JPH06289905A - Adaptive control method and its device - Google Patents

Abstract

PURPOSE:To simplify a pre-processing when a system is made robust by obtaining a dead zone width based on the characteristic of a controlled system and executing an identification rule processing and a control rule processing only when control input is larger than the dead zone width. CONSTITUTION:A dead zone width holding part 7 obtains and holds a dead zone based on the characteristic of the controlled system 2. The parameter of the controlled system 2 is identified by supplying the respective output values of a controller 1 and the controlled system 2 through low pass filters 3 and 4. The output of the identifier 5 is supplied to the controller 1 as gain change indication data through a swtich 6. The output value of the controlled system 2 is fed back to the controller 1. When a control input value is within the range of the dead zone, a size discrimination part 8 discriminates it, controls the switch 6 to an OFF-state and sets it to a state where adaptive control is not executed. Thus, the pre-processing can be simplified, only control input beyond the range of the dead zone is adaptively controlled and the system can be made robust.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adaptive control method and apparatus therefor, and more specifically, it identifies a parameter based on a control input value and an output value from a controlled object,
The present invention relates to an adaptive control method and apparatus for changing the gain of a controller based on a parameter identification result.

[0002]

2. Description of the Related Art Conventionally, in order to control a controlled object having a dead zone represented by a hydraulic system with high accuracy, a parameter of the controlled object is identified based on a control input value and an output value from the controlled object. An adaptive control device has been proposed in which the gain of the controller is changed based on the parameter identification result. Further, in order to make such an adaptive control device robust (hardened against disturbance), the adaptive control device shown in FIG. 5 has been proposed.

In FIG. 5, a control target value is supplied to a controlled object 52 through a controller 51, and an output value from the controlled object 52 is fed back to the controller 51.
Therefore, the control input corresponding to the difference between the control target value and the output value is supplied to the controlled object 52. In addition, the control input value and the output value are set to the low pass filter 5
3 and 54 to the identifier 55 and the expression error discriminator 56, the identifier 55 performs the parameter identification processing of the controlled object 52, and the expression error discriminator 56 converts the parameters identified as the actual output value into the identified parameter. A determination process is performed as to whether or not the difference (hereinafter, referred to as an equation error) from the output value calculated on the basis of the output value is a predetermined threshold value or less. And
The switch 57 is controlled based on the discrimination result of the formula error discriminator 56, and the parameter identification result by the identifier 55 is supplied to the controller 51 only when the formula error is larger than a predetermined threshold, and the gain of the controller 51 is increased. Change.

Therefore, it is considered that the adaptive control is performed only when the expression error is large, and the adaptive control is not performed when the expression error is small, so that the controlled object having the dead zone can be controlled with high accuracy. reference). FIG. 6 shows a case where a hydraulic device is used as a control target and the threshold value of the equation error is set to 5 μm.

[0005]

However, in order to control a controlled object having a dead zone with high accuracy by the adaptive control device of FIG. 4, it is necessary to set a predetermined threshold value accurately.
In addition, since the threshold setting process is complicated, there is a disadvantage that it takes a considerably long time to perform the process setting of the adaptive control device so as to actually achieve the highly accurate control.

More specifically, since the magnitude of the expression error does not directly correlate with the width of the dead zone, the controlled object can be controlled with high accuracy while the threshold value of the expression error is set by trial and error. There was no choice but to check if it was possible. Therefore, it may happen that the optimum threshold value is set, but on the average, the threshold value is set and confirmation of whether or not the control target can be controlled with high accuracy is performed multiple times.
In some cases it may be necessary to iterate many times. Further, even if the optimum threshold value is once obtained, for example, in the case of a hydraulic system, the characteristics of the control target change due to load fluctuations, temperature fluctuations, etc. Must be performed,
The processing becomes more complicated.

