JP2006271116A - Servo controller and method of extracting maximum gain of servo controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress vibration by measuring and judging the situation immediately even when a servo controller for driving a servo motor vibrates largely during rotation. <P>SOLUTION: A vibration detecting means detects the vibration during operation of a machine that becomes the load of the servo motor, and a torque command output means outputs the torque command of a phase difference of 90° to vibration frequency thereby suppressing the above vibration. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a servo control device that detects vibration during operation and extracts a maximum gain in a control gain adjustment of a servo control device that drives a servo motor, and a method thereof.

FIG. 8 shows a configuration diagram of a conventional servo control device. In the figure, 7 is a vibrometer. Conventionally, the vibration of the machine is detected by the vibrometer 7 so that, for example, a person reduces the control gain or reduces the torque. That is, in a servo control device that drives a servo motor, when vibration is detected during operation, a person decreases the control gain or decreases the torque.
Further, the gain is increased to oscillate, and the gain when oscillated is set to the maximum value (for example, see Patent Document 1). In other words, adjustments are made such that oscillation is detected and the gain is set to the maximum value in consideration of the machine.
JP-A-2-261108 (pages 27-33, FIG. 7)

However, in the conventional method, when vibration is detected during operation, the vibration can be suppressed by lowering the control gain or reducing the torque, but control is almost impossible, and the machine moves due to disturbance, etc. There was a problem.
The present invention has been made in view of such various problems. When the machine oscillates during operation, only vibration is suppressed, and then control can be continued and operation can be continued. An object of the present invention is to provide a servo control device capable of performing the above.

In order to solve the above problem, the present invention is configured as follows.
The invention described in claim 1 is provided with a vibration detection means for detecting the vibration of the control system, and a torque command output means for outputting a torque command, wherein the vibration detection means is a servo control device for driving a servo motor. Vibration is detected during operation of a machine serving as a load of the servo motor, and the torque command output means outputs a torque command having a phase difference of 90 degrees of the vibration frequency, thereby suppressing the vibration. It is.
According to a second aspect of the present invention, there is provided a servo control device for driving a servo motor, comprising: vibration detection means for detecting vibration of the control system; and torque command output means for outputting a torque command. Vibration is detected during operation of the machine serving as the load of the servo motor, the speed is estimated by a machine model representing the servo motor and the servo motor load, and the torque command output means is the vibration of the estimated speed feedback. The vibration is suppressed by outputting a torque command having a phase difference of 90 degrees in frequency.
The invention described in claim 3 is characterized in that an observer is used instead of the machine model.
According to a fourth aspect of the present invention, there is provided a servo control device comprising: vibration detection means for detecting vibration of a control system; and torque command output means for outputting a torque command. When vibration is detected during operation of a machine serving as a load of the servo motor, the vibration is suppressed by lowering the control gain.
The invention described in claim 5 is characterized in that the vibration is suppressed by inserting an observer instead of lowering the control gain.
According to a sixth aspect of the present invention, there is provided a servo control device for driving a servo motor, comprising: vibration detection means for detecting vibration of a control system; and torque command output means for outputting a torque command, wherein the vibration detection means When vibration is detected during operation of a machine serving as a load of the servo motor, the torque command output means outputs a torque command having a phase difference of 90 degrees of the vibration frequency, thereby suppressing the vibration. Is.
According to a seventh aspect of the present invention, there is provided a servo control device for driving a servo motor, comprising: vibration detection means for detecting vibration of a control system; and torque command output means for outputting a torque command, wherein the vibration detection means When vibration is detected during the operation of the machine serving as the load of the servo motor, the speed is estimated by a machine model representing the motor and the load of the motor, and the torque command output means is used for feedback of the estimated speed. The vibration is suppressed by outputting a torque command having a phase difference of 90 degrees of the vibration frequency.
The invention described in claim 8 is characterized in that an observer is used instead of the machine model.

  According to the present invention, when vibration is detected during the operation for adjustment, the vibration can be suppressed by a torque command having a phase difference of 90 degrees of the vibration frequency. There is an effect that vibration can be suppressed by measuring and judging.

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

  FIG. 1 shows a block diagram of a specific embodiment of the present invention. In the figure, 11 is a microcomputer, 12 is a current amplifier, 13 is a base drive circuit, 14 is a power transistor module, 15 is a motor, 16 is a load machine, 17 is vibration detection means, and 18 is frequency analysis means.

The operation of the above configuration will be described with reference to the control block diagram of FIG. 2 and the timing diagram of FIG.
First, the microcomputer 11 receives commands such as position and speed from an external controller or the like. For example, in the case of a speed command, speed control is performed, and the motor 15 is controlled by driving the power transistor 14 through the base drive drive circuit 13 with the output current command or current control output. Here, the vibration detection means 17 detects vibration when the vibration component included in the torque command or the motor speed signal exceeds a predetermined level. That is, in the block diagram shown in FIG. 3, vibration is detected when the speed obtained by subtracting the estimated speed ω ₀ from the motor and load model (mechanical model) 33 and the actual speed ω exceeds a certain detection level.
In the block diagram shown in FIG. 4, the vibration may be detected when the speed obtained by subtracting the estimated speed ωob from the observer 47 and the actual speed ω exceeds a certain detection level.

