JPH09291902A - Servo controller for hydraulic actuator - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a servo control device capable of eliminating a response delay as much as possible. [Structure] A control signal output means 5 for generating a valve drive signal c based on a deviation between a target value signal a and a feedback signal b.
Is provided with correction means 6 for receiving and calculating the target value signal a and the feedback signal b to correct the valve drive signal d. The correction means 6 relates to the response delay of the feedback back signal b with respect to the target value signal a. The storage unit 6a that stores the response delay related data in association with the time differential value of the target value signal a so as to be updatable and outputs the response delay related data that is stored in association with the actual time differential value of the target value signal a. And the response delay related data output from the storage unit 6a, and corrects the valve drive signal d input to the control valve 2 to a value required to reduce the response delay of the feedback signal b with respect to the target value signal a. It is configured with a correction unit 6b that operates.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a servo control device for hydraulic actuators.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional servo control device for a hydraulic actuator. In FIG. 3, a servo control device for controlling the control valve 2 of the hydraulic actuator 1 relates to a target value signal generating means 3 for generating a target value signal a for instructing the driving of the hydraulic actuator 1, and an actual driving state of the hydraulic actuator. A drive state detecting means 4 for outputting a feedback signal, a target value signal a from the target value signal generating means 3 and a feedback signal b from the drive state detecting means 4 are received, and a deviation signal c between these signals a and b. And a control signal output means 5 for generating a valve drive signal d according to the deviation signal c and outputting the valve drive signal d to the control valve 2. In the figure, 5a is a valve drive signal calculation unit included in the control signal output means 5, and calculates the valve drive signal d according to the deviation signal c.

In the hydraulic actuator servo controller thus constructed, the control valve 2 of the hydraulic actuator 1 is switched so that the valve drive signal d from the control signal output means 5 follows the target value signal a with the feedback signal b. Since it is operated, the hydraulic actuator 1 can be arbitrarily driven by the target value signal a.

Such a hydraulic actuator servo control device is widely used for speed control for controlling the drive speed of the hydraulic actuator 1 or for position control for controlling the drive position of the hydraulic actuator 1. For speed control, the target value signal a is a target drive speed signal indicating the drive speed of the hydraulic actuator 1, and the feedback signal b is an actual drive speed signal indicating the actual drive speed of the hydraulic actuator 1. For position control,
The target value signal a is a target position signal indicating the drive position of the hydraulic actuator 1, and the feedback signal b is an actual drive position signal indicating the actual drive position of the hydraulic actuator 1.

[0005]

The above-mentioned conventional servo control system for hydraulic actuators is a hydraulic actuator which is detected via a target value (target speed or target position) indicated by a target value signal a and a feedback signal b. The hydraulic actuator 1 is driven on the premise of the deviation occurring between the actual driving states (speed or position) of No. 1 above. Therefore, when the target value signal a changes, there is a time delay (response delay) until the driving state (speed or position) of the hydraulic actuator 1 reaches the state (speed or position) instructed by this target value. . Such a response delay is caused by the drive resistance (friction resistance, inertia resistance) of the hydraulic actuator 1 and the switching resistance (friction resistance, inertia resistance) of the control valve.
Inevitably, the servo control system has such a delay, and the response delay varies depending on machine differences (individual differences in the same model) and aging. For this reason, the conventional hydraulic actuator servo control device has a problem that it is difficult to immediately respond to the target value signal a that changes the driving state (speed or position) of the hydraulic actuator 1.

An object of the present invention is to solve the problems of the conventional servo control device by adding a part of the configuration to the conventional servo control device, and to drive the hydraulic actuator 1 (speed or position). Is the fluctuating target value signal a
An object of the present invention is to provide a servo control device for a hydraulic actuator that can quickly respond to (speed or position).

[0007]

In order to achieve the above object, a servo control device for a hydraulic actuator of the present invention is configured as follows. A servo control device for controlling a control valve 2 of a hydraulic actuator 1, comprising a target value signal generating means 3 for generating a target value signal a for instructing driving of the hydraulic actuator 1, and a feedback signal relating to an actual driving state of the hydraulic actuator. The driving state detecting means 4 for outputting b, the target value signal a from the target value signal generating means 3 and the feedback signal b from the driving state detecting means 4 are received, and a deviation signal c between these signals a and b is received. A control signal output means 5 for calculating and generating a valve drive signal d according to the deviation signal c and outputting the valve drive signal d to the control valve 2, wherein the control signal output means 5 includes: The correction means 6 is provided for receiving the target value signal a and the feedback signal b, calculating the value, and correcting the valve drive signal d. The response delay related data relating to the response delay of the feedback signal b with respect to the signal a is stored updatable in association with the time differential value of the target value signal a, and also related to the time differential value of the actual target value signal a. The storage unit 6a that outputs the response delay related data and the response delay related data that is received from the storage unit 6a and is input to the control valve 2 is the response delay of the feedback signal b with respect to the target value signal a. Correction unit 6b that corrects to a value necessary to reduce
A servo control device for a hydraulic actuator, which is configured as described above.

