JP2000347743A - Position controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device capable of performing highly accurate positioning in a short time by suppressing the vibrations of a position loop and increasing a position control gain. SOLUTION: This load position controller which performs speed control on the basis of a motor speed signal obtained by performing a differential operation of a rotational position signal of a motor and also performs positional control on the basis of a load position signal from a position detector attached to a load driven by the motor, is provided with a differential operating means 801 which performs a differential operation of a load position signal and outputs a load speed signal, a subtracting means 808 which operates the difference between the load speed signal and a speed command signal, a phase adjusting means 803 which performs phase adjustment by inputting a difference signal outputted by the means 808 to a lowpass filter, a proportion gaining means 802 which inputs an output signal of the means 803, and an adding means which adds an output signal of the means 802 to the speed command signal and outputs a new speed command signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position control device for performing position control based on a load position signal from a position detector attached to a load driven by a motor.

[0002]

2. Description of the Related Art In general, in high-precision positioning control, a position signal of an encoder or the like attached to a motor is differentiated into a speed feedback signal to perform speed control and to be attached to a load driven by the motor. Full-closed position control is performed based on a load position signal from a position detector such as a linear scale. A block diagram of such a full-closed control system is as shown in FIG. 6, 1 is the position control gain in the position control unit is K _p. Reference numeral 2 denotes a speed control unit, 3 denotes a motor, and 4 denotes a load (mechanical movable unit). From the position command y _r by subtracting the load position signal y _L obtain the position deviation e _p, the position deviation e _p
By multiplying the position control gain K _p from the speed command v _r is obtained. This speed command v speed from _r feedback signal v _f
The seek velocity error e _v is subtracted, the speed deviation e _v calculated torque command (current command) T _r in the speed control section 2 on the basis of the motor 3 based on the torque command T _r, the load 4 (mechanically movable Part) is driven. Recently, in the industrial machines, the demand for high accuracy and high speed is increased, because its, it is essential to increase the position control gain K _p in the full-closed control system. However, with respect to the resonance frequency is low control target, increasing the position control gain K _p, because the control system oscillates at a frequency of anti-resonance frequency near the upper limit at the upper limit of the position control gain K _p is a semi-closed system 1/2 of
Only about 2/3 can be obtained. Therefore, to suppress the vibration, to raise higher the position control gain K _p, combining the position loop stabilization compensating section as shown in FIG. 5 to the normal full-closed control system shown in FIG. 6, ie, the speed command basic signal v
_rb to the speed command correction signal v _rh to add a new speed command v _r
It has been proposed that In FIG. 5, reference numeral 801 denotes a differentiation processing unit, 807 denotes an integration processing unit, and 802 denotes a compensation gain. Speed command v _r and the load position signal y _L the differential processing unit 8
The difference from the load speed signal v _L obtained by the differential operation at 01 is output to the integration processing unit 807. The output signal of the integration processing unit 807 is _multiplied by an appropriate compensation gain _Kf to obtain a speed command correction signal v _rh .

[0003]

In the above prior art,
Since the integrated signal of the load speed signal is used, there is a problem that when a large frictional force exists in the load or an initial value of the integral exists, a steady-state error remains. SUMMARY OF THE INVENTION An object of the present invention is to provide a device that solves the above-mentioned problems of the prior art, suppresses the vibration of the position loop, and increases the position control gain to perform high-precision positioning in a short time. .

[0004]

