JP7032636B2 - Wasted time compensation device and resonance suppression control device equipped with it - Google Patents

Description

The present invention relates to a wasted time compensating device that compensates for the wasted time for a controlled object having wasted time.

It is known that when the control target is controlled, the command actually input to the control target is delayed with respect to the input command due to the sampling cycle, communication in the control device, and the like. Such delays are commonly referred to as wasted time. It is known that this wasted time affects the control of the controlled object.

For example, in the case of a multi-inertial resonance system in which the controlled object has a plurality of inertias and causes resonance, it is known that if the multi-inertial resonance system has wasted time, the vibration of the controlled object is affected. ..

In order to reduce the influence of vibration due to such wasted time, for example, the resonance suppression control device disclosed in Patent Document 1 is known. This resonance suppression control device suppresses the resonance frequency component by passing the shaft torsion torque detection value through a high-pass filter in consideration of the wasted time element due to the detection delay of the shaft torsion torque and the wasted time element of the torque transmission characteristic of the inverter. do.

Specifically, the resonance suppression control device subtracts the output of the bypass filter from the torque command, passes the subtracted output through the phase compensator to obtain the torque command value after phase compensation, and obtains the torque command value after phase compensation. Is given to the inverter as a motor torque command. The transfer function _GPHC of the phase compensator is as follows.
G _PHC = (α ・ s + ω _phc ) / (s + ω _phc )

However, α is a phase compensation parameter, and ω _phc is a phase compensation filter cutoff frequency.

Japanese Unexamined Patent Publication No. 2017-99084

The resonance suppression control device disclosed in Patent Document 1 described above can suppress the resonance frequency component of the shaft torsional torque detection value without affecting the DC component by using the high-pass filter. However, in the resonance suppression control device of Patent Document 1, in order to reduce the influence of wasted time in the motor torque command, the phase compensation parameter α is appropriately adjusted in consideration of the wasted time in the transfer function _GPHC of the phase compensator. There is a need to.

An object of the present invention is to provide a wasted time compensating device capable of easily compensating for the wasted time for a controlled object having wasted time.

The wasted time compensating device according to the embodiment of the present invention is a wasted time compensation device that compensates for the wasted time in a control system including a feedback loop in which an output value of a controlled object having wasted time is negatively fed back to an input command. It is a device. In this wasted time compensating device, in order to reduce the vibration of the controlled object, the estimated correction value calculation unit that calculates the vibration damping correction value from the estimated response value of the controlled object, and the waste time before the elapsed time elapses. The waste time calculation unit for calculating the vibration damping correction value, the vibration damping correction value calculated by the estimated correction value calculation unit, and the waste time calculated by the waste time calculation unit are not elapsed. A subtractor for calculating the difference from the vibration damping correction value is provided, and the output of the subtractor is negatively fed back to the input command to be controlled (first configuration).

As a result, the control target can be controlled without being affected by the wasted time. That is, the vibration damping correction value is calculated using the estimated response value of the control target obtained from the input command of the control target, and the vibration damping correction value and the vibration damping correction value when the wasted time is taken into consideration. By negatively feeding back the difference between the above to the input command of the control target, the control target can be controlled in consideration of the wasted time. Therefore, the resonance of the controlled object can be easily and effectively suppressed.

In the first configuration, the estimated correction value calculation unit obtains the vibration damping correction value by differentiating the estimated response value and multiplying it by a predetermined constant (second configuration).

Thereby, the above-mentioned first configuration can be realized. Specifically, in the block diagram shown in FIG. 2, the transfer function is represented by the equation (1).

Here, r is an input value, y is a response value, _P is a transfer function to be controlled, KD is a differential coefficient (predetermined constant), s is a differential operator, and L is a differential operator. It's a waste of time.

The transfer function to be controlled is expressed by Eq. (2).

Here, ω _n is the natural frequency, ζ is the damping ratio, and K is the gain to be controlled.

By substituting the above equation (1) with the equation (2), a transfer function as shown in the following equation (3) can be obtained.

The above equation (3) is expressed using a transfer function that suppresses resonance and a transfer function e ^-Ls of wasted time. Therefore, it is possible to suppress the resonance of the controlled object while considering the wasted time. Therefore, the resonance of the controlled object can be suppressed more effectively.