[0008]

In the servo controller for hydraulic actuator of the present invention constructed as above, when the response of the driving state (speed or position) of the hydraulic actuator 1 is delayed with respect to the changing target value signal a (speed or position). First, response delay related data relating to this response delay is stored in the storage unit 6a in the correction unit 6 added in the control signal output unit 5. This response delay related data is calculated based on the target value signal a and the feedback signal b input to the storage unit 6a, and can be updated in association with the time differential value (changing speed) of the changing target value signal a. Data that is stored in the memory and is related to the deviation between the target value signal a and the feedback signal b.

The above-mentioned storage in the storage unit 6a is performed by the target value signal a.
The response delay data is updated and stored in association with the time differential value (variation speed) of. In this way, the response delay data stored in the storage unit 6a (response delay related data relating to the response delay of the feedback signal b with respect to the target value signal a, and stored updatable in association with the time differential value of the target value signal a) Corresponding response delay related data is read out by the read signal stored in relation to the time differential value (variation speed) of the actual target value signal a.

The response delay related data (corresponding to the actual time differential value of the fluctuating target value signal a) read from the storage section 6a is input to the correction section 6b. Correction unit 6b
Is to correct the valve drive signal d input to the control valve 2 to a value required to reduce the response delay of the feedback signal b with respect to the target value signal a, based on the input response delay-related data.

As a result, the response delay of the feedback signal b with respect to the fluctuating target value signal a (in other words, the actual driving of the hydraulic actuator 1 with respect to the speed or position of the hydraulic actuator 1 according to the instruction of the fluctuating target value signal a) The speed or drive position response delay) is greatly reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a servo control device for a hydraulic actuator according to the present invention will be described below with reference to FIGS.
As described above, since the servo control device of the present invention is obtained by adding a part of the configuration to the conventional servo control device, the reference numerals used in the above-mentioned conventional servo control device for hydraulic actuators have the same meaning. Use as it is.

In FIG. 1, 6 is a control signal output means 5.
It is a correction means provided inside. The correction unit 6 includes a storage unit 6a and a correction unit 6b. The storage unit 6
The target value signal a and the feedback signal b are input to a. The correction means 6 stores the response delay related data relating to the response delay of the feedback signal b with respect to the target value signal a so as to be updatable in association with the time differential value of the target value signal a, and also the actual target value signal. Response delay related data required for storage is output in association with the time differential value of a.

In the conventional servo control device, when the target value signal a changes as described above, the feedback signal b always follows the target value signal a with a delay. That is, there is a response delay. The storage unit 6a stores the data related to the response delay as the response delay related data in the target value signal a.
It is stored updatable in association with the time differential value (variation speed) of. The data related to the deviation between the target value signal a and the feedback signal b is used as the response delay related data that is stored in association with the time differential value (variation speed) of the target value signal a. The above storage in the storage unit 6a is
The response delay data corresponding to the time differential value (variation speed) of the target value signal a is updated and stored. In this case, the target value signal a
Of course, the response-delay-related data corresponding to the time differential value (fluctuation speed) of the fluctuating target value signal a is updated and stored, but in the case where the target value signal a does not fluctuate. Also, the response delay related data corresponding to the time differential value (variation speed = 0) of the target value signal a is updated and stored.

FIG. 2 shows an example of response delay data stored in association with the time differential value of the target value signal a. In FIG. 2, fluctuation velocities V1 to V5 (V1 <V5) of the target value signal a are adopted as the time differential value of the target value signal a, and the response delay related data S1 are associated with the fluctuation velocities V1 to V5, respectively. Up to S5 are stored so that they can be updated. The response delay-related data that can be updated is data related to the deviation between the target value signal a and the feedback signal b, and the deviation or the time differential value of the deviation is used. In short, the response delay related data may be any correction data required to correct the conventional valve drive signal d calculated according to only the deviation signal c to a value necessary to reduce the deviation signal c. Is.

