JP2010146350A - Vibration suppression control device for positioning control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress vibration independently of filter phase lag. <P>SOLUTION: In a vibration suppression control device for a positioning control device including an acceleration control system using a disturbance observer 10, a low-pass filter 12 is inserted in the part of a position command, and the cutoff frequency of the low-pass filter 12 in the position command part is the frequency of a disturbance observer gain value Gdis set for the positioning control device. Another low-pass filter 14 may be inserted in the part of a velocity feed-forward command different from the position command part, and the cutoff frequency of the low-pass filter in the velocity feed-forward command part is the frequency of the disturbance observer gain value Gdis set for the positioning control device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibration suppression control device of a positioning control device, and more particularly to vibration suppression control of a motor control device used for a flexible manipulator, an XY robot, or the like.

  In general, in motor drive systems such as flexible manipulators, XY robots using ball screws, timing belts, etc., as illustrated in FIG. 1, the motor M and the load A have low rigidity in preference to weight reduction rather than rigidity. Are coupled by an elastic shaft (belt B stretched between pulleys P in the figure), a resonance system is generated, which may cause a problem of torsional vibration of the shaft.

  Since an actual resonance system has many vibration modes and natural frequencies, it is modeled as a multi-inertia resonance system as illustrated in FIG. In FIG. 2, Jm is the inertia of the motor M, Kf1, Kf2... Are spring constants, Ja1, Ja2,.

  This multi-inertia resonance system is represented by a block diagram as shown in FIG. In FIG. 3, θm is the rotation angle (motor position) of the motor M, θa is the rotation angle (load position) of the load A, T is the torque, s is the Laplace operator, subscript m is the motor, subscript a is the load, subscript dis Is a disturbance and subscript reac is a torsional reaction force.

  For such resonance suppression and disturbance suppression control, methods such as state feedback control, H∞ control, slow disturbance observer control, resonance ratio control (see Non-Patent Document 1) have been proposed.

  However, state feedback control and H∞ control require a high-speed, high-function CPU because of complicated control systems and enormous amount of calculations, and are difficult to adjust in the field. For these reasons, there is a problem in application to actual machines. On the other hand, the slow disturbance observer control and the resonance ratio control are composed of a relatively simple control system and have high practicality.

  However, in the resonance ratio control described in Non-Patent Document 1, the system is modeled as a two-inertia resonance system in which a motor and an arm are coupled by a flexible drive shaft. However, in an actual multi-inertia system, there is a problem that a high-order vibration is caused, and the effect on a high-order vibration is low.

  On the other hand, Patent Document 1 describes that a separate phase advance filter is provided in the servo system, but the configuration is complicated, requires a detailed calculation, requires a long calculation time, and is realized by an inexpensive control device. become unable. The design is complicated, and it is difficult to find a parameter with a stable response.

  In order to solve such problems, the applicant has proposed an acceleration control system using a disturbance observer 10 as shown in FIG. In the figure, C is a bearing portion.

  In FIG. 4, the positioning control system using the timing belt B is taken up, but the configuration of the control system itself is the same in the case of a ball screw or a linear motor.

  A block diagram of the disturbance observer 10 is shown in FIG. Since the disturbance observer 10 works with the characteristics of a high-pass filter with respect to the input disturbance, as shown in FIG. 6, it is possible to suppress a disturbance having a frequency lower than the disturbance observer gain Gdis. The value of the disturbance observer gain Gdis is set while observing the behavior of the positioning control device, but there is a limit to the frequency at which the disturbance observer gain Gdis can be increased due to the influence of the rigidity of the control target.

Japanese Patent No. 3381880 JP 2007-038884 A Yuki et al. “Vibration Suppression Control of Two-Inertia Resonance System by Resonance Ratio Control”, D. Vol. 113, No. 10, (pp. 1162–1169)

  However, in the actual positioning operation, since the frequency component higher than the disturbance observer gain Gdis is included in the vibration, the influence of the disturbance cannot be suppressed even if the disturbance observer is used. Therefore, there remains a problem that the control system is affected by a disturbance having a frequency higher than the disturbance observer gain Gdis.

  Although it is conceivable to use a disturbance observer and a low-pass filter in combination, normally, as shown in FIG. 7, the low-pass filter 12 is inserted into the main control loop. As described above, there is a possibility that oscillation and characteristic deterioration may occur due to the influence of the phase delay of the filter.

  The present invention has been made to solve the above-described conventional problems, and an object of the present invention is to enable suppression of vibration without being affected by the phase delay of the filter.

  The present invention relates to a vibration suppression control device for a positioning control device including an acceleration control system using a disturbance observer, and a disturbance observer gain value Gdis set for the positioning control device by inserting a low-pass filter in the position command portion. Is the cutoff frequency of the low-pass filter of the position command portion.

  In addition to the position command part, a low-pass filter is inserted in the speed feed forward command part, and the frequency of the disturbance observer gain value Gdis set for the positioning control device is set as the speed feed forward command. The cut-off frequency of the partial low-pass filter can be used.

  According to the present invention, when performing control using a disturbance observer, high-frequency components that are not removed by the disturbance observer are removed from the position command, so that it is possible to perform ideal disturbance suppression together with the disturbance observer. .