The resonance suppression control device according to an embodiment of the present invention is a resonance suppression control device that suppresses resonance of a multi-inertial resonance system including a feedback loop that negatively feeds back an output value of a controlled object having wasted time to an input command. Is. This resonance suppression control device includes the wasted time compensating device according to the first or second configuration, and a damping ratio adjusting unit provided in the feedback loop to adjust the vibration damping ratio (third configuration). ).

As a result, the resonance of the multi-inertia resonance system provided with the feedback loop for the controlled object in which the resonance occurs can be effectively suppressed in consideration of the wasted time.

In the third configuration, the resonance suppression control device further includes a disturbance suppression unit that suppresses the disturbance input to the input command to be controlled (fourth configuration). As a result, even when a disturbance is input to the input command of the control target, the influence of the disturbance can be eliminated and the control target can be controlled while considering the wasted time.

In the third or fourth configuration, the resonance suppression control device further includes a filter that extracts a predetermined vibration mode from the plurality of vibration modes to be controlled (fifth configuration). As a result, even when the controlled object has a plurality of vibration modes, resonance can be suppressed in consideration of wasted time for each vibration mode.

The waste time compensating device according to the embodiment of the present invention has an estimated correction value calculation unit that calculates a vibration damping correction value from an estimated response value of a controlled object, and the vibration damping correction value before the waste time elapses. The calculated waste time calculation unit, the vibration damping correction value calculated by the estimated correction value calculation unit, and the vibration damping correction value calculated by the waste time calculation unit before the waste time elapses. A subtractor for calculating the difference is provided, and the output of the subtractor is negatively fed back to the input command to be controlled. As a result, the control target can be controlled without being affected by the wasted time. Therefore, it is possible to obtain a wasted time compensating device that can easily compensate for the wasted time in the control of the controlled object.

FIG. 1 is a functional block diagram showing a schematic configuration of a test device provided with a waste time compensation device according to the first embodiment. FIG. 2 is a block diagram of the control device according to the first embodiment. FIG. 3 is a Bode diagram to be controlled. FIG. 4 is a diagram showing a step response to be controlled. FIG. 5 is a diagram corresponding to FIG. 2 of the control device according to the second embodiment. FIG. 6 is a diagram corresponding to FIG. 2 of the control device according to the third embodiment. FIG. 7 is a diagram corresponding to FIG. 2 of the control device according to the fourth embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the figure are designated by the same reference numerals and the description thereof will not be repeated.

<Embodiment 1>
(overall structure)
FIG. 1 is a diagram showing a schematic configuration of a test device 1 provided with a waste time compensation device according to the first embodiment of the present invention in functional blocks. This test device 1 is a test device for testing the characteristics of a specimen M such as an automobile motor. The specimen M to be tested by the test apparatus 1 may be a rotating body other than the motor.

Specifically, the test device 1 includes a control device 2, a motor drive circuit 3, an electric motor 4, and a torque detector 5.

The control device 2 generates a drive command for the motor drive circuit 3 by using the motor torque command r which is an input command and the feedback value described later. The control device 2 has a feedback loop 10 (resonance suppression control device) that negatively feeds back to the motor torque command r using the output value of the torque detector 5 (see FIG. 2). Since the configuration in which the control device 2 generates the drive command is the same as in the conventional case, detailed description of the control device 2 will be omitted. The configuration of the feedback loop 10 will be described later.

Although not particularly shown, the motor drive circuit 3 has a plurality of switching elements. The motor drive circuit 3 supplies electric power to a coil (not shown) of the electric motor 4 by driving the plurality of switching elements based on the drive command.

The electric motor 4 has a rotor and a stator (not shown). By supplying electric power from the motor drive circuit 3 to the coil of the stator, the rotor rotates with respect to the stator. The rotor is rotatably connected to the specimen M with respect to the specimen M via an intermediate shaft (not shown). As a result, torque can be output from the electric motor 4 to the specimen M by the rotation of the rotor. Since the configuration of the electric motor 4 is the same as the configuration of a general motor, detailed description of the electric motor 4 will be omitted.

The torque detector 5 is provided on an intermediate shaft connecting the electric motor 4 and the specimen M. The torque detector 5 detects the torque output from the electric motor 4. The output value of the torque detected by the torque detector 5 is input to the control device 2 as an input value of the feedback loop 10. That is, the output value of the torque detector 5 is used for feedback control. Since the configuration of the torque detector 5 is the same as the conventional configuration, detailed description of the torque detector 5 will be omitted.

