when the torque command of the first motor is saturated. The smallest.

In the first motor control device, the motor control unit controls the first motor and the second motor as the plurality of motors, and the motor control unit includes a first position controller. Calculating a first speed command for the first motor based on a difference between a common position command common to the first motor and the second motor and a position of the first motor; and a second position controller Calculating a second speed command for the second motor based on a difference between the common position command and a position of the second motor; and the first speed change rate limiter limits the first by limiting the first speed command a speed change rate of the motor; and a second speed change rate limiter that limits a speed change rate of the second motor by limiting the second speed command; wherein the first speed change rate limiter is for the second motor When the torque command is saturated, the speed change rate of the first motor is limited to the smallest of the accelerations of the motors; and the second speed change rate limiter is for the first motor. When the torque command is saturated, the speed change rate of the second motor is limited to the smallest of the accelerations of the respective motors.

The fifth motor control device is the first motor control device The motor control unit controls the first motor and the second motor as the plurality of motors, and the motor control unit includes a first speed change rate limiter that limits the first speed to the first motor. a command to limit a speed change rate of the first motor; and a second speed change rate limiter to limit a speed change rate of the second motor by limiting a second speed command to the second motor; the first speed change The rate limiter limits the speed change rate of the first motor to the smallest of the accelerations of the motors, and the second speed change rate limiter is the first one. When the torque command of the motor is saturated, the speed change rate of the second motor is limited to the smallest of the accelerations of the respective motors.

In the fifth motor control device, the first motor speed control device and the second speed command are configured as speed commands common to the first motor and the second motor.

In the seventh motor control device, the motor control unit is configured to limit the speed change rate of the other motor to the torque command by the torque command of any of the motors. The smallest of the accelerations of the respective motors saturated is synchronized with the acceleration of each of the aforementioned motors.

The above detailed description has been presented for the purposes of illustration and description. Many modifications and variations are possible in light of the above teachings. It is not intended to be exhaustive or to limit the scope of the invention disclosed herein. Although the subject matter of the invention has been described in terms of specific structural features and/or methodological acts, it should be understood that the appended application The subject matter of the invention as defined by the scope of the invention is not necessarily limited to the specific features or acts described. Rather, the specific features and acts described above are disclosed as an embodiment of the scope of the application.

110‧‧‧1st position controller

120‧‧‧1st speed change rate limiter

130‧‧‧Speed Controller

140‧‧‧ Torque limiter

150‧‧‧1st torque command saturation detector

160‧‧‧ Torque controller

210‧‧‧ position compensator

220‧‧‧2nd speed change rate limiter

230‧‧‧ speed controller

240‧‧‧ torque limiter

250‧‧‧2nd torque command saturation detector

260‧‧‧ Torque controller

410‧‧‧1st motor

420‧‧‧1st rotary position sensor

430‧‧‧2nd motor

440‧‧‧2nd rotational position sensor

500‧‧‧Mechanical

1000‧‧‧Motor control unit

A1‧‧‧1st acceleration

V1‧‧‧1st speed

A2‧‧‧2nd acceleration

V2‧‧‧2nd speed

Claims (7)

A motor control device includes a motor control unit that controls each of the motors, so that a plurality of motors are synchronized with each other; and the motor control unit includes a torque command saturation detector, and the torque command saturation detector is related to the motor The torque command is detected when the torque command reaches the set limit value and is saturated. The motor control unit limits the speed change rate of the other motor to the plurality of motors when the torque command of each of the motors is saturated. The smallest acceleration in acceleration. The motor control device according to claim 1, wherein the motor control unit controls the first motor and the second motor as the plurality of motors; and the motor control unit includes a position controller based on the first motor Calculating a first speed command for the first motor by a difference between the position command and the position of the first motor; and the position compensator is based on a position between the position of the first motor and the position of the second motor Calculating a compensation command for compensating the position of the second motor; the first speed change rate limiter limits the speed change rate of the first motor by limiting the first speed command; and the first controller Speed command and the aforementioned compensation command Calculating a second speed command for the second motor; and the second speed change rate limiter limits the speed change rate of the second motor by limiting the second speed command; the first speed change rate limit When the torque command of the second motor is saturated, the speed change rate of the first motor is limited to the acceleration of each of the motors, and the minimum acceleration; and the second speed change rate limiter is When the torque command of the motor is saturated, the speed change rate of the second motor is limited to the acceleration of each of the motors and the minimum acceleration. The motor control device according to claim 1, wherein the motor control unit controls the first motor and the second motor as the plurality of motors; and the motor control unit includes an average position calculator that calculates the first motor The position controller and the average position of the position of the second motor; the position controller calculates a first speed command for the first motor and the foregoing based on a difference between the position command of the first motor and the average position a second speed command of the second motor; the first speed change rate limiter limits the speed change rate of the first motor by limiting the first speed command; and the second speed change rate limiter limits the first speed a speed command for limiting the speed change rate of the second motor; wherein the first speed change rate limiter limits the speed change rate of the first motor to the torque command of the second motor Among the accelerations of the motors, the minimum acceleration; the second speed change rate limiter limits the speed change rate of the second motor to the acceleration of each of the motors when the torque command of the first motor is saturated. , the minimum acceleration. The motor control device according to claim 1, wherein the motor control unit controls the first motor and the second motor as the plurality of motors; and the motor control unit includes a first position controller according to the first a difference between a common position command between the motor and the second motor and a position of the first motor to calculate a first speed command for the first motor; and a second position controller based on the common position a second speed command for the second motor is calculated by a difference between the command and the position of the second motor; and the first speed change rate limiter limits the speed change of the first motor by limiting the first speed command And a second speed change rate limiter that limits the speed change rate of the second motor by limiting the second speed command; and the first speed change rate limiter saturates the torque command of the second motor a speed change rate of the first motor is limited to an acceleration of each of the motors, and a minimum acceleration; and the second speed change rate limiter is for the first motor Saturated, then the torque command, the rate of change of the second motor, each of said motor to limit the acceleration, the minimum acceleration. The motor control device according to claim 1, wherein the motor control unit controls the first motor and the second motor as the plurality of motors; and the motor control unit includes a first speed change rate limiter via a limit Limiting the speed change rate of the first motor to the first speed command of the first motor; and limiting the speed change rate of the first motor by the second speed change rate limiter by limiting the second speed command to the second motor The first speed change rate limiter is configured to limit the speed change rate of the first motor to the acceleration of each of the motors, and the minimum acceleration when the torque command of the second motor is saturated; The speed change rate limiter limits the speed change rate of the second motor to the minimum acceleration of the acceleration of each of the motors when the torque command of the first motor is saturated. The motor control device according to claim 5, wherein the first speed command and the second speed command are speed commands common to the first motor and the second motor. The motor control device according to claim 1, wherein the motor control unit saturates the torque command of any one of the motors, and limits the speed change rate of the other motor to each of the torque command saturation. The minimum acceleration of the motor's acceleration.