JPH11102223A - Servo motor control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a position shift corresponding to stagnating pulses from being generated when switching between speed control and position control is controlled by saving the stagnating pulses present in a servo driver in the timing of the control over the switching between the speed control and position control. SOLUTION: A position loop arithmetic part 24 while monitoring the state of the stagnating pulses ΔP calculates a command value for the rotating speed of a motor. When a positioning controller 10 outputs a switching signal for the speed control and position control, the stagnating pulses ΔP of a stagnating pulse arithmetic part 23 are reset. To save the stagnating pulses ΔP, an instantaneous value E of a position detection part 22 is written in a counter 21 and the value E+ΔP obtained by adding the stagnating pulses ΔP to the instantaneous value E of the position detection part 22 is written to the position detection part 22. Consequently, even when the switching between the speed control and position control is controlled, there is not a shift corresponding to the stagnating pulses ΔP and accurate positioning control is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse train command type servo motor control system used for controlling a manipulator or the like, and more particularly to an improvement for improving positioning accuracy when switching between speed control and position control.

[0002]

2. Description of the Related Art FIG. 2 is a block diagram showing the configuration of a conventional motor control system. In the figure, a positioning control device 1
Reference numeral 0 denotes a pulse train command type control device suitable for driving a pulse motor or the like. The servo driver 20 receives the pulse train signal sent from the positioning control device 10 and supplies a drive signal by speed servo to the controlled motor M.
The rotation angle sensor 30 is an encoder that measures the rotation angle of the controlled motor M, and the measured value is fed back to the servo driver 20.

FIG. 3 is a diagram for explaining switching control between speed control and position control. The vertical axis represents the pulse train output frequency, and the horizontal axis represents time. At time A, motor M is started and at time B
, The pulse train output frequency reaches a constant value fcnt, and the rotation speed of the motor M becomes a constant value. At time C, when the rotation angle of the motor M reaches a desired value, switching control between speed control and position control is performed. That is, positioning is performed by setting a rotation angle from the time C until the motor M stops. The rotation angle for positioning corresponds to the area S of the region indicated by oblique lines in the figure.

FIG. 4 is a structural block diagram for explaining the servo driver 20 in detail. The counter 21 counts the pulse train signal sent from the positioning control device 10. The position detection unit 22 obtains an instantaneous value of the rotation angle of the motor M from the measurement value of the rotation angle sensor 30. Accumulation pulse calculator 23
Calculates the accumulated pulse ΔP, which is the difference between the integrated value D of the counter 21 and the instantaneous value E of the position detector 22. ΔP = DE (1) The position loop calculation unit 24 calculates the command value of the rotation speed of the motor while considering the state of the accumulated pulse. For this reason, the integrated value D of the counter 21 and the instantaneous value E of the position detector 22 always operate in a state where the accumulated pulse ΔP exists. At the time of stop, the integrated value D of the counter 21 is
And the instantaneous value E of the position detector 22 match.

[0005]

However, according to the method of calculating the command value of the rotational speed of the motor from the amount of accumulated pulses, when switching control between speed control and position control is performed, the amount of accumulated pulses is reduced. However, there was a problem that it was only shifted. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a servomotor control system capable of preventing occurrence of a displacement corresponding to a pool pulse even when switching between speed control and position control.

[0006]

In order to achieve the above object, a servo motor control system according to the first aspect of the present invention comprises a positioning control device for switching between speed control and position control, and a positioning control device for controlling the switching. A servo driver 20 that inputs a pulse train signal sent from the device and supplies a drive signal by speed servo to a controlled motor M, and a rotation angle sensor 30 that measures the rotation angle of the controlled motor and feeds back to the servo driver. A servo motor control system comprising: a storage controller that stores a pool pulse existing in the servo driver at a timing when the positioning control device performs switching control between speed control and position control.