In the test device 1 having the above-described configuration, mechanical resonance (simply referred to as resonance) occurs when the electric motor 4 rotates due to the rigidity of the shaft system including the electric motor 4, the torque detector 5, and the specimen M. In the test of the test piece M, when the resonance occurs within the frequency measurement range, the torque detector 5 detects the torque (for example, shaft torque) obtained by adding the vibration component of the resonance to the output torque of the electric motor 4. To torque. Therefore, it is desired to remove the vibration component of the resonance.

On the other hand, in the present embodiment, as shown in FIG. 2, the control device 2 has a feedback loop 10 that feeds back the output value of the torque detector 5 to the motor torque command r which is an input command, and the control target P. It has a wasted time compensating unit 20 (wasted time compensating device) for considering the wasted time when controlling. That is, the test device 1 of the present embodiment controls the drive of the electric motor 4 by a control system including the control device 2, the motor drive circuit 3, the electric motor 4, and the torque detector 5 and not including the specimen M.

In FIG. 2, r is a target value (input value) as a motor torque command, y is an output value (response value) of the torque detector 5, _KD is a differential coefficient, and s is a differential element. And L is wasted time.

Further, the reference numeral P in FIG. 2 is a control target, and in the present embodiment, the control target P includes a motor drive circuit 3, an electric motor 4, and a torque detector 5. The controlled object P also includes a range from the electric motor 4 to the torque detector 5 in the intermediate shaft connecting the electric motor 4 and the specimen M.

Further, in FIG. 2, P ^ is an estimated value of the response value (output value of the torque detector) of the controlled object P, and e ^-Ls ^ is a value considering the wasted time in the estimated response value of the controlled object P. Is. In the following, "^" attached above each character in each figure will be described after each character for convenience of explanation.

The feedback loop 10 is a differential feedback system including the differential element s. The output value of the torque detector 5 is input to the feedback loop 10. The feedback loop 10 has a damping ratio adjusting unit 51. The damping ratio adjusting unit 51 adjusts the damping ratio with respect to the controlled object by the differential element s and the differential coefficient _KD . In the feedback loop 10, the output value of the torque detector 5 is processed by the damping ratio adjusting unit 51 and then negatively fed back to the motor torque command r as a feedback value.

The wasted time compensation unit 20 corrects the input command of the controlled object P so as to eliminate the influence of the wasted time. Specifically, the wasted time compensating unit 20 obtains the vibration damping correction value from the estimated response value of the controlled object P, and is the difference between the vibration damping correction value and the vibration damping correction value due to the estimated wasted time. Is negatively fed back to the input command of the controlled object P. As a result, the wasted time compensation unit 20 can eliminate the influence of the wasted time from the input command.

Specifically, the waste time compensation unit 20 has an estimated correction value calculation unit 61, a waste time calculation unit 62, and a subtractor 63. The estimation correction value calculation unit 61 obtains the vibration damping correction value by differentiating the response value P ^ estimated from the input command of the control target _P and multiplying it by the differential coefficient KD. The waste time calculation unit 62 obtains the vibration damping correction value before the estimated waste time. The subtractor 63 obtains the difference between the vibration damping correction value obtained by the estimation correction value calculation unit 61 and the vibration damping correction value before the wasted time. Therefore, the value output from the subtractor 63 is a vibration damping correction value excluding the influence of wasted time. The output of the subtractor 63 is negatively fed back to the input command of the controlled object P.

As described above, by correcting the input command of the control target P by using the vibration damping correction value from which the influence of the waste time is eliminated, the influence of the waste time can be eliminated in the control of the control target P. Therefore, the resonance of the controlled object P can be suppressed without being affected by the wasted time.

Here, when the configuration in the block diagram shown in FIG. 2 is shown by a transfer function, the transfer function is the following equation (1).

The transfer function of the controlled object P is the following equation (2).

In the above equation (2), ω _n is the natural frequency, ζ is the damping ratio, and K is the gain to be controlled.

By substituting the above equation (1) with the equation (2), the following equation (3) can be obtained.

As shown in the above equation (3), the transfer function in the block diagram of FIG. 2 is expressed by using the transfer function that suppresses the resonance of the controlled object P and the transfer function e ^-Ls of wasted time. As described above, the configuration of the block diagram shown in FIG. 2 makes it possible to suppress the resonance of the controlled object P while considering the wasted time.