  Here, since the low-pass filter is inserted in the position command portion and is not included in the main control loop, there is no possibility that problems such as the phase delay of the filter will adversely affect the control.

  In addition, since the control method is based on a disturbance observer, it is possible to achieve robustness while having a vibration suppressing effect.

  Further, since the control system is simple and the amount of calculation is small compared to the state feedback control and H∞ control, it is not necessary to use an expensive CPU or the like. Furthermore, design and adjustment are easy.

  In particular, by inserting a low-pass filter with a cutoff frequency of the disturbance observer gain value Gdis set for the positioning control device into the position command portion, the frequency above Gdis is removed from the position command. A frequency component equal to or higher than Gdis is not included in the behavior of the apparatus, and ideal disturbance suppression can be performed.

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

  FIG. 8 shows an overall block diagram of the first embodiment of the present invention, and FIG. 9 shows a block diagram.

  The difference from FIG. 4 is that a low-pass filter (LPF) 12 is inserted in the position command portion. The cutoff frequency of the LPF 12 at this time is a disturbance observer gain value Gdis set for the positioning control device.

  In this way, by inserting the LPF 12 having the cutoff frequency of the disturbance observer gain value Gdis into the position command portion, the frequency above Gdis is removed from the position command, so the frequency above Gdis is included in the behavior of the positioning control device. The component is not included, and ideal disturbance suppression and vibration suppression can be performed.

  The difference in effect between the case where the LPF 12 having the cutoff frequency of the disturbance observer gain value Gdis is inserted in the position command portion and the case where the LPF 12 is not inserted are compared with the result of the simulation.

  The simulation parameters are shown in Table 1.

  FIG. 10 shows a case where the LPF having the cutoff frequency Gdis is not inserted, FIG. 11 shows a case where the LPF 12 is inserted in the main control loop as shown in FIG. It is a position step response when the LPF 12 is inserted.

  10 to 12, a vibration occurs during positioning in FIG. 10 and an oscillation occurs in FIG. 11. In FIG. 12, the LPF 12 having the cutoff frequency Gdis is inserted into the position command portion. Thus, it can be seen that the vibration during positioning is suppressed to be small without being affected by the phase delay of the filter.

  As described above, by inserting the LPF 12 having the cutoff frequency of the disturbance observer gain value Gdis into the position command portion, the frequency above Gdis is removed from the position command. A frequency component is not included, disturbance can be suppressed ideally, and a robust acceleration control system can be constructed.

  In addition, when using speed feedforward, LPF14 is inserted with respect to speed feedforward instruction | command like 2nd Embodiment shown in FIG. The cut-off frequency of the LPF 14 is set to the value of Gdis as with the LPF 12.

  As described above, since the LPF 14 having the cutoff frequency of the disturbance observer gain value Gdis is inserted into the speed feedforward command, the frequency higher than Gdis is removed from the speed feedforward command. The frequency component higher than Gdis is not included, and ideal disturbance suppression and vibration suppression can be performed.

  Further, the cutoff frequency of the LPFs 12 and 14 can automatically set the disturbance observer gain adjustment value Gdis as in the third embodiment shown in FIG. In the present embodiment, the LPF is inserted into both the position command unit and the speed feedforward unit, but the present invention can also be applied to the case where the LPF is inserted only into the position command unit.

  In the block diagram of the control device, P control is used for the speed calculation unit, but PI control, PD control, and PID control may be used.

  Further, when using the disturbance observer, as in the fourth embodiment shown in FIG. 15, the nominal value of the motor inertia previously proposed by the inventors in Patent Document 2 is used for the disturbance observer 10 as the actual inertia value of the motor. A method of performing phase lead compensation with a larger setting may be used in combination. This makes it possible to stabilize the higher-order pole.

The block diagram which shows an example of the application object of this invention Same model diagram Same block diagram Block diagram of a conventional control system using a disturbance observer Block diagram of disturbance observer Diagram showing frequency characteristics of disturbance observer for disturbance Block diagram of a comparative control system using both a disturbance observer and a low-pass filter 1 is a block diagram of a first embodiment according to the present invention. Similarly block diagram The figure which shows the step response of the prior art example of FIG. The figure which shows the step response of the comparative example of FIG. The figure which shows the step response of 1st Embodiment of this invention. Block diagram when using speed feedforward in the second embodiment of the present invention Block diagram when the disturbance observer gain is automatically set to the cutoff frequency in the third embodiment of the present invention Block diagram showing phase lead compensation using a disturbance observer in the fourth embodiment of the present invention

Explanation of symbols

M ... Motor A ... Load 10 ... Disturbance observer 12, 14 ... Low-pass filter (LPF)

Claims (2)

In the vibration suppression control device of the positioning control device including the acceleration control system using the disturbance observer,
A low-pass filter is inserted in the position command portion, and the frequency of the disturbance observer gain value Gdis set for the positioning control device is set as a cutoff frequency of the low-pass filter in the position command portion. Vibration suppression control device for positioning control device.   In addition to the position command part, a low-pass filter is also inserted in the speed feedforward command part, and the frequency of the disturbance observer gain value Gdis set for the positioning control device is set to the speed feedforward command part. The vibration suppression control device for a positioning control device according to claim 1, wherein the vibration suppression control device is a cutoff frequency of a low-pass filter.

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