JPH0325505A - Multifunction controller - Google Patents

Abstract

PURPOSE:To perform the robust control of quick response by providing a command input part for quick response, a feed forward compensating part, and an equivalent disturbance compensating part which compensates variance elements such as the load variance and the parameter variance which have an influence upon the operation characteristic of a control object. CONSTITUTION:A command input R is changed by the operation of a command setter or the like and is outputted as a command output (r) through a command input part 3. A deviation (e) between the final command input (r) and an output Y as a part of the state variable is subjected to stabilizing compensation by a PI controller 1 or the like to obtain an output T*(S). This output is multiplied by a gain KT by passing a power actuator and is applied to a control object 2. In the end forward compensation, the final command (r) is inputted and the output is added to the stabilizing compensation output. In the equivalent disturbance compensation, T*(S) and Y are inputted and the operation result is added to the output of stabilizing compensation. Thus, quick response and robust stable operation are possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stabilizing feedback control device, and particularly to a multifunctional control device that is robust and can achieve high-speed response.

[Conventional technology]

An example of a general motor speed control system will be explained with reference to FIG.

FIG. 7 shows a conventional example of a stabilizing feedback control device, in which 1 is a PI control device and 2 is an object to be controlled. Here, R and Y are a setting input and a state quantity, respectively. Therefore, in the speed control system example, R is a speed command and Y is a speed detection output. KT is a torque generation coefficient.

That is, the speed control system is stabilized by applying the deviation e between the set human power R and the state fiY to the controlled object through the PI compensation element. The general stabilization adjustment is achieved by increasing the proportional gain KP as the inertia J increases, and increasing the integral gain K accordingly.

As shown in the figure, normally a PI compensation narrow element is inserted in series, and proportional gain KP and integral gain K. Stabilization is achieved by adjusting the

[Problem that the invention seeks to solve]

However, when the proportional gain KP is increased, it tends to become unstable in steady state due to the effects of noise and detection ripples, and when the integral gain KI is increased, the speed may overshoot when the setting input changes stepwise. - This is not preferable because of the occurrence of glitches.

Although it is necessary to change the proportional gain KP + integral gain Kl depending on the operating condition of the motor, etc., in general, the proportional gain K
Since P and the integral gain Kx must be manually adjusted using a variable resistor or the like, it is impossible to adjust them instantaneously depending on, for example, the state of the motor.

Furthermore, there is also a method of automatically changing the integral gain Kx according to changes in the deviation e. Although this method is more functional than the case where the integral gain K■ is fixed, cannot adequately respond to

Furthermore, in order to achieve a faster response, it is necessary to separately add a differential compensation element, but this element is easily affected by noise and the like, and it has always been difficult to stabilize it.

As shown above, the proportional gain K and the integral gain K! Currently, there is no device that can optimally adjust the system according to the operating conditions, and therefore trial run adjusters have to go to the site and make adjustments each time.

[Means for solving problems and their effects]

The present invention has been made in view of the above points,
A stabilizing feedback control system based on PI control has a command input section for high-speed response, a feedforward compensation section, and compensates for variable factors such as load fluctuations and parameter fluctuations that affect the operating characteristics of the controlled object. An exceptional multi-functional control device has been realized, which is equipped with at least an equivalent disturbance compensation section, and in which each device section compensates for the shortcomings of other device sections so that each device section can fully utilize its inherent strengths. It is something.

Hereinafter, the present invention will be explained in detail based on the drawings.

In order to facilitate understanding of the technical idea of the present invention, Figure 1 is shown in Figure 7.
3 is a command input section, 4 is a feedforward compensation section, 5 is an equivalent disturbance compensation section, and Ill.
L is the load disturbance. In the figure, the same reference numerals as in FIG. 7 indicate parts having the same functions.

In other words, with such a structure, the advantages and disadvantages of each part function can be optimally combined and the functions can be effectively used without impairing the advantages of each function. (1) Command input section 3 Practical In the control system of thyristor Leonard. Since the power actuator consisting of an inverter etc. is limited, saturation occurs when an excessive set human power R is input, so there is an integrator installed for high precision operation like the PI control device 1 shown in the figure. Then, while it is saturated, the deviation C
In the process of correcting the deviation, overshoot occurs, which is undesirable for control purposes.

Various solutions to this problem have been announced, but a simple and commonly used method is to stop the integral function while saturation is reached. However, even with this method, some vibration and overshoot occur during the process of canceling saturation, and if adjustments are made to prevent this, there are drawbacks such as a high-speed response cannot be achieved.

Furthermore, if an input is too sudden, the high-speed tracking function of the feedforward compensator 4 of the next block cannot be fully demonstrated.

