JP2501529Y2 - Motor tracking controller - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a tracking control device for an electric motor.

B. Overview of the Invention The present invention is a tracking control device that causes a tracking-side motor to follow the speed of a reference-side motor. By detecting the phase difference from the pulse and adjusting the current command of the tracking side motor by the phase control calculation, the tracking delay of the tracking side motor is reduced.

C. Conventional technology The follow-up operation of the electric motor is carried out, for example, for constant speed control or zero differential rotation control of the electric motors which are respectively coupled to the front, rear, left and right wheels of the automobile (sample) in the dynamometer. Moreover, it is implemented in a parallel operation system of a large number of electric motors such as a production line of paper, film, steel plate and the like.

FIG. 2 shows a conventional tracking control device. The electric motor 1 is set as a reference electric motor, the speed is set by the setter 2, the speed control unit 3 performs speed control calculation, and the calculation result is used as a current command for current control by the current control unit 4 which becomes a minor control system. . The speed is detected by a pulse pickup 5 coupled to the electric motor 1 and a frequency-voltage converter 6 that converts the output pulse of the pulse pickup 5 into a voltage signal. The speed command for the electric motor 7 is used. The electric motor 7 has a speed control unit 8 and a current control unit 9 which is a minor system of the speed control unit 8 for speed control, and a pulse pickup 10 is used for speed detection for this purpose.
And a frequency-voltage converter 11 are provided.

With this configuration, the electric motor 1 on the reference side has the setting device 2
The speed control is performed so as to match the set speed, and the electric motor 7 on the follower side performs speed control so that the detected speed value of the electric motor 1 is set as the set speed.

The motors 1 and 7 are subjected to torque control and running resistance control depending on the test items.For this control, the speed control unit 3, 8 etc., which is the major control system of the motor, switches to the torque control system or running resistance control system. To be

D. Problem to be Solved by the Invention In the conventional tracking control device, the speed control unit 8 performs speed control calculation by using the speed detection value of the reference side electric motor 1 as a speed command to control the speed of the tracking side electric motor 7. . Therefore, the follow-up electric motor 2 causes a follow-up delay with respect to the reference-side electric motor 1 due to a response delay of the speed control unit 8 or the like, and this delay gives a rotation difference to the test piece or the driving equipment or causes a large torque shock. There was an inconvenience.

An object of the present invention is to provide a tracking control device in which the tracking delay of the tracking side electric motor with respect to the reference side electric motor is reduced.

E. Means and Actions for Solving the Problem In order to achieve the above-mentioned object, the present invention provides a first pulse pickup for detecting the speed of the reference side electric motor and an automatic control calculation result of the speed or torque of the reference side electric motor. A first current controller that controls the current of the reference side electric motor as a current command; and a load sharing setter that performs a coefficient calculation on the current command using a load sharing ratio between the reference side electric motor and the follower side electric motor as a coefficient. A second current control unit that controls the current of the tracking side electric motor by using the result of the coefficient calculation as a current command; a second pulse pickup that detects the speed of the tracking side electric motor; and a first pulse pickup of the first pulse pickup. The output pulse is used as an up-count input, and the output pulse of the second pulse pickup is used as a down-count input, and the deviation of the rotational phase of the both motors is counted. , A microcomputer for performing automatic phase control calculation for obtaining a calculation result in the direction of reducing the deviation to zero by a proportional integral calculation of the deviation of the count value, and a calculation result of the microcomputer Is converted into an analog signal and added to the output of the load sharing setting device to be a current command of the second current control unit, and a D / A converter is provided, and the speed, torque, running resistance, etc. of the reference side electric motor The current command obtained from the control calculation result is used as the current command for the following motors by calculating the load sharing ratio as a coefficient to control the currents of both motors, and the phase difference is detected from the difference in the speed detection pulses of both motors. And the phase difference control calculation is performed to adjust the current command of the follower electric motor, thereby obtaining the synchronous control of both electric motors.

F. Embodiment FIG. 1 is a device configuration diagram showing an embodiment of the present invention.
2 is different from FIG. 2 in that a synchronization control unit 12 and a load sharing setter 13 are provided in place of the speed control unit 8. The synchronization control unit 12 has an up / down counter 14 that receives the output pulse of the pulse pickup 5 as an up-count input and the output pulse of the pulse pickup 10 as a down-count input.
And a microcomputer 15 that performs automatic phase control calculation for obtaining a calculation result in a direction in which the deviation between the count values of the up-count input and the down-count input is zero by proportional-plus-integral (PI) calculation according to this count value, This calculation result is converted into an analog signal and used as a current adjustment signal for the electric motor D /
And an A converter 16. The load sharing setting device 13 is the motor 1
The current command signal for the electric motor 7 is obtained by the coefficient calculation according to the load sharing ratio of the electric motor 7.

