JPH04123102A - Auto tuning device for control parameter - Google Patents

Abstract

PURPOSE:To shorten the time for adjusting a parameter and to execute the adjustment with high accuracy by providing a judging means for judging data of an estimation process, and executing a correction in accordance with its judgement. CONSTITUTION:A control characteristic analyzing means (first means) 11 calculates a characteristic value, and gives its calculation result to a parameter estimating means (second means) 12. Subsequently, an output of a second means 12 is inputted to a transition output means (fourth means) 14 of an adjustment parameter, a locus of a transition of a parameter of an adjustment process is derived by a fourth means 14, and based on its result, a judgement of an adjustment state is executed by adjustment state judging means (fifth means) 15. As a result of judgement in the adjustment state judging means (fifth means) 15, in the case it is judged that the adjustment is necessary, an adjustment parameter selecting means (six means) 16 executes selection so that the adjustment is executed from the adjustment parameter whose degree of importance is high to a control system. Also, as for other judgement result of the adjustment state judging means 15, the correction is executed by an adjustment correcting means (seventh means) 17. In such a way, the adjustment time is shortened and the accuracy can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an auto-tuning device for automatically adjusting parameters in components necessary for controlling a controlled object.

(Prior Art) Conventionally, in a control device having an automatic adjustment function, an automatic adjustment method based on trial and error has been used to adjust the parameters of the components necessary to control the controlled object. has been used. FIG. 3 shows an example of a tuning device that performs this trial-and-error adjustment.

In FIG. 3, the basic configuration of the control system is a control device 2 including a controller 3 that calculates the manipulated variable to zero the deviation between the target value of the controlled object and the controlled amount, and a control device 2 that is controlled by the control device 2. It consists of a controlled object 4. The controlled variable of the controlled object 4 is fed back to the control device 2 to be compared with a target value. control characteristic analysis means (first means) 11 for examining the characteristics of the control system including the controlled object 4 in order to adjust the parameters included in the controller 3;
Parameter estimation means (second means) I2 and adjustment parameter setting means (third means) 13 are provided. The first means 11 includes a test signal generation means 11a, a waveform recognition means 11b, and an adjustment completion determination means 11c. The test signal generation means 11a executes a test run including the controlled object 4, the waveform recognition means 11b obtains the characteristic value of the waveform representing the control characteristics, and the result is adjusted by the adjustment completion determination means lie. Unless it is determined that the process has ended, it is input to the parameter estimating means 12 and an estimated value is calculated.

The adjustment parameter setting means 13 uses the estimated value here.
New settings are made to the controller 3 via , and adjustments are made again. Adjustment completion determination means 1 for the above operations
Desired parameter adjustments are made repeatedly until it is determined that the adjustment has been completed based on step 1c.

(Problems to be Solved by the Invention) The conventional autotuning device described above has the following problems.

(1) At the final stage of parameter adjustment by the autotuning device, the estimation result oscillates around the optimal adjustment value and does not converge easily, so the adjustment takes time.

(2) In the case where there are multiple adjustment parameters and the values of the parameters are different, it is not possible to accurately judge which one to select when similar characteristic values are obtained.

(3) At the initial stage when the auto-tuning device adjusts parameters, even if the adjustment target is similar, the adjustment is performed again as a completely new control target, so it takes a long time each time for the adjustment.

The present invention has been made in consideration of the above circumstances, and it is an object of the present invention to provide an auto-tuning device for control parameters that can shorten adjustment time and improve accuracy.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a system for controlling a control system including a controlled object in order to adjust control parameters in components necessary for controlling the controlled object. a first means for examining the characteristics; a second means for estimating more appropriate parameter values of the control system according to a predetermined adjustment rule from the examined characteristics; and a third means for newly setting a control parameter of a control device,
a fourth means for storing the estimation process of the second means and outputting a parameter transition trajectory; a fifth means for determining the adjustment state from the parameter transition trajectory; and a fifth means for determining the adjustment state from the parameter transition trajectory. As a result, when it is determined that adjustment is necessary, a sixth means selects an adjustment parameter, a fourth means, and a fifth means.
and a seventh means for correcting the estimation result of the second means based on the respective outputs of the means and the sixth means.

