JPH0378806A - Multi-function type controller - Google Patents

Abstract

PURPOSE:To eliminate the mutual interference between the variable structure PI control and the equivalent disturbance compensation control and to attain the stability of a multi-function type controller by providing a function which varies the equivalent disturbance compensation value based on the deviation value. CONSTITUTION:A function signal generating part 6 is provided at the output side of an equivalent disturbance compensating part 5, and the equivalent disturbance compensation output is varied based on the deviation (e) and fed back. In other words, the deviation (e), i.e., the input of a variable structure PI control part 1 is detected. Then the equivalent disturbance compensation is stopped when the deviation (e) is large, and the deviation (e) is settled by the variable structure PI control only with no overshoot. When the deviation (e) is set at a certain level or less, the equivalent disturbance compensation is carried out again. At the same time, a proportional coeffi cient K which varies the equivalent disturbance compensation value by the deviation (e) is turned into a function. Thus it is possible to suppress the mutual interference between a variable structure PI controller and an equivalent disturbance compensating part without deteriorating the characteristics of control functions of both parts via the control of the equivalent disturbance compensation value carried out just with supplication of a relational formula (K - e).

Description

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

[Conventional technology]

Regarding the multi-machine egg-shaped control device according to the present invention, the present applicant has previously proposed a patent application titled "Variable Structure PI Control Device" filed on March 27, 1999.

An example of a further proposal is shown in FIG.

Figure 3 shows an example of an earlier proposal by the applicant.
1 is a variable structure PI controller.

That is, the proportional gain Kp and the integral gain Kx are expressed as a phase plane consisting of the relationship between the deviation e between the set human power R input as an instruction value to the controlled object and the state quantity of the controlled object 2, and its change per time. The change is made in accordance with the difference between the change in deviation in the phase plane over time and the switching line of the sliding mode.

Furthermore, the present applicant has separately proposed a patent application ``Multi-machine serpentine control device'' dated June 1, 1999. An example of another proposed method is shown in FIG.

FIG. 4 shows an example of another previous proposal by the present applicant, in which 3 is a command input section, 4 is a feedforward compensation section,
5 is an equivalent disturbance compensation section.

That is, in particular, the variable structure PI control device 1. The feedforward compensator 4 and the equivalent disturbance compensator 5 are used in combination to realize a device that is robust to the control system and capable of high-speed response.

A detailed explanation of FIG. 4 will be omitted, and only each part will be described as follows. ■ Command input section 3 In a practical control system, a power actuator consisting of a thyristor Leonard, an inverter, etc. Since R is finite, saturation will occur if an excessive setting human power R is applied, and if there is an integrator installed for high precision operation like the variable structure PI control device 1 shown in the figure, saturation will occur. Since the deviation e is integrated during the interval, an oversheet occurs in the process of correcting the deviation, which is unfavorable in terms of control. Also,
If too sudden an input is applied, the high-speed tracking function of the feedforward compensator 4 of the next block cannot be fully demonstrated.

In the end, the acceleration/deceleration time 'r
Generally, Ua'rD is adjusted to obtain the command output r of the final command.

■ Feedforward compensation unit 4 In the transfer function between the command output r and the output state quantity 7, if it is expressed in the form of a function of the controlled object (G) (1/GK7), then ((Y/r) = 1). . Therefore, at this time, the deviation becomes (e=0), the output always follows the input, and the deviation between them is always kept at zero. However, if the inertia J or viscosity coefficient of the controlled object fluctuates, control may become unstable.

■ Equivalent disturbance compensation unit 5 * Configured by calculating the equivalent disturbance using the information of the command T (torque command in the case of speed control) and Y (also rotational output or rotational speed) and adding this to the command T be done.

Then, as described later, equation (3) is obtained based on equations (1) and (2).

*T (S)KT-Tt, (8) = (J8+D)-(S
)...(1) TL(S): Load disturbance ω(S) 2 Rotational speed Here, considering parameter fluctuations, the following is set.

However, the 4 marks indicate the nominal value, and Δ indicates the variation.

Tz(8)=T*(8)・K, −(JS+D)・−C8
) ......(3).

Therefore, the physical content of equation (3) is that the equivalent disturbance Tg (8) includes the load disturbance TL (8) and the fluctuations from the nominal value of each constant, etc., and these are grouped together to form the equivalent disturbance. By considering this, it is shown that ° can be described using only the nominal value of each constant, as shown on the right side of equation (3).

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

[Problem to be solved by the invention]

In the variable structure PI control device as described above, the deviation e
When becomes large, the sliding mode phase front is controlled by a proportional gain by switching the polarity of and converging to the origin along the switching line. At this time, a chattering phenomenon occurs, which is a drawback of the sliding mode.

It is clear that this chattering phenomenon occurs also from the principle of variable structure PI control, and when the cause of this chattering phenomenon occurs, which is the output that repeats forward and reverse from the variable structure PI control device, the The equivalent disturbance compensator directly receives the influence of this previous stage output, resulting in excessive vibration input and interference, which causes stability. This may slow down the process or cause sustained vibration.

