JP2006271100A - Method of detecting abnormality in inertial value of load, and controller using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the vibration, etc. in actual operation by detecting the abnormality of an inertial value before operating a motor even if there is abnormality in the inertial value of a load set in a controller. <P>SOLUTION: Simulated turbulent torque 9 is added to a torque command 10 to be given to a motor 6, and the specified detection level of the vibration is detected with a vibration detecting means 1. If there is no response on a detection level or over, the simulated turbulent torque 9 is enlarged or the value of the detection level is lowered. The magnitude of the simulated turbulent torque 9 and the results of the detection level of vibration are compared to judge whether the load inertial value is abnormal or not. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the servo control device for driving the servo motor according to the present invention, when there is an abnormality in the inertia value set by the user or the like, the abnormality is detected before the motor is normally operated to prevent the occurrence of the abnormality during the operation. On how to do.

In the conventional servo control device, there is no prior detection method when the set inertia value is abnormal, etc., and overload and overspeed etc. are detected by vibration etc. when the load is actually operated, Was judged abnormal. For example, as in Patent Document 1, a motor is operated, and the motor is operated by calculating an optimum load inertia from the acceleration time of the motor and a torque obtained by integrating the time. Alternatively, as in Patent Document 2, the motor is operated and the load inertia is estimated using the estimated disturbance torque value and acceleration information obtained from the disturbance estimation observer.
Japanese Patent Laid-Open No. 2002-153088 JP-A-11-313495

However, when the inertia value is abnormal in the conventional technique, the motor is operated to some extent to detect vibrations and the like, and the abnormality of the inertia value is judged. there were. Further, once the motor is operated while the initial inertia value is set abnormally, the control system becomes unstable, so that acceleration / deceleration is involved instead of constant acceleration. As a result, the motor does not operate normally, and there is another problem that the control device cannot correctly estimate the inertia value.
This proposal was made in view of such problems, and detects an abnormality in the inertia value before operating the motor even if the inertia value is abnormal, thereby preventing vibrations and the like in actual operation. With the goal.

In order to solve the above problems, the present invention is as follows.
According to a first aspect of the present invention, there is provided a load inertia value abnormality detection method for a control device that determines whether or not a load inertia value set by a servo control device that drives a servo motor is abnormal. A simulated disturbance torque exceeding the magnitude vibration level is added to the torque command, and the vibration level of the control system is detected by the vibration detection means from the difference between the estimated speed from the motor and load model and the speed of the servo motor, and the vibration By comparing the level and the magnitude of the simulated disturbance torque, the load inertia value abnormality detection method for determining whether or not the set load inertia value is abnormal is adopted.
According to a second aspect of the present invention, in the comparison, when the simulated disturbance torque is larger than a predetermined value and the vibration level detected by the vibration detecting unit is larger than a predetermined value, a preset load inertia value is obtained. 2. The load inertia value abnormality detection method according to claim 1, wherein the abnormality is determined to be abnormal.
According to a third aspect of the present invention, in the comparison, when the simulated disturbance torque is smaller than a predetermined value and the vibration level detected by the vibration detecting means is larger than a predetermined value, a preset load inertia value is obtained. 2. The load inertia value abnormality detection method according to claim 1, wherein the abnormality is determined to be abnormal.
According to a fourth aspect of the present invention, in the comparison, when the simulated disturbance torque is smaller than a predetermined value and the vibration level detected by the vibration detecting means is larger than the predetermined value, the load inertia value is lowered and the vibration is reduced. The load inertia value abnormality detection method according to claim 1, wherein if the level becomes smaller, the set load inertia value is determined to be abnormal.
According to a fifth aspect of the present invention, in the method for detecting the load inertia value of the control device for determining whether or not the load inertia value set by the servo control device for driving the servo motor is abnormal, the vibration means has a predetermined magnitude. A simulated disturbance torque exceeding the vibration level is added to the torque command, and the vibration level of the control system is detected by the vibration detection means from the difference between the estimated speed from the motor and load model and the speed of the servo motor, and the motor is When position control is performed, the position loop gain is compared with the speed loop gain including the load inertia value. When the speed loop gain is low or when the vibration continues for a predetermined time or longer, the previous load inertia value set is set. The load inertia value abnormality detection method for determining that is abnormal.
According to a sixth aspect of the present invention, there is provided a servo control device for driving a servomotor, an excitation means for applying a simulated disturbance torque exceeding a predetermined vibration level to a torque command, and an estimated speed from a motor and load model. Whether the load inertia value set by comparing the vibration level with the magnitude of the simulated disturbance torque is abnormal, and vibration detection means for detecting the vibration level of the control system from the difference between the servo motor speed and the servo motor speed And a determining unit that determines whether or not.
According to a seventh aspect of the present invention, when the simulated disturbance torque is larger than a predetermined value and the vibration level detected by the vibration detecting means is larger than a predetermined value, the determination means has a preset load inertia value. The control device according to claim 1, wherein it is determined that is abnormal.
According to an eighth aspect of the present invention, when the simulated disturbance torque is smaller than a predetermined value and the vibration level detected by the vibration detecting unit is larger than a predetermined value, the determination unit has a preset load inertia value. The control device according to claim 1, wherein it is determined that is abnormal.
According to a ninth aspect of the present invention, when the simulated disturbance torque is smaller than a predetermined value and the vibration level detected by the vibration detecting unit is larger than a predetermined value, the determination unit decreases the load inertia value, The control device according to claim 1, wherein if the vibration level becomes small, the set load inertia value is determined to be abnormal.
According to a tenth aspect of the present invention, there is provided a servo control apparatus for controlling a position for driving a servo motor, comprising: excitation means for adding a simulated disturbance torque exceeding a predetermined vibration level to a torque command; and a motor and load model. The vibration detection means for detecting the vibration level of the control system from the difference between the estimated speed of the servo motor and the speed of the servo motor is compared with the speed loop gain including the position loop gain and the load inertia value, and the speed loop gain is low. Or when the vibration detected by the vibration detection means continues for a predetermined time or more, the control device is provided with a determination means for determining that the set load inertia value is abnormal.