According to a first aspect of the present invention, there is provided a position detector attached to a load driven by the motor, while performing speed control based on a motor speed signal obtained by differentiating a rotational position signal of the motor. A load position control device that performs position control based on a load position signal from a load position signal, calculates a differential between the load position signal and outputs a load speed signal, and calculates a difference between the load speed signal and a speed command signal. Subtraction means, phase adjustment means for performing phase adjustment by inputting a difference signal output from the subtraction means to a low-pass filter, proportional gain means for inputting an output signal of the phase adjustment means, and output of the proportional gain means A position control device comprising: an addition unit that adds a signal and the speed command signal to output a new speed command signal. The invention according to claim 2 is the position control device according to claim 1, wherein the phase adjustment unit performs phase adjustment by inputting a difference signal output from the subtraction unit to a band-pass filter. According to a third aspect of the present invention, the speed control is performed based on a motor speed signal obtained by differentiating the rotational position signal of the motor, and the position control is performed based on a load position signal from a position detector attached to a load driven by the motor. A load position control device that performs an integral operation on a speed command signal; a subtraction unit that computes a difference between the load position signal and an integral signal output by the integral operation unit; Phase adjustment means for adjusting the phase by inputting the difference signal to the band-pass filter, proportional gain means for inputting the output signal of the phase adjustment means, and adding the output signal of the proportional gain means and the speed command signal. And a adding means for outputting a new speed command signal.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration block diagram of a full-closed control system in which a position loop stabilization compensator is combined. FIG. 1 shows a conventional full-closed control system in which a position loop stabilization compensator 8 is added. Position command y _r and positional deviation e _p between the load position signal y _L from the position detector 6 of the linear scale or the like is calculated. The position controller 1 multiplies the position deviation e _p by a position control gain K _p to obtain a speed command basic amount v _rb , and the speed command basic amount v _rb and the position loop stabilization compensator 8
A signal obtained by synthesizing the speed command correction amount v _rh (described later) calculated in the above is defined as a speed command v _r . Speed control unit 2, based on the speed command v _r and the speed deviation e _v of the speed feedback signal v _f to a position signal y _m of the motor from the encoder 5 attached to the motor 3 and differential operation by the differential processing section 7 To calculate the torque command _Tr and output it to the motor 3. The configuration of the position loop stabilization compensator 8 will be described with reference to FIGS. 2, 3, and 4. Embodiment 1 FIG. 2 is a block diagram showing the configuration of Embodiment 1 of the position loop stabilization compensator of the present invention. In FIG. 2, reference numeral 803 denotes a second-order low-pass filter serving as a phase adjusting unit. The difference between the speed command v _r and the load speed signal v _L obtained by differentiating the load position signal y _L by the differentiation processing unit 801 is calculated by a low-pass filter 803.
To enter. Low-pass filter 80 at oscillation frequency
The parameters of the low-pass filter 803 are set so that the output signal of No. 3 is delayed by 90 ° from the input signal. The output signal of the low-pass filter 803 is converted into an appropriate compensation gain K _{f
Is multiplied} to obtain a speed command correction signal v _rh . Note that reference numeral 808 denotes a subtraction unit. As described above, the speed command basic signal v _rb
Is canceled by the speed command correction signal v _rh with respect to the resonance signal of the position loop included in the above, the position loop gain can be increased. Furthermore, since no integral term is included, no steady-state error remains. That is, highly accurate positioning can be performed in a short time. Embodiment 2 FIG. 3 is a block diagram showing the configuration of Embodiment 2 of the position loop stabilization compensator of the present invention. In FIG. 3, reference numeral 804 denotes a band-pass filter composed of a second-order low-pass filter and a first-order high-pass filter as phase adjusting means. Speed command v bandpass filter 80 the difference between _r and the load speed signal v _L of the load position signal y _L and differential operation by the differential processing unit 801
Enter 4 The parameters of the bandpass filter 804 are set so that the output signal of the bandpass filter 804 has a phase delay of 90 ° from the input signal at the oscillation frequency. The output signal of the bandpass filter 804 is _multiplied by an appropriate compensation gain _Kf to obtain a speed command correction signal v _rh . In this compensation method, the number of high-pass filters is increased as compared with the compensation method of FIG. 2, so that the influence of a low-frequency disturbance signal appearing in a load position signal such as a base swing can be reduced. Third Embodiment FIG. 4 is a block diagram showing a configuration of a position loop stabilization compensator according to a third embodiment of the present invention. In FIG. 4, reference numeral 805 denotes a band-pass filter including a first-order low-pass filter and a first-order high-pass filter serving as phase adjusting means, and 806 denotes an integration processing unit. The difference between the signal obtained by integrating the speed command v _r by the integration processing unit 806 and the load position signal y _L is input to the band-pass filter 805. 809 is a subtraction means. The band-pass filter 8 is controlled so that the output signal of the band-pass filter 805 has the same phase as the input signal at the oscillation frequency.
05 parameters are set. Bandpass filter 80
5 is _multiplied by an appropriate compensation gain _Kf to obtain a speed command correction signal v _rh . This compensation method can obtain the same control effect as the compensation method of FIG. 3, but the configuration of the compensator and adjustment of parameters are simple because the low-pass filter constituting the band-pass filter is of the first order.