In such a configuration, in the operation control of the electric motor 1 and the electric motor 7, basically, a common current command from the speed control unit 3 is given to both the current control units 4 and 9 through the load sharing setting unit 13, and the setting unit 13 is set. When the setting ratio is 1: 1, the speed control unit 3 performs speed control while current control is performed so that the electric motors 1 and 7 have the same driving force or absorbing force. Then, when the load sharing ratios of the electric motors 1 and 7 are different, the same speed control is performed with the respective sharing driving force or absorbing force.

In this speed control, when a differential rotation occurs between the electric motors 1 and 7, the output pulse of the pulse pickups 5 and 10 is detected as a phase difference between the electric motors 1 and 7 in the count value of the up / down counter 14 with a delay of one pulse period. It Based on this detected phase difference, the microcomputer 15 obtains a calculation output in the direction (synchronization) in which the phase difference becomes zero, and the calculation output adjusts the current command to the current controller 9. By this adjustment, the electric motor 7 is accelerated and decelerated, and the synchronous control is performed so that the phase difference with respect to the electric motor 1 becomes zero, that is, the count value of the up-down counter 14 becomes zero.

In this synchronous control, the differential rotation is detected by the motors 1 and 7
The output pulse from the pulse pickups 5 and 10 is directly taken out as a phase difference into the count value of the up / down counter 14, and the delay time is made extremely small as compared with the detection through the conventional converters 6 and 11. Then, the adjustment calculation by the microcomputer 15 is also performed at high speed to reduce the differential rotation zero, that is, the delay of the follow-up control.

For example, in the conventional device, the response speed ωc is 5 to 2 (rad /
s), but in this embodiment, the response speed ωc is one digit faster.
= 50 to 20 (rad / s), which is 1/10 of the conventional level even for disturbance occurrence
It is possible to suppress fluctuations in rotation speed.

Further, the speed control is basically performed by adjusting the current command through the load sharing setter 13, so that when the speed command is changed, synchronous control is performed in a state in which the current command is adjusted in advance. The synchronous control is performed where the system is close to a stable state, resulting in stable and synchronized follow-up control.

In the embodiment, the speed control unit 3 may be an arithmetic control unit such as torque control or running resistance control to obtain the same effect.

G. Effect of the Invention As described above, according to the present invention, the value calculated by the load sharing ratio from the current command of the reference motor is used as the current command of the following motor, and the phase difference is detected from the speed detection pulse of both motors. Since the synchronous control for adjusting the current command of the follower motor is performed by the phase control calculation, the follower delay of the follower motor can be reduced and stable follow-up control can be achieved.

[Brief description of drawings]

FIG. 1 is an apparatus configuration diagram showing an embodiment of the present invention, and FIG. 2 is a conventional apparatus configuration diagram. 1 ... Reference side electric motor, 3 ... Speed control unit, 4, 9 ... Current control unit, 5, 10 ... Pulse pickup, 7 ... Follow-up side electric motor, 12
… Synchronous control unit, 13… Load sharing setting device, 14… Up / down counter, 15… Microcomputer, 16… D / A converter.

Claims (1)

(57) [Scope of utility model registration request] 1. A follow-up control device for an electric motor that causes a reference-side electric motor to follow the reference-side electric motor, the first pulse pick-up detecting a speed of the reference-side electric motor, and an automatic speed or torque of the reference-side electric motor. A first current control unit that controls the current of the reference side electric motor by using the control calculation result as a current command, and a coefficient calculation is performed on the current command by using a load sharing ratio between the reference side electric motor and the follower side electric motor as a coefficient. A load sharing setting device, a second current control unit that controls the current of the tracking electric motor by using the result of the coefficient calculation as a current command, a second pulse pickup that detects the speed of the tracking electric motor, and The output pulse of the first pulse pickup is used as an up-count input and the output pulse of the second pulse pickup is used as a down-count input to rotate both electric motors. An up / down counter that detects a phase deviation as a deviation between the count values of the both pulses, and an automatic phase control calculation for obtaining a calculation result in a direction in which the deviation becomes zero by a proportional integral calculation of the deviation between the count values. A microcomputer, and a calculation result of the microcomputer, converted into an analog signal, added to an output of the load sharing setting device, and added to the second
And a D / A converter that outputs a current command of the current control unit of 1.