The command input section 3 is provided to compensate for such drawbacks. Some of these methods aim for high functionality, but when considering practical cost performance, as shown in Figure 2, the acceleration/deceleration time T for the step-like setting human power R is
U. Generally, the command output r of the final command is obtained by adjusting TD.

However, even with such a simple and highly practical method, it is difficult to adjust to the optimal control response when there is a load disturbance or parameter fluctuation of the controlled object, and in the end, it is difficult to adjust the control response to a slow acceleration/deceleration time. is always the case.

(2) The basic control block of the feedforward compensator 4 will be explained with reference to FIG.

In the figure, the same reference numerals as those in the drawing indicate parts having the same function.

The transfer function between the command output r and the output state iY is expressed by the following equation.

Here, if Then, equation (1) becomes ((Y/r)=1).

Therefore, at this time, the deviation becomes (e=o).

That is, the output always follows the input, and the deviation between them is always kept at zero.

However, for this the feedforward Mfitfl
F2 must be in the form of an inverse function of the controlled object O (1/GKt), but if, for example, the inertia J or viscosity coefficient D of the controlled object changes, equation (2) cannot be maintained and control becomes unstable. Sometimes.

(3) Equivalent disturbance compensator 5 This equivalent disturbance compensator 5 operates as shown in FIG.
In the case of speed control, an equivalent disturbance is calculated using the information of torque command) and Y (also rotational output or rotational speed), and this is added to the command T*. moreover,
The functions of the equivalent disturbance compensator 5 will be explained using a block diagram. In the figure, the same reference numerals as in FIG. 1 indicate parts having the same function.

First, in FIG. 4, the case where the equivalent disturbance compensator 5 is not added is shown as follows.

*T (8)K-r-Tt, (8) (JS+D)ω
(S) ..." (3) Here, TL (.S): Load disturbance (S) 2 rotational speed On the other hand, considering parameter fluctuations, the following is set.

However, the marks are nominal values. Δ indicates the variation. , Here, by substituting equation (4) into equation (3), the equivalent disturbance TE(
S) becomes exhausted.

The physical content of this equation (5) is that the equivalent disturbance TE(S) includes all the load disturbance T L (8) and the variation from the nominal value of each constant, etc., and these are collectively called the equivalent disturbance. By considering this, it is shown that it can be described using only the nominal value of each constant, as shown on the right side of equation (5).

Equivalent disturbance compensation is performed by adding this TE(8) to T*(S) through a low-pass filter for noise removal.

Since the time constant of the low-pass filter can generally be made sufficiently smaller than the time constant of the controlled object, FIG. 4 can be rewritten as shown in FIG. 5.

Therefore, as shown in Figure 5, it can be described using only nominal values that are unrelated to load disturbances and constant variations, and the rotational output response to torque commands is not affected by load disturbances or constant variations, so it can be described robustly. Stable operation can be ensured.

Note that the blocks of the equivalent disturbance compensator 5 shown in FIG.
Equivalent transformations can be made on various control programs based on this diagram, and it goes without saying that it is used in a more optimal form in practical terms.

Furthermore, in the present invention, (1) By applying equivalent disturbance compensation, the diagram becomes as shown in the example of the diagram in Figure 5, and the controlled object 2 in Figures 1 and 3 becomes a relational expression of only nominal values. Since the aforementioned adjustment of the command input section does not change the controlled object, it is only necessary to make the adjustment once.

In addition, in the feedforward compensation section described above, (G-KT) of the controlled object in equation (2) becomes (G-Kr), so the relationship in equation (2) can always be maintained, and feedforward compensation can always be performed. It will work effectively.

■ The combination of the command input section, feedforward compensation section, and equivalent disturbance compensation section of the three devices mentioned above eliminates the shortcomings of each device's functions and brings out its features.
There are no particular restrictions on the functions of the stabilization compensation device such as PI control of the main control unit.

However, even greater effects can be achieved by combining a so-called variable structure PI control device in which the proportional gain KP and integral gain K of the PI control are changed according to the position on the phase plane of the sliding mode.

Such a machihen structure PI control device is described in detail in the patent application ``Q-variable structure PI control device'' filed in March 2015 by the present applicant, and the explanation will be omitted here. The purpose is to have robustness against load disturbances and constant fluctuations.

However, with only such a variable structure PI control device, if the command input or load disturbance suddenly changes, the sliding mode phase plane will deviate significantly from the origin, and it takes time to correct it to the origin. I end up.