The function of the storage unit 6a will be further described with reference to FIG. When the storage unit 6a receives the fluctuating target value signal a, it calculates the time differential value (variable speed in FIG. 2) of the receiving target value signal a, and which of the calculated values corresponds to V1 to V5. To calculate. Further, the storage unit 6a reads the corresponding response delay related data from the stored response delay related data S1 to S5 using the calculated V1 to V5 as index signals.

At the same time, the storage section 6a calculates the correction value δS of the response delay related data from the target value signal a and the feedback signal b relating to the reception. The correction value δS of the response delay related data is the deviation between the target value signal a and the feedback signal b or the valve drive signal d correction data necessary for reducing the deviation. Then, the correction value δS of the response delay related data relating to the calculation is added to the response delay related data read out above to obtain new response delay related data (a value obtained by adding δS to one of S1 to S5). Is calculated, and the calculation result is updated and stored (replaced and stored) in the read destination of the response delay related data read in and output to the correction unit 6b. That is, the update storage of the response delay related data S1 to S5 adds the actually generated response delay related data (correction value δS of the response delay related data) to the response delay related data related to the storage before the update, This is done by storing as new response delay related data S1 to S5.

The above-mentioned operations and update storage of the storage unit 6a can be easily realized by using known techniques, and therefore detailed description thereof will be omitted here.

The correction section 6b in the correction means 6 has the response delay related data S1 to S5 output from the storage section 6a.
The valve drive signal d is corrected based on Correction unit 6
The valve drive signal d is corrected by b so that the valve drive signal d is actually input to the control valve 2 so that the response delay of the hydraulic actuator 1 to the fluctuating target value signal a is reduced. Correct it. This correction is performed so that the valve drive signal d output from the control signal output means 5 to the control valve 2 becomes a value that reduces the response delay of the hydraulic actuator 1 with respect to the fluctuating target value signal a. In the embodiment shown in FIG. 1, an example in which such a correction is performed via the deviation signal c is shown, but a correction unit 6b is arranged after the valve drive signal calculation unit 5a to correct the valve drive signal d itself. You may do it. Further, this correction is performed by the response delay related data S1 to S related to the input from the storage unit 6a.
The deviation signal c with a value calculated as a function of 5 as a coefficient
(Or valve drive signal d) may be used, or response delay related data S related to the input from the storage unit 6a.
The deviation signal c (or the valve drive signal d) may be added as a value calculated as a function of 1 to S5.

The valve drive signal d thus corrected by the correction unit 6b is input to the control valve 2 to reduce the response delay of the hydraulic actuator 1 when the target value signal a changes. In the storage unit 6a of the correction unit 6,
Every time a response delay of the hydraulic actuator 1 occurs with respect to the fluctuating target value signal a, new response delay related data is stored in association with the time derivative of the target value signal a, and next time the target value signal a fluctuates. In addition, the corresponding response delay related data is read using the time differential value of the target value signal a relating to the fluctuation as an index signal, and the valve drive signal d is corrected based on the read response delay related data. Therefore, the response delay related data relating to the memory is gradually rewritten to the optimum value.

In the above embodiment, the target value signal a is a signal indicating the driving speed of the hydraulic actuator 1, the feedback signal b is a signal indicating the actual driving speed of the hydraulic actuator 1, and the target value is The case where the signal a is a signal indicating the driving position of the hydraulic actuator 1 and the feedback signal b is a signal indicating the actual driving position of the hydraulic actuator 1 is described as including both. Claim 1 includes both of them, claim 2 includes the former, and claim 3 includes the latter.

Further, in the above embodiment, the response delay related data stored updatable in the storage unit 6a is stored updatable in association with the time differential value of the target value signal a, and the actual target value signal a is stored. Although the time differential value is read out as an index signal, this response delay related data can be updated in association with the time differential value of the target value signal a for each changing value (level) of the target value signal a. Both the value (level) of the actual target value signal a and its time differential value may be read out as index signals while being stored. In this way, the valve drive signal d can be corrected using different response delay-related data for each value (level) of the target value signal a, so that the response delay changes the value of the target value signal a ( Even if it differs for each level), it is possible to accurately reduce it by the response delay.

The response-delay-related data stored in the storage unit 6a in association with the time differential value of the target value signal a so as to be updatable is only the first-order differential value of the target value signal a (in this case, the variable speed). The target value signal a may be stored in an updatable manner in association with the first differential value, the second differential value, ...
You may make it memorize | store as a total value of the data memorize | stored in association with each n-order differential value so that update was possible. It goes without saying that any case is included in the scope of the present invention.