Furthermore, the autotuning device of the present invention includes an eighth means for storing data indicating the adjustment result of the control parameters based on the output of the seventh means in combination with data indicating known operating conditions such as control specifications; a ninth means for searching for data similar to the current operating conditions from the data stored in the eighth means; and a tenth means for estimating adjustment parameters based on the similar data searched by the ninth means.
The invention is characterized in that it further includes means.

(Function) According to the above configuration, the convergence value of each parameter can be estimated well by the seventh means from the adjustment trajectory up to the previous time, thereby making it possible to quickly and accurately adjust the appropriate control parameters. .

Further, by using the above-mentioned adjustment data and data obtained before adjustment, the auto-tuning device can be provided with a learning function, and thereby control parameters can be adjusted more quickly and appropriately.

(Embodiment) FIG. 1 shows a first embodiment of an autotuning device according to the present invention. For the control device 2 including the controller 3 that requires adjustment of parameters for controlling the controlled object 4, the control characteristic analysis means (first means) 11 adjusts the currently set parameters for the system including the controlled object 4. Analyze control characteristics. This characteristic analysis is performed by applying a test signal such as a step waveform to the control device 4. This test result is input to the control characteristic analysis means (first means) 11 as a control amount feed/<-7 amount. Characteristic values such as rise time, settling time, overshoot, and offset are calculated from the input control amount waveform, and the calculation results are provided to parameter estimating means (second means) 12.

In this parameter estimating means (second means) 12, an adjustment parameter for adjustment by the control device 2 is estimated according to a predetermined rule as shown below.

(Rule 1a) 2. If there is an overshoot, reduce the value of 1<Rameter 1.

(Rule lb): If there is no overshoot, increase the value of parameter 1.

(Rule 1c): If the settling time is slow, increase the value of Sarameter 2.

(Rule 1d): If the settling time is fast, parameter 2
Decrease the value of

The output of this second means 12 is input to adjustment parameter transition output means (fourth means) 14. The fourth means 14 determines the trajectory of the parameter change in the adjustment process, and the adjustment state determining means (fifth means) 15 determines the adjustment state based on the result. The adjustment state determining means (fifth means) 15 makes the following determinations based on the trajectory of changes in the values of each parameter.

(Judgment a): The way each parameter changes is the same over and over again.

(Judgment b): The way each parameter changes oscillates around a certain value.

(Judgment C): The way each parameter changes is small.

(Judgment d): Fine adjustment is required for each parameter individually.

(Judgment e): The controlled object is special and cannot be adjusted using predetermined rules.

Among the above judgments, in the case of (determination e), the adjustment parameter selection means (sixth means) 16 selects the adjustment parameters that are more important for the control system to be adjusted. In addition, in the case of other determination results by the adjustment state determining means 15, the adjustment correction means (seventh means) 17 performs correction according to the following rules.

(Rule 2a): In the case of determination a, it is determined that the rate of change in the parameter is small, and the rate of change is increased.

(Rule 2b): When determining, it is determined that the rate of change in the parameter is large, the rate of change is made small, and fine adjustments are made. It also estimates the convergence value that is the center of vibration and outputs that value.

(Rule 2c): In the case of decision C, the changes are made smaller in order to make final adjustments to the parameters.

(Rule 2d): In the case of judgment d, changes in each parameter are reduced in order to fine-tune each parameter according to the judgment result.

According to the auto-tuning device configured as described above, parameters can be adjusted quickly and with high accuracy according to the adjustment situation.