  According to the first, second, third, fourth, and fifth aspects of the invention, it is possible to detect an abnormality in the load inertia value before operating the motor and prevent vibration during operation in advance. is there.

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

FIG. 1 is a part of a configuration example of a control device using the present invention. FIG. 2 is a control block diagram of FIG. FIG. 4 is a measurement timing chart of the speed command, speed, torque waveform and vibration level when the motor is normally operated in FIG.
In FIG. 1, 1 is a vibration detection means, 2 is a microcomputer, 3 is a current amplifier, 4 is a base drive circuit, 5 is a power transistor module, 6 is a motor, 7 is an excitation means, 8 is an encoder, and 9 is a simulated disturbance. Torque 10 is a torque command. Although various functions and means (not shown) are built in the actual control device, FIG. 1 shows only the components related to the present invention.
In FIG. 2, 21 indicates a position loop gain, 22 indicates speed control, 23 indicates a motor, and 24 indicates integration.
Next, the operation of FIG. 1 will be described. First, the microcomputer 2 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 6 is controlled by driving the power transistor 5 through the base drive drive circuit 4 with the output current command or current control output. Here, the vibration detection means 1 detects vibration when the vibration component included in the torque command or the motor speed signal exceeds a predetermined level (hereinafter referred to as a detection level). This detection level is determined in advance, for example, or from the amplitude level of vibration when the control system is stopped in a stable state.
Next, the load inertia value abnormality detection method according to the present invention will be described. In the abnormality detection, as shown in FIG. 2, first, a simulated disturbance torque is applied to the torque command with a low gain, and it is confirmed whether or not the vibration detection means 1 in FIG. 1 detects the detection level of vibration. In FIG. 2, 21 indicates a position loop gain, 22 indicates speed control, 23 indicates a motor, and 24 indicates integration. Here, as shown in FIG. 6, if no vibration is detected by the vibration detecting means 1, the simulated disturbance torque is gradually increased. Increase the simulated disturbance torque until vibration is detected, or lower the vibration detection level.
If the load inertia value and the inertia value used in the model match, the response is close, so the difference between the model speed and the actual speed is small because the estimated value is correct. Since the responses do not match as shown in the figure, the difference between the model speed and the actual speed becomes large. When the load inertia increases, the simulated disturbance torque increases as shown in FIG. However, on the contrary, the vibration amplitude becomes smaller because it is stabilized by the load inertia as shown in FIG.
A specific procedure for detecting abnormality of the load inertia value is as shown in FIG.
In FIG. 9, first, the gain of the control system such as the position loop and the speed loop is set to a low gain as indicated by 91, and the operation is performed as shown in FIG. FIG. 3 is a block diagram for detecting the difference between the estimated speed and the speed of the present invention. In FIG. 3, 31 is a speed control, 32 is a motor, and 33 is a motor and load model. In FIG. 3, the maximum value of the vibration amplitude of the torque in the normal operation is detected.
Next, the simulated disturbance torque is gradually increased to the torque command τref of FIG. Confirm that the response such as deviation or speed is above a certain level and above the detection level. Here, if there is no response exceeding the detection level, it is considered that the applied simulated disturbance torque has not exceeded the mechanical load, and the simulated disturbance torque is increased. This detection level is set to be twice the maximum value of the vibration amplitude during normal operation in 91 of FIG. If the vibration level is not detected even when the simulated disturbance torque is increased to a certain level, the value of the detection level is lowered. As described above, the magnitude of the simulated disturbance torque and the detection level of the response are adjusted.
Next, as shown at 94 in FIG. 9, the adjusted result is determined. That is, when the adjusted vibration amplitude is larger than the detection level, the simulated disturbance torque is compared at 95 in FIG. Here, the relationship between the magnitude of the simulated disturbance torque and the load inertia is proportional as shown in FIG. Let them compare. That is, when the simulated disturbance torque given as 97 in FIG. 9 is larger than a predetermined value, the load inertia value is small although it is large, and the set load inertia value is too small. When the simulated disturbance torque is small as indicated by 98 in FIG. 9, the load inertia value is small but large, so the set load inertia value is too large.
In addition, when the simulated disturbance torque is neither large nor small as in 99 of FIG. 9, the load inertia value is not an appropriate value. In this case, for example, the load amplitude value is increased or decreased to increase or decrease the vibration amplitude. Whether or not the load inertia value is appropriate is determined based on whether or not it becomes.
The balance is confirmed at 100 in FIG. For example, Kp × 4 <Kv × J ′ / J is determined. Here, Kp is a position loop gain, Kv is a velocity loop gain, J is a load inertia setting value, and J ′ is a load inertia of the model. Although 4 in this equation is a stability coefficient, it may be increased with a margin. That is, when it is not large, the balance is abnormal. Alternatively, if there is vibration above a certain level even after a certain period of time, a balance abnormality is assumed. A certain level of vibration is, for example, 1.5 times the maximum value of vibration amplitude during normal operation.
As described above, the abnormality of the load inertia value can be detected.
In FIG. 1, the vibration detecting means 1 is described separately from the microcomputer 2, but the detection may be performed in the microcomputer 2.