To improve this, by providing a command input section and a feedforward compensation section, it is possible to follow sudden changes in the command input, and by providing an equivalent disturbance compensation section, it is possible to follow sudden changes in the command input, and by providing an equivalent disturbance compensation section, it is possible to follow sudden changes in the command input It is possible to follow constant fluctuations at high speed.

In this way, it can greatly contribute to improving low-speed responsiveness, which is the only drawback of variable structure PI control aimed at robustness, and can be effective.

■ Varying the gain constant of the feedforward compensator according to the position on the phase plane of the sliding mode promotes even more robustness, while improving low-speed responsiveness at the same time as changing the gain constant of the feedforward compensator depending on the position on the phase plane of the sliding mode. This can be achieved by combining an equivalent disturbance compensation section, etc.

■ The command input section, feedforward compensation section, and equivalent disturbance compensation section of the three devices can produce the above-mentioned effects when combined simultaneously, and can also be used in different combinations as necessary for practical use. Of course you can get it.

〔Example〕

Figure 6 shows the main hardware configuration for the main programs shown in Figure 1.

That is, R, which is a command input, is changed by operating a command setting device, etc., and is outputted as a command output r through the command input section 3.

Deviation e between final command input r and output Y, which is part of the state quantity
is subjected to stabilization compensation by the PI control device 1 and the like, and the output becomes T*(8). T*(81 is applied to the controlled object 2 by passing it through the power actuator, multiplying it by the gain KT.

In feedforward compensation, the final command r is input and its output is added to the stabilization compensation output.
In equivalent disturbance compensation, T*(8) and Y are input, and the calculation result is also added to the output of stabilization compensation.

Although cpty can be implemented using a general-purpose CPU, if a faster response is required, a digital signal processor,
If a digital signal processor (DSP) is used, this can be achieved with sampling of about 50 (μS).

〔Effect of the invention〕

As explained above, the present invention provides a command input section to specifically eliminate the so-called wind-up phenomenon caused by saturation of integral calculation due to excessive input, and a command input section that quickly zeros out the deviation between the final command input and output. Feedforward compensation section for
By combining the three main functions of the equivalent disturbance compensator to make it robust against load disturbances and constant fluctuations of the controlled object, it is possible to eliminate the shortcomings while retaining the features of each function. A highly practical device that can achieve robust control can be provided.

In particular, if a town-hen structure PI control device is used for stabilization compensation,
It is necessary to always operate near the origin of the phase plane in the sliding mode when responsiveness is required, and such a desire can be satisfied.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the main structure shown to facilitate understanding of the technical idea of the present invention, Fig. 2 is a diagram shown to explain the operation of the command input section, and Fig. 3 is a feed forward compensation section. 4 is a block diagram shown to explain the equivalent disturbance compensator, FIG. 5 is a block diagram showing the part to be controlled after equivalent disturbance compensation, and FIG. 6 is a block diagram showing the part to be controlled after equivalent disturbance compensation. FIG. 7 is a block diagram showing a conventional PI control system. 2...Controlled object, 3...Command input section,
4...Feedforward compensation section, 5...
...Equivalent disturbance compensation section. Complainant Applicant Toyo Denki Seizo Co., Ltd. Representative Tetsu Uemura 2nd Act 3rd Figure 4th Figure 5 Procedural Amendment (Voluntary) 1. Case Indication Flat Bottom 1 Year Patent Application No. 159863 2. Name of the invention Multifunctional control device 3. Relationship with the case of the person making the amendment

Claims (1)

[Scope of Claims] 1. Stabilization in which the amount of deviation between the command input of a controlled object and the state quantity of the controlled object is applied to the controlled object through a stabilization compensation device consisting of P (proportional), I (integral), etc. The feedback control device includes a command input section configured such that the command input is given according to a state quantity related to the dynamic characteristics of the controlled object, and a command input section configured to input the command input in the form of an inverse function of a mathematical model of the controlled object. A feedforward compensator applies the output of the compensator through the configured compensator, and calculates an equivalent disturbance including variable elements that affect the operating characteristics of the controlled object from the input amount and state amount of the controlled object, and calculates the equivalent disturbance. A multifunctional control device comprising: an equivalent disturbance compensator that adds disturbance to the input side of a controlled object. 2 The proportional gain (K_P) and the integral gain (K_I) of the stabilization compensation device are expressed as a phase plane consisting of the relationship between the deviation amount and its change per time, a change in the deviation amount per time in the phase plane, and sliding. 2. The multi-functional control device according to claim 1, wherein the change is made in accordance with a difference from a mode switching line. 3 Gain (K_F) of the feedforward compensation section
3. The multi-function control device according to claim 2, wherein: is changed in accordance with a difference between a change in the amount of deviation per time and a switching line of the sliding mode.