FIG. 2 shows a second embodiment of the invention. In this embodiment, an information storage means (eighth means) 1g for storing information about the controlled object 4 is provided. It is assumed that the information storage means 18 stores the rating and control specifications of the controlled object 4, and the adjustment results thereof. The ratings and control specifications are manually input by the person adjusting the controlled object, and other adjustment results are automatically stored. A search means (ninth means) 19 retrieves and outputs some data similar to the rating and control specifications of the controlled object 4 currently being adjusted from among the data stored in the information storage means 18. If there is a difference in the adjustment specifications or ratings currently being adjusted, the parameter estimation means (first Q means) 20 performs estimation according to the following rules.

(Rule 3a): If the detected control specification is faster than the one currently being adjusted, increase the value of parameter 1.

(Rule 3b): If the detected control specification is slower than the one currently being adjusted, reduce the value of parameter 1.

(Rule 3c): If the detected rating is larger than the one currently being adjusted, increase the value of parameter 2.

(Rule 3d) If the detected rating is smaller than the one currently being adjusted, reduce the value of parameter 2.

Note that these rules are not limited to -, and may be changed as appropriate depending on the type of adjustment element to be adjusted. The estimated value by the parameter estimation means 20 is adjusted by the adjustment correction means (seventh
means) 17. The adjustment correction means 17 outputs the estimated value of the parameter estimating means 10 as the set value of the adjustment parameter only when a test run has not yet been performed for adjustment.

By configuring as described above, the initial value of the adjustment parameter can be set to an appropriate value.

In addition, since adjustment record data is stored, more appropriate values can be set by repeating adjustments. Therefore, settings can be made that are close to the final adjustment result to some extent, and the adjustment time can be further shortened. Furthermore, since inappropriate values are not set, it is possible to prevent the control system from becoming unstable.

〔Effect of the invention〕

As described above, according to the present invention, by providing a judgment means for judging data in the estimation process and making corrections according to the judgment, it is possible to shorten the time for parameter adjustment and perform highly accurate adjustment. can. In addition, by storing the adjustment results in association with data such as control specifications and ratings that are known before the adjustment, appropriate initial values can be set.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of an auto-tuning device according to the present invention, FIG. 2 is a block diagram showing a second embodiment of the present invention, and FIG. 3 is a block diagram of a conventional auto-tuning device. It is. 2... Control device, 3... Controller, 4... Controlled object, 11... Control characteristic analysis means (first means),
12...parameter estimation means (second means), 13.
...adjustment parameter setting means (third means), 14...
- Adjustment parameter transition output means (fourth means), 15.
...Adjustment state judgment means (fifth means), 16.Adjustment parameter selection means (sixth means), 17.Adjustment correction means (seventh means), 18.Information storage means ( 8th
), 19... similar data search means (ninth means), 10... parameter estimation means (first (l means)
.

Claims (1)

[Scope of Claims] 1. A first means for examining the characteristics of a control system including a controlled object in order to adjust control parameters in components necessary for controlling the controlled object, and the investigated characteristics A control system comprising: a second means for estimating a more appropriate value of a parameter of a control system according to a predetermined adjustment rule; and a third means for newly setting a value of the parameter to a component being adjusted. In the automatic tuning device for control parameters of the device, a fourth means stores the estimation process of the second means and outputs a parameter transition trajectory, and a fifth device determines the adjustment state from the parameter transition trajectory.
means, a sixth means for selecting an adjustment parameter when it is determined that adjustment is necessary as a result of the determination by the fifth means, and the fourth means, the fifth means, and the sixth means. and a seventh means for correcting the estimation result of the second means based on each output of the control parameter auto-tuning device. 2. an eighth means for storing data indicating adjustment results of control parameters based on the output of the seventh means in combination with data indicating known operating conditions such as control specifications; A ninth means for searching data similar to the current operating conditions from among the stored data, and a tenth means for estimating adjustment parameters using the similar data searched by the ninth means. 2. The control parameter auto-tuning device according to claim 1.