  Here, in order to explain the basic concept of the present invention, the situation where the control system oscillates will be described. When vibration occurs in the control system due to mechanical resonance or the like in the absence of a load such as machine friction, the control loop gain causes the vibration to rapidly increase and shift to the oscillation state, making it difficult to stop the vibration. It becomes. The load of the machine such as friction has a function of suppressing vibration by consuming energy. In an unstable state where there is a mechanical load but the gain is high and the vibration is likely to occur, the load can be varied to induce the vibration, or the induced vibration can be stopped. However, if the control gain is extremely high or increased, the vibration also increases. In this case, it can be quickly suppressed by applying a torque to be suppressed.

  A specific method for detecting the maximum gain is as follows. First, in the control block diagram shown in FIG. 3, the vibration detection means 17 detects vibration at about twice the level during normal operation, for example. When normal operation is performed as shown in FIG. 5 and the control gain is increased at the timing as shown in FIG. 5 and the vibration detection means 17 detects vibration, the frequency analysis means 18 simultaneously analyzes the vibration frequency, as shown in FIG. Torque command output means (not shown) applies a torque that is suppressed at a timing that matches the frequency of the 90-degree phase difference to suppress vibration. Here, the torque having a phase difference of 90 degrees may be generated through a filter or the like that delays the phase only at that frequency, for example.

  This detection method will be described with reference to a vibration suppression flow shown in FIG. First, in step 1, the vibration detection means 17 confirms whether or not the vibration level is exceeded. Next, if it is more than a vibration level, a vibration frequency will be analyzed by the frequency analysis means 18 at step 2, and the torque which will be suppressed after the time will be applied at step 3. At this time, the control gain may be lowered at the same time in order to quickly suppress the vibration. Next, in step 4, it is confirmed whether or not the vibration is stopped by the vibration detecting means 17, and if it is stopped, the control gain at that time is stored and the process is ended.

  Note that the vibration detection 17 may be performed by the microcomputer 1. As another embodiment, the vibration detection 17 may be detected as a vibration obtained by subtracting the speed ω from the estimated speed ωob using the observer 47 as shown in FIG. . In this case, however, the frequency analysis means 18 inputs a speed obtained by subtracting the speed from the estimated speed and extracts the vibration frequency.

Configuration diagram of a specific embodiment of the present invention Control block diagram of the present invention Control block diagram for calculating the estimated speed of the present invention Control block diagram for calculating another estimated speed of the present invention Timing diagram of vibration suppression torque when vibration is generated by increasing gain Timing diagram of torque to suppress vibration Outline flowchart to suppress vibration Configuration diagram of a conventional servo controller

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Microcomputer 12 Current amplifier 13 Base drive circuit 14 Power transistor module 15 Motor 16 Machine 17 Vibration detection means 18 Frequency analysis means 21 Position loop gain 22 Speed control 23 Motor 24 Integration 31 Speed control 32 Motor 33 Motor and load model 41 Speed Control 42 Motor 43 Observer load inertia component 44 Observer speed control gain 45 Integration 46 Observer speed control integration 47 Overall observer

Claims (8)

In a servo control device that includes a vibration detection means that detects vibration of a control system and a torque command output means that outputs a torque command, and drives a servo motor,
The vibration detection means detects vibration during operation of a machine that is a load of the servo motor,
A method for extracting a maximum gain, wherein the torque is output by the torque command output means outputting a torque command having a phase difference of 90 degrees of the vibration frequency. In a servo control device that includes a vibration detection means that detects vibration of a control system and a torque command output means that outputs a torque command, and drives a servo motor,
The vibration detection means detects vibration during operation of a machine that is a load of the servo motor,
The speed is estimated by a machine model representing the servo motor and the servo motor load,
A method for extracting a maximum gain, wherein the torque command output means suppresses the vibration by outputting a torque command having a phase difference of 90 degrees of the estimated vibration frequency of the speed feedback. 3. The maximum gain extraction method according to claim 2, wherein an observer is used instead of the machine model. In a servo control device that includes a vibration detection means that detects vibration of a control system and a torque command output means that outputs a torque command, and drives a servo motor,
When the vibration detection means detects vibration during operation of the machine that is a load of the servo motor,
A method for extracting a maximum gain, wherein the vibration is suppressed by lowering a control gain. 5. The maximum gain extracting method according to claim 4, wherein the vibration is suppressed by inserting an observer instead of lowering the control gain. In the servo control device that drives the servo motor,
A vibration detection means for detecting the vibration of the control system, and a torque command output means for outputting a torque command,
When the vibration detection means detects vibration during operation of the machine that is the load of the servo motor, the torque command output means suppresses the vibration by outputting a torque command having a phase difference of 90 degrees of the vibration frequency. A servo control device characterized by that. In the servo control device that drives the servo motor,
A vibration detection means for detecting the vibration of the control system, and a torque command output means for outputting a torque command,
When the vibration detection means detects vibration during operation of a machine that is a load of the servo motor, the speed is estimated by the machine model representing the motor and the load of the motor, and the torque command output means is estimated. A servo control device that suppresses the vibration by outputting a torque command having a phase difference of 90 degrees of the vibration frequency of the feedback of the measured speed. 8. The servo control device according to claim 7, wherein an observer is used instead of the machine model.

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