Part of a configuration example of a control device using the present invention Control block diagram of FIG. Detection block diagram of estimated speed and difference in speed of the present invention Measurement timing diagram of speed command, speed, torque waveform and vibration level during normal operation Timing chart of vibration generation and inertia detection Relationship diagram between inertia value and speed difference Relationship diagram between load inertia value and simulated disturbance torque Relationship diagram between load inertia value and vibration amplitude Schematic flowchart for detecting the load inertia value of the present plan

Explanation of symbols

1 Vibration detection means 2 Microcomputer 6 Motor 7 Excitation means 9 Simulated disturbance torque 10 Torque command

Claims (10)

In the load inertia value abnormality detection method of the control device that determines whether or not the load inertia value set in the servo control device that drives the servo motor is abnormal,
A simulated disturbance torque exceeding a predetermined vibration level is added to the torque command by the vibration means,
The vibration detection means detects the vibration level of the control system from the difference between the estimated speed from the motor and load model and the speed of the servo motor,
A load inertia value abnormality detection method comprising: determining whether or not a set load inertia value is abnormal by comparing the vibration level and the magnitude of the simulated disturbance torque.   2. The comparison determines that a preset load inertia value is abnormal when the simulated disturbance torque is larger than a predetermined value and the vibration level detected by the vibration detecting unit is larger than a predetermined value. The load inertia value abnormality detection method described.   2. The comparison determines that a preset load inertia value is abnormal when the simulated disturbance torque is smaller than a predetermined value and the vibration level detected by the vibration detecting unit is larger than a predetermined value. The load inertia value abnormality detection method described. The comparison is set when the simulated disturbance torque is smaller than a predetermined value and the vibration level detected by the vibration detecting means is larger than the predetermined value, the load inertia value is lowered, and the vibration level becomes smaller. 2. The load inertia value abnormality detection method according to claim 1, wherein the load inertia value is determined to be abnormal. In the detection method of the load inertia value of the control device for determining whether or not the load inertia value set in the servo control device that drives the servo motor is abnormal,
A simulated disturbance torque exceeding a predetermined vibration level is added to the torque command by the vibration means,
The vibration detection means detects the vibration level of the control system from the difference between the estimated speed from the motor and load model and the speed of the servo motor,
When the position of the motor is controlled, the position loop gain is compared with the speed loop gain including the load inertia value, and when the speed loop gain is low or the vibration continues for a predetermined time or more, the previous period set A load inertia value abnormality detection method for determining that the load inertia value is abnormal. In the servo control device that drives the servo motor,
Vibration means for applying a simulated disturbance torque exceeding a predetermined magnitude of vibration level to the torque command;
Vibration detecting means for detecting the vibration level of the control system from the difference between the estimated speed from the motor and load model and the speed of the servo motor;
And a determination unit configured to determine whether or not the load inertia value set by comparing the vibration level with the magnitude of the simulated disturbance torque is abnormal.   The determination means determines that a preset load inertia value is abnormal when the simulated disturbance torque is larger than a predetermined value and the vibration level detected by the vibration detection means is larger than a predetermined value. The control device according to 1.   The determination means determines that a preset load inertia value is abnormal when the simulated disturbance torque is smaller than a predetermined value and the vibration level detected by the vibration detection means is larger than a predetermined value. The control device according to 1. The discriminating means is set when the simulated disturbance torque is smaller than a predetermined value and the vibration level detected by the vibration detecting means is larger than the predetermined value, the load inertia value is lowered, and the vibration level becomes smaller. The control device according to claim 1, wherein the load inertia value that has been determined is abnormal. In the servo control device that controls the position of driving the servo motor,
Vibration means for applying a simulated disturbance torque exceeding a predetermined magnitude of vibration level to the torque command;
Vibration detecting means for detecting the vibration level of the control system from the difference between the estimated speed from the motor and load model and the speed of the servo motor;
The position loop gain is compared with the speed loop gain including the load inertia value. When the speed loop gain is low or when the vibration detected by the vibration detecting means continues for a predetermined time or more, the set A control apparatus comprising: a determination unit that determines that the load inertia value is abnormal.

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