According to the first aspect of the present invention, the accumulated pulses existing in the servo driver are stored at the timing when the positioning control device performs the switching control between the speed control and the position control. According to the method of calculating the command value of the rotation speed of the motor, even when switching control between speed control and position control is performed, accurate positioning control is performed without being shifted by the accumulated pulse.

Here, the specific configuration of the servo driver is determined by using a counter 21 for integrating the pulse train signal sent from the positioning control device, and a motor for controlling the controlled motor based on the measurement signal of the rotation angle sensor. A position detection unit 22 for obtaining an instantaneous value of the rotation angle, a pool pulse calculation unit 23 for obtaining a deviation between the integrated value of the counter and the instantaneous value of the position detection unit,
The servo driver includes a position loop calculator 24 that sends a command value of the rotation speed to the controlled motor in accordance with the accumulated pulse. The accumulated pulse in the servo driver is calculated by the integrated value of the counter and the instantaneous value of the position detector. The deviation of Then
This is a specific configuration of a method of calculating a command value of the rotation speed of the motor from the amount of accumulated pulses.

Next, a specific configuration of the servo driver is changed to a switching signal receiving section 25 for detecting a switching signal for speed control and position control output from the positioning control device.
And reading the integrated value of the counter and the instantaneous value of the position detector when the switching signal is received, writing the instantaneous value of the position detector in the counter, and writing the instantaneous value of the position detector in the position detector. And a correction amount setting unit 26 for writing a value obtained by adding the accumulated pulse to the control signal. Then, the method of calculating the command value of the rotation speed of the motor from the amount of accumulated pulses is used. Even when switching control between speed control and position control is performed, accurate positioning control is performed without being shifted by the accumulated pulses. Can be realized.

In this case, the correction amount setting section 26 reads the integrated value of the counter and the instantaneous value of the position detecting section when the switching signal is received, and stores the integrated value of the counter in the counter. The same operation as in claim 3 can be performed by writing a value obtained by adding the accumulated pulse to the position detecting section and writing a value obtained by adding the accumulated pulse to the instantaneous value of the position detecting section to the position detecting section.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a configuration block diagram showing one embodiment of the present invention. In FIG. 1, components having the same functions as those in FIGS. 3 and 4 are denoted by the same reference numerals, and description thereof is omitted. In the figure, the servo driver 20 has a switching signal receiving unit 25 and a correction amount setting unit 26. The switching signal receiving unit 25 detects a switching signal for speed control and position control output from the positioning control device 10. The correction amount setting unit 26 reads the integrated value D of the counter 21 and the instantaneous value E of the position detection unit 22 when the switching signal is received. Then, the instantaneous value E of the position detector 22 is written in the counter 21, and the value E + ΔP obtained by adding the accumulated pulse ΔP to the instantaneous value E of the position detector 22 is written in the position detector 22.

In the apparatus configured as described above, the position loop calculator 24 calculates the command value of the motor rotation speed while considering the state of the accumulated pulse ΔP. Here, when the positioning control device 10 outputs a switching signal for speed control and position control, the accumulated pulse ΔP of the accumulated pulse calculation unit 23 is reset. Therefore, the accumulated pulse Δ
To store P, the counter 21 has a position detecting unit 22
Is written to the position detector 22, and the position detector 2
E + ΔP obtained by adding the accumulated pulse ΔP to the instantaneous value E of 2
Write. In this case, the starting point of the motor rotation angle is D, and the positioning accuracy is improved.

In the above embodiment, the correction amount setting unit 26 is configured to read the integrated value D of the counter 21 and the instantaneous value E of the position detection unit 22 when the switching signal is received. The present invention is not limited to this, and the configuration may be such that the accumulated pulse ΔP of the accumulated pulse calculation unit 23 is read, and the integrated value D + ΔP of the counter 21 and the instantaneous value E + ΔP of the position detection unit 22 are calculated.

[0014]

As described above, according to the first aspect of the present invention, the accumulated pulses existing in the servo driver are stored at the timing when the positioning control device performs the switching control between the speed control and the position control. Therefore, according to the method of calculating the motor rotation speed command value from the amount of accumulated pulses, even when switching between speed control and position control, accurate positioning is achieved without displacement by the accumulated pulses. Control is exercised.