If the threshold value is set too high, the adaptive control is not performed despite the range where the adaptive control should be performed, and the control accuracy of the controlled object is deteriorated (deviation becomes large). (See FIG. 7). On the contrary, if the threshold value is set too small, the adaptive control is performed even though the adaptive control should not be performed, and the control target becomes unstable (see FIG. 8). 7 and 8 show a case where a hydraulic device is used as a control target and the threshold values of the equation error are set to 10 μm and 1 μm, respectively.
Therefore, in order to sufficiently increase the control accuracy and obtain a threshold value that can stably control the controlled object, it is generally necessary to perform trial and error a large number of times.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an adaptive control method and apparatus capable of simplifying preprocessing for robustness by more directly detecting a dead zone. The purpose is to do.

[0009]

In order to achieve the above object, the adaptive control method according to claim 1 calculates a control input value on the basis of a control target value and an output value from a controlled object, and outputs the control input value. Is determined to be included in the dead zone, and the control target is adaptively controlled only when it is determined that the control input value is not included in the dead zone.

An adaptive control device according to a second aspect of the present invention is a control input value calculating means for calculating a control input value based on a control target value and an output value from a controlled object, and whether or not the control input value is included in the dead zone. It includes a determining means for determining and an adaptive control means for adaptively controlling the control target in response to the determination result of the determining means indicating that the control input value is not included in the dead zone.

[0011]

According to the adaptive control method of claim 1, in adaptively controlling a control object having a dead zone, a control input value is calculated based on a control target value and an output value from the control object, and the control input value is calculated. Is included in the dead zone, and the control target is adaptively controlled only when it is determined that the control input value is not included in the dead zone.Therefore, the dead zone width of the control target should be measured in advance. As a result, compared to the conventional method of setting the threshold value, preprocessing can be achieved significantly more easily, and based on the preprocessing result, adaptive control is performed only for control inputs outside the dead zone, making robustness possible. Can be achieved.

According to the dead zone adaptive control device of claim 2,
In adaptively controlling the control target having a dead zone, the control input value is calculated by the control input value calculation means based on the control target value and the output value from the control target, and the control input value is included in the dead zone by the determination means. Whether or not the control input value is included in the dead zone is determined, and the adaptive control means can adaptively control the controlled object in response to the determination result of the determination means. Therefore, by measuring the dead zone width of the controlled object in advance, preprocessing can be achieved significantly more easily than the conventional method of setting the threshold value, and based on the preprocessing result, the control input outside the range of the dead zone can be achieved. Robustness can be achieved by performing adaptive control corresponding to only.

[0013]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 1 is a flow chart for explaining an embodiment of the adaptive control method of the present invention. In step SP1, the dead zone width of the controlled object is measured, and in step SP2, wait until a control target value and an output value from the controlled object are received. In step SP3, the control input is calculated based on the control target value and the output value, and in step SP4, the magnitude of the control input and the dead zone width is discriminated. Then, if the control input is equal to or less than the dead zone width, the processing of step SP2 is performed again as it is. On the contrary, if the control input is larger than the dead zone width, adaptive law processing is performed in step SP5 to identify the parameter to be controlled, and step SP6.
At, the control law process based on the identified parameters is performed. After the processing of step SP6 is performed, the processing of step SP2 is performed again.

As is clear from the above description, the robustness of the adaptive law in the adaptive control can be achieved only by performing the preprocessing of step SP1, and this processing can be performed based on the characteristics of the controlled object. As in the conventional method, it is not necessary to carry out trial and error a large number of times, so that the pretreatment can be simplified and the required time can be greatly shortened.

FIG. 2 is a diagram showing the result of adaptive control according to this embodiment, and it can be seen that adaptive control can be performed with high accuracy and stability.

[0016]

[Embodiment 2] FIG. 3 is a block diagram showing an embodiment of the adaptive control apparatus of the present invention, in which a control target value is supplied to a controlled object 2 via a controller 1 and an output of the controlled object 2 is output. The value is fed back to the controller 1. Then, the output value of the controller 1 and the output value of the controlled object 2 are supplied to the identifier 5 via the low-pass filters 3 and 4, respectively, and the output of the identifier 5 is controlled as gain change instruction data via the switch 6. It is supplied to vessel 1. Further, the dead band width holding unit 7 that obtains and holds the dead band width based on the characteristics of the controlled object 2 and the size of the dead band width and the output value of the controller 1 are discriminated to output a signal for controlling the switch 6. And a discrimination unit 8.