In other words, the magnitude of the proportional gain is variable depending on the polarity switching order of the proportional gain Kp and the deviation from the switching line, so when the deviation e is large and crosses the switching line, the output is also large and the polarity changes instantly. Therefore, the subsequent equivalent disturbance compensator generates an oscillating compensation output with switched polarity in order to compensate for this. This output is further compensated by addition to the variable structure PI controller output, thus causing mutual interference,
As a result, there may be a delay in response compared to a fixed PI control device.

The present invention has been made to eliminate the above-mentioned problems, and the present invention will be explained in detail below.

[Means to solve the problem]

Therefore, as a means for eliminating the above-mentioned mutual interference, the present invention is provided with a function signal generation section particularly arranged on the output side of the equivalent disturbance compensation section, thereby preventing mutual interference between the variable structure PI control and the equivalent disturbance compensation. Alternatively, by providing means for feeding back the equivalent disturbance compensation output as variable depending on the value of the deviation e in order to suppress the disturbance, it is possible to achieve the advantages of both control functions without impairing them.

[For production]

With this solution, the deviation e which is input to the variable structure PI control unit is detected, and the equivalent disturbance compensation output is controlled based on this detected amount.

That is, when the deviation e is large, the equivalent disturbance compensation is stopped, and settling is performed without oversheeting only by variable structure PI control, and when the deviation e becomes less than a certain amount, the equivalent disturbance compensation is restored. Alternatively, it may be made to be inversely proportional to the deviation.

Here, by converting the proportionality coefficient K, which makes the equivalent disturbance compensation amount variable according to the deviation e, into a function, one equivalent disturbance compensation amount can be controlled by simply introducing the simple relational expression (K-e). By acting to perform this, mutual interference can be suppressed without causing any practical problems.

〔Example〕

FIGS. 1 and 2 show the main part configuration of an embodiment of the present invention and the function output characteristics of its function signal generation circuit,
6 is a function signal generation circuit. In the figure, the same reference numerals as in FIG. 4 indicate parts having the same functions.

That is, in FIG. 1, a function signal generation circuit 6 is provided which obtains two input signals, particularly the outputs of the deviation self and the equivalent disturbance compensator 5, and generates the signals to the adder.

Here, the system shown in FIG. 1 has the same configuration as that shown in FIG. 4 except for the addition of the function signal generating circuit 6, and detailed explanation thereof will be omitted. Next, the function of the function signal generating circuit 6 will be explained with reference to FIG.

The function signal generation circuit 6 makes its output variable depending on the value of the deviation e which is the input of the variable structure PI control device l, and further multiplies the output of the equivalent disturbance compensator 5 by the own function signal generation signal. It sends out signals. The function generation function is shown in FIG.

That is, in FIG. 2(a), the deviation e is the limit.

When (0<e<α), the coefficient output Kc is (
Kc=1), (α<e<β), the deviation e
An example is shown in which the coefficient output Kc attenuates in proportion to the magnitude of , and reaches zero.

Furthermore, in Fig. 2(b), when (o<e<α), the coefficient output Kc is (Kc=1), and when (8>α), the coefficient output Kc is attenuated in inverse proportion to the deviation e. An example is shown.

Therefore, the function signal generation circuit 6 having such a coefficient output Kc of the function generation part multiplies the coefficient output K by the equivalent disturbance compensator 5 and sends a signal to the variable structure P.
To prevent mutual interference between the I control device 1 and the equivalent disturbance compensator 5,
This can be effective in stabilizing control.

Here, since the command input section 3 and the feedforward compensator 4 can follow sudden changes in the setting input hole, the deviation e, which is the input to the variable structure PI control device l, becomes small, but it When there are fluctuations in the setting manual force B, inertia J, and viscosity coefficient, the deviation becomes large, and by providing such feedback means, the control system can be stabilized more quickly.

〔Effect of the invention〕

As explained above, according to the present invention, by having the function of making the equivalent disturbance compensation amount variable depending on the amount of deviation,
It is possible to provide a practically useful device that eliminates mutual interference between the variable structure PI control and the equivalent disturbance compensation control and achieves stabilization without impairing the features of both control systems.

Furthermore, by using a method that takes the relationship between the coefficient K and the deviation e,
Needless to say, adjustment is extremely easy.

Furthermore, the equivalent disturbance compensation section of the variable structure PI control device 9 has a command input section and a feedforward compensation section, and while controlling the deviation e to be as small as possible, the inertia and viscosity coefficient fluctuation time function signals of excessive input are provided. It is clear that the generation function works effectively and the stable operating region can be expanded.

[Brief explanation of drawings]

Fig. 1 and Fig. 2 are a system diagram showing the main part configuration of an embodiment of the present invention and a function output characteristic diagram of its function signal generation circuit, and Fig. 3 explains the previous proposal by the applicant. FIG. 4 is a block system diagram shown to explain another previous proposal by the applicant. 1...9 quality structure I) I control device, 2...
...Controlled object, 3...Command input section, 4...
... Feedforward compensation unit, 5... Equivalent disturbance compensation unit, 6... Function signal generation circuit, e...
... Deviation, Kc ... Coefficient output.

Claims (1)

[Claims] 1. A phase plane consisting of the relationship between the command input of the controlled object and the amount of deviation from the state quantity of the controlled object and its change per time, the change in the time period of the deviation amount in the phase plane, and the switching line of the sliding