FIG. 3 shows a Bode diagram showing the effect of the present embodiment. In FIG. 3, the upper figure is a Bode diagram showing the gain characteristics, and the lower figure is a Bode diagram showing the phase characteristics. In the Bode diagram of FIG. 3, the waveform when the wasted time is taken into consideration (“the present embodiment” in FIG. 3) is shown by a solid line, and the differential feedback control is performed without considering the wasted time (“in FIG. 3”. The waveform with the differential FB is shown by a broken line, and the waveform without the differential feedback control (without the differential FB in FIG. 3) is shown by the alternate long and short dash line.

As shown in FIG. 3, when the wasted time is taken into consideration as in the present embodiment, resonance is caused as compared with the case where the differential feedback control is not performed and the case where the differential feedback control is performed without considering the wasted time. It can be suppressed. Therefore, it can be seen that resonance can be effectively suppressed by considering the wasted time as in the present embodiment.

FIG. 4 shows a step response showing the effect of the present embodiment. Note that FIG. 4 shows the output of the controlled object when a step signal having a signal strength of 1 is input (two-dot chain line), that is, the time change of the signal strength output from the torque detector 5. In FIG. 4, the waveform when the wasted time is taken into consideration (“the present embodiment” in FIG. 3) is shown by a solid line, and the differential feedback control is performed without considering the wasted time (“with differential FB” in FIG. 3”. ) Is shown by a broken line. In FIG. 4, the waveform of the input step signal is shown by a two-dot chain line.

As shown in FIG. 4, when the wasted time is taken into consideration as in the present embodiment, unlike the case where the differential feedback control is performed without considering the wasted time, the fluctuation of the signal strength at the time of signal rise is almost the same. do not have. Therefore, it can be seen that the configuration of the present embodiment can control the controlled object P with good responsiveness while suppressing vibration.

As described above, by the configuration of the present embodiment in which the input command of the control target P is corrected in consideration of the wasted time, the control target P can be controlled with good responsiveness while easily suppressing the resonance of the control target P. can.

<Embodiment 2>
FIG. 5 shows a block diagram of the control device 102 according to the second embodiment. The configuration shown in FIG. 5 is different from the configuration of the first embodiment in that the waste time compensation unit 20 is provided outside the feedback loop 110. In the following, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted, and only the parts different from the first embodiment will be described.

As shown in FIG. 5, the waste time compensation unit 20 is provided outside the feedback loop 110 of the control device 102. In this embodiment, the feedback loop 110 is configured so as to have the same transfer function as the block diagram shown in FIG. 2 of the first embodiment. That is, the feedback loop 110 has the same attenuation ratio adjusting unit 51 as in the first embodiment and the feedback loop waste time compensating unit 153.

The feedback loop waste time compensation unit 153 considers the waste time in the feedback loop 110. That is, the feedback loop waste time compensation unit 153 includes a response estimation unit 154 that estimates the response value of the control target P, and a waste time calculation unit 155 that obtains the waste time in the estimated response value of the control target P. It has a subtractor 156.

The response estimation unit 154 estimates the response value of the controlled target P using the output value of the attenuation ratio adjusting unit 51 of the feedback loop 110. The wasted time calculation unit 155 calculates the wasted time of the estimated response values of the controlled object P. The subtractor 156 obtains the difference between the response value estimated by the response estimation unit 154 and the wasted time of the response value calculated by the wasted time calculation unit 155. The output of the subtractor 156 is negatively fed back to the input side of the attenuation ratio adjusting unit 51 of the feedback loop 110. This allows the wasted time to be considered within the feedback loop 110.

With the above configuration, the transfer function of the block diagram shown in FIG. 5 is the same as the transfer function of the block diagram shown in FIG. 2, so that the same effects as those of the first embodiment can be obtained in the configuration of the second embodiment. ..

<Embodiment 3>
FIG. 6 shows a block diagram of the control device 202 according to the third embodiment. The configuration shown in FIG. 6 differs from the configuration of the first embodiment in that it has a disturbance observer 270. In the following, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted, and only the parts different from the first embodiment will be described.

As shown in FIG. 6, the disturbance observer 270 has a prediction unit 271, a subtractor 272, and a correction unit 273. The prediction unit 271 predicts the response value of the control target P including the wasted time from the input command of the control target P. The subtractor 272 obtains the difference between the response value predicted by the prediction unit 271 and the actual response value of the controlled object P. The correction unit 273 obtains an observer value by using the output of the subtractor 272 and the observer gain Kob. The obtained observer value is positively fed back to the input command of the controlled object P.