Here, the specific configuration of the servo driver is determined by using a counter 21 for integrating the pulse train signal sent from the positioning control device, and a motor for controlling the controlled motor based on the measurement signal of the rotation angle sensor. A position detection unit 22 for obtaining an instantaneous value of the rotation angle, a pool pulse calculation unit 23 for obtaining a deviation between the integrated value of the counter and the instantaneous value of the position detection unit,
The servo driver includes a position loop calculator 24 that sends a command value of the rotation speed to the controlled motor in accordance with the accumulated pulse. The accumulated pulse in the servo driver is calculated by the integrated value of the counter and the instantaneous value of the position detector. The deviation of Then
This is a specific configuration of a method of calculating a command value of the rotation speed of the motor from the amount of accumulated pulses.

Further, a specific configuration of the servo driver may be changed to a switching signal receiving section 25 for detecting a switching signal for speed control and position control output from the positioning control device.
And reading the integrated value of the counter and the instantaneous value of the position detector when the switching signal is received, writing the instantaneous value of the position detector in the counter, and writing the instantaneous value of the position detector in the position detector. And a correction amount setting unit 26 for writing a value obtained by adding the accumulated pulse to the control signal. Then, the method of calculating the command value of the rotation speed of the motor from the amount of accumulated pulses is used. Even when switching control between speed control and position control is performed, accurate positioning control is performed without being shifted by the accumulated pulses. Is made. In claim 4, another configuration of the correction amount setting unit 26 that realizes the same function is described.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention.

FIG. 2 is a configuration block diagram of a conventional motor control system.

FIG. 3 is a diagram illustrating switching control between speed control and position control.

FIG. 4 is a diagram illustrating aspects of a comparison operation instruction.

[Explanation of symbols]

 Reference Signs List 10 Positioning control device 20 Servo driver 30 Rotation angle sensor M Servo motor

Claims (4)

[Claims] 1. A positioning control device (10) for switching between speed control and position control, and a pulse train signal sent from the positioning control device is input, and a drive signal by a speed servo is supplied to a controlled motor M. And a rotation angle sensor (30) that measures the rotation angle of the controlled motor and feeds it back to the servo driver, wherein the positioning control device performs speed control. A servo motor control system, wherein a pool pulse existing in the servo driver is stored at a timing of switching control of position control. 2. A counter for accumulating a pulse train signal sent from a positioning control device.
A position detector (22) for obtaining an instantaneous value of the rotation angle of the controlled motor from a measurement signal of the rotation angle sensor; and a pooling pulse calculator (22) for obtaining a deviation between the integrated value of the counter and the instantaneous value of the position detector. 23), and a position loop calculating section (24) for sending a command value of the rotation speed to the controlled motor in response to the accumulated pulse. The accumulated pulse existing in the servo driver is calculated by multiplying the accumulated value of the counter by 2. The servomotor control system according to claim 1, wherein the deviation is an instantaneous value deviation of the position detector. A switching signal receiving section for detecting a switching signal between the speed control and the position control output by the positioning control device; and an integrated value of the counter at the time of receiving the switching signal. A correction amount setting unit (26) which reads the instantaneous value of the position detection unit, writes the instantaneous value of the position detection unit in the counter, and writes a value obtained by adding the accumulated pulse to the instantaneous value of the position detection unit in the position detection unit. 3. The servo motor control system according to claim 2, wherein: 4. A switching signal receiving section (25) for detecting a switching signal for speed control and position control output by the positioning control device, and an integrated value of the counter at the time of receiving the switching signal. Reads the instantaneous value of the position detector, writes a value obtained by adding the accumulated pulse to the integrated value of the counter to the counter, and writes a value obtained by adding the accumulated pulse to the instantaneous value of the position detector to the position detector. 3. The servo motor control system according to claim 2, further comprising an amount setting unit.