Further, the following limitation may be added to the update storage of the response delay related data in the storage unit 6a in the correction means 6. When the difference between the response delay related data before updating stored in the storage unit 6a and the response delay related data to be updated exceeds a predetermined value set in advance, the response delay related data is limited to the predetermined value. The data is updated and stored. That is, when the response delay related data before update is set to the initial value,
The response delay-related data after updating is regulated so as not to be updated beyond a predetermined value set in advance with respect to this initial value. The predetermined value is stored in the storage unit 6a. In this case, for example, when the feedback signal b is abruptly separated from the actual driving state of the hydraulic actuator 1 due to noise or the like, or when the hydraulic actuator 1 is at the driving end (stroke end of the hydraulic cylinder, etc.). ) Etc.
It is possible to regulate the update storage of unnecessarily large response delay related data. This configuration corresponds to claim 4.

The update storable range (upper limit value and lower limit value) of the response delay related data is set, and the total value of the response delay related data that is sequentially updated and stored is the update storable range (upper limit value) related to this setting. And the lower limit). The update storable range (upper limit value and lower limit value) is stored in the storage unit 6a. In this case, even if the feedback signal b does not follow the target value signal a at all due to the failure of the servo control device, the data update related to the abnormal response delay is performed. It has the effects of limited memory and safety. This configuration corresponds to claim 5.

[0026]

The servo control device for hydraulic actuator according to the present invention constructed and operated as described above has a simple structure in which the correction means 6 is added to the conventional servo control device, but has the conventional servo control device. Fluctuating target value signal a
Since the response delay of the feedback signal b with respect to (the response delay of the hydraulic actuator 1) can be largely eliminated, the effect is extremely large.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining a servo control device for a hydraulic actuator according to the present invention.

FIG. 2 is an explanatory diagram of response delay related data stored updatable in a storage unit 6a of a correction unit 6;

FIG. 3 is a block diagram for explaining a conventional servo control device for a hydraulic actuator.

[Explanation of symbols]

1; hydraulic actuator, 2; control valve, 3; target value signal generation means, 4; drive state detection means, 5; control signal output means, 5a; valve drive signal calculation section, 6; correction means, 6a, storage section, 6b: correction unit, a: target value signal, b: feedback signal, c: deviation signal, d: valve drive signal,

Claims (5)

[Claims] 1. A servo control device for controlling a control valve 2 of a hydraulic actuator 1, comprising target value signal generating means 3 for generating a target value signal a for instructing the driving of the hydraulic actuator 1, and actual driving of the hydraulic actuator. The driving state detecting means 4 for outputting a feedback signal relating to the state, and the target value signal a from the target value signal generating means 3 and the feedback signal b from the driving state detecting means 4 are received. A control signal output means 5 for calculating a deviation signal c, generating a valve driving signal d in accordance with the deviation signal c, and outputting the valve driving signal d to the control valve 2, The means 5 is provided with a correcting means 6 for receiving and calculating the target value signal a and the feedback signal b to correct the valve drive signal d, and the correcting means Stores update-related response delay related data regarding the response delay of the feedback signal b with respect to the target value signal a in association with the time derivative of the target value signal a so as to be updatable and also relates to the time derivative of the actual target value signal a. Storage unit 6a for outputting response delay related data related to storage
And the response delay related data output from the storage unit 6a, and corrects the valve drive signal d input to the control valve 2 to a value required to reduce the response delay of the feedback signal b with respect to the target value signal a. A servo control device for a hydraulic actuator, which is configured with a correction unit 6b that operates. 2. A target value signal a for instructing the drive of the hydraulic actuator 1 is a target drive speed signal for instructing the drive speed of the hydraulic actuator 1, and a feedback signal b.
2. The servo control device for hydraulic actuator according to claim 1, wherein is an actual drive speed signal indicating an actual drive speed of the hydraulic actuator 1. 3. A target value signal a for instructing the drive of the hydraulic actuator 1 is a target drive position signal for instructing the drive position of the hydraulic actuator 1, and a feedback signal b.
The hydraulic actuator servo control device according to claim 1, wherein is an actual drive position signal indicating an actual drive position of the hydraulic actuator 1. 4. The storage unit 6a of the correction means 6 has a difference between a response delay related data before update stored in the storage unit 6a and a response delay related data to be updated, which exceeds a preset predetermined value. 4. The servo control device for a hydraulic actuator according to claim 1, wherein the servo control device is configured not to be updated and stored. 5. The storage section 6a of the correction means 6 is set with an update storable range of response delay related data,
5. The hydraulic actuator servo control device according to claim 1, wherein the total value of the response delay related data that is sequentially updated and stored does not exceed the update storable range related to this setting.