As a result, it is possible to control the controlled object P by eliminating not only the wasted time but also the influence of the disturbance d.

<Embodiment 4>
FIG. 7 shows a block diagram of the control device 302 according to the fourth embodiment. The configuration shown in FIG. 7 is different from the configuration of the first embodiment in that the feedback loop 310 has a filter 352 for extracting the vibration mode. In the following, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted, and only the parts different from the first embodiment will be described.

In the example of FIG. 7, a case where the controlled object P has a secondary vibration mode and the filter 352 extracts the primary vibration mode generated in the controlled object P is shown.

As shown in FIG. 7, the feedback loop 310 has an attenuation ratio adjusting unit 51 and a filter 352. The filter 352 extracts only a predetermined vibration mode from a plurality of vibration modes generated in the controlled object P. By considering the wasted time by the wasted time compensating unit 20 for the extracted vibration mode as in the first embodiment, the resonance of the controlled object P in the vibration mode can be suppressed.

The vibration mode of the controlled object P may be third or higher. Further, the vibration mode extracted by the filter 352 may be a vibration mode other than the primary vibration mode.

Further, although not particularly shown, by extracting a plurality of vibration modes of the controlled object P and considering the wasted time by the wasted time compensating unit 20 of the first embodiment for each vibration mode, in each of the vibration modes. Resonance can be suppressed.

(Other embodiments)
Although the embodiment of the present invention has been described above, the above-described embodiment is merely an example for carrying out the present invention. Therefore, the embodiment is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented within a range that does not deviate from the gist thereof.

In each of the above embodiments, the wasted time is considered by the wasted time compensating unit 20 in the differential feedback control. However, the waste time may be considered as in the above-described embodiment for the feedback control other than the differential feedback control and the control in which the waste time affects.

In each of the above embodiments, the controlled object P includes a motor drive circuit 3, an electric motor 4, and a torque detector 5. However, the controlled object may include other configurations or may include an axis system having other configurations.

In the third embodiment, the control device 202 has a disturbance observer 270, and in the fourth embodiment, the control device 302 has a filter 352 for extracting the resonance vibration mode of the controlled object P. The controller may have both a disturbance observer and a filter.

INDUSTRIAL APPLICABILITY The present invention can be used as a wasted time compensating device that compensates for the wasted time for a controlled object having wasted time.

1 Test device 2, 102, 202, 302 Control device 3 Motor drive circuit 4 Electric motor 5 Torque detector 10, 110, 310 Feedback loop 20 Waste time compensation unit (Waste time compensation device)
51 Damping ratio adjustment unit 61 Estimated correction value calculation unit 62 Wasted time calculation unit 63 Subtractor 153 Waste time compensation unit for feedback loop 154 Response estimation unit 155 Wasted time calculation unit 156 Subtractor 270 Disturbance observer 271 Predictor unit 272 Subtractor 273 Correction unit 352 Filter P Control target

Claims (4)

A wasted time compensating device that compensates for the wasted time in a control system provided with a feedback loop that negatively feeds back the output value of the controlled object having wasted time to an input command.
In order to reduce the vibration of the controlled object, an estimated correction value calculation unit that calculates a vibration damping correction value from the estimated response value of the controlled object, and
A waste time calculation unit that calculates the vibration damping correction value before the waste time elapses,
It is provided with a subtractor for calculating the difference between the vibration damping correction value calculated by the estimated correction value calculation unit and the vibration damping correction value calculated by the waste time calculation unit before the waste time elapses. ,
The output of the subtractor is negatively fed back to the input command to be controlled.
The estimated correction value calculation unit is a waste time compensation device that obtains the vibration damping correction value by differentiating the estimated response value and multiplying it by a predetermined constant . It is a resonance suppression control device that suppresses the resonance of a multi-inertial resonance system equipped with a feedback loop that negatively feeds back the output value of the controlled object with wasted time to the input command.
The wasted time compensating device according to claim 1 and
A damping ratio adjusting unit provided in the feedback loop to adjust the damping ratio of vibration,
A resonance suppression control device. In the resonance suppression control device according to claim 2 ,
A resonance suppression control device further comprising a disturbance suppression unit that suppresses a disturbance input to an input command to be controlled. In the resonance suppression control device according to claim 2 or 3 .
A resonance suppression control device further comprising a filter that extracts a predetermined vibration mode from a plurality of vibration modes to be controlled.

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