[0006]

As described above, according to the present invention, the position loop gain can be increased since the resonance signal of the position loop included in the speed command basic signal is canceled by the speed command correction signal. Furthermore, since no integral term is included, no steady-state error remains. That is, highly accurate positioning can be performed in a short time.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a full-closed control system combining a position loop stabilization compensator;

FIG. 2 is a diagram illustrating a position loop stabilization compensator according to a first embodiment of the present invention;
Block diagram showing the configuration of

FIG. 3 is a diagram illustrating a position loop stabilization compensator according to a second embodiment of the present invention.
Block diagram showing the configuration of

FIG. 4 is a diagram illustrating a position loop stabilization compensator according to a third embodiment of the present invention.
Block diagram showing the configuration of

FIG. 5 is a block diagram showing a configuration of a conventional position loop stabilization compensator;

FIG. 6 is a block diagram showing a configuration of a normal full-closed control system;

[Explanation of symbols]

Reference Signs List 1 position control unit 2 speed control unit 3 motor 4 load (machine movable unit) 5 position detection unit (encoder) 6 position detection unit (linear scale) 7, 801 differential processing unit 8 position loop stabilization compensation unit 802 gain setting unit 803 Secondary low-pass filter 804 Band-pass filter composed of a secondary low-pass filter and a primary high-pass filter 805 Band-pass filter composed of a primary low-pass filter and a primary high-pass filter 806, 807 Integration processing unit 808, 809 Subtraction unit 9 Addition unit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masaru Nakano 2-1 Kurosaki Castle Stone, Yawatanishi-ku, Kitakyushu-shi, Fukuoka F-term (reference) 5H303 AA01 AA04 BB01 BB06 CC01 CC03 CC07 DD01 EE03 EE07 FF06 GG13 HH02 HH07 JJ02 KK02 KK04 KK14 KK17 KK29 MM05

Claims (3)

[Claims] 1. A speed control is performed based on a motor speed signal obtained by differentiating a rotational position signal of a motor, and a position control is performed based on a load position signal from a position detector attached to a load driven by the motor. In the load position control device, a differential operation means for differentiating the load position signal and outputting a load speed signal, a subtraction means for calculating a difference between the load speed signal and a speed command signal, and a difference output by the subtraction means Phase adjusting means for performing phase adjustment by inputting a signal to a low-pass filter, proportional gain means for inputting an output signal of the phase adjusting means, and adding the output signal of the proportional gain means and the speed command signal to form a new signal. A position control device comprising: an adding unit that outputs a speed command signal. 2. The position control device according to claim 1, wherein the phase adjustment unit performs phase adjustment by inputting a difference signal output from the subtraction unit to a band-pass filter. 3. Speed control is performed based on a motor speed signal obtained by differentiating a rotational position signal of the motor, and position control is performed based on a load position signal from a position detector attached to a load driven by the motor. In a load position control device, an integration operation means for integrating an operation of a speed command signal, a subtraction means for calculating a difference between the load position signal and an integration signal output from the integration operation means, and a difference output from the subtraction means. Phase adjusting means for performing phase adjustment by inputting a signal to a band-pass filter, proportional gain means for inputting an output signal of the phase adjusting means, and adding the output signal of the proportional gain means and the speed command signal to obtain a new signal. A position control device comprising: an adding unit that outputs a speed command signal.