The controller 1 obtains and outputs a control input value to be supplied to the controlled object 2 based on the difference between the control target value and the output value of the controlled object 2. The identifier 5 identifies the parameter of the controlled object 2 based on the control input value and the output value of the controlled object 2, and outputs the gain setting signal to the controller 1 based on the identification result. For example, when the characteristic of the controlled object 2 is as shown in FIG. 4, the dead band width holding unit 7 sets the dead band width to a range in which the output of the controlled object 2 is 0 (or almost 0) even if the control input changes. Is what you get.

The operation of the adaptive control device having the above configuration is as follows. When the control target 2 is adaptively controlled by supplying the control target value to the controller 1, the dead band width holding unit 7 obtains and holds the dead band width based on the characteristics of the control target 2. Then, the output value of the controller 1 and the output value of the controlled object 2 are supplied to the identifier 5 via the low-pass filters 3 and 4, respectively, to identify the parameter of the controlled object, and the output of the identifier 5 is switched to the switch 6. The data is supplied to the controller 1 as gain change instruction data via. Further, since the output value of the controlled object 2 is fed back to the controller 1, highly accurate adaptive control can be achieved corresponding to the control input value that does not belong to the dead zone. Further, when the control input value is included in the range of the dead band width, the size determining unit 8 determines that the dead band width is larger, so the switch 6 is controlled to the OFF state and the adaptive control is not performed. To do.

As is apparent from the above description, in this embodiment, the dead band width is directly obtained based on the characteristics of the controlled object 2 instead of setting the threshold value by trial and error, and therefore, in a short time. Can easily achieve robust adaptive control.

[0020]

As described above, according to the first aspect of the present invention, by pre-measuring the dead band width of the controlled object, the pre-processing can be achieved significantly more easily as compared with the conventional method of setting the threshold value. Based on the result of the preprocessing, there is a unique effect that the robustness can be achieved by performing the adaptive control only in response to the control input outside the dead zone.

According to the second aspect of the present invention, by measuring the dead zone width of the controlled object in advance, the preprocessing can be achieved significantly more easily than the conventional method of setting the threshold value. , The unique effect that the robustness can be achieved by performing the adaptive control only in response to the control input outside the range of the dead zone.

[Brief description of drawings]

FIG. 1 is a flowchart illustrating an embodiment of an adaptive control method of the present invention.

FIG. 2 is a diagram showing a transition of deviation when the hydraulic system is adaptively controlled by the method of FIG.

FIG. 3 is a block diagram showing an embodiment of the adaptive control device of the present invention.

FIG. 4 is a diagram showing an example of a flow gain static characteristic of a hydraulic device.

FIG. 5 is a block diagram showing a configuration of a conventional adaptive control device.

FIG. 6 is a diagram showing a transition of deviation when an appropriate threshold value is set.

FIG. 7 is a diagram showing a transition of deviation when the threshold value is too large.

FIG. 8 is a diagram showing a transition of deviation when the threshold value is too small.

[Explanation of symbols]

 1 Controller 2 Control Target 5 Identifier 6 Switch 7 Dead Band Width Holding Section 8 Large / Small Discrimination Section

Claims (2)

[Claims] 1. A method for adaptively controlling a controlled object (2) having a dead zone, the control target value and the controlled object (2).
The control input value is calculated based on the output value from, and it is determined whether the control input value is included in the dead zone. Only when it is determined that the control input value is not included in the dead zone, the control target (2) An adaptive control method characterized by adaptively controlling. 2. A device for adaptively controlling a controlled object (2) having a dead zone, the control target value and the controlled object (2).
Control input value calculating means (1) for calculating the control input value based on the output value from the control input value, determining means (7) (8) for determining whether the control input value is included in the dead zone, and the control input value Adaptive control means (5) (6) for adaptively controlling the controlled object (2) in response to the discrimination result of the discrimination means (8) indicating that is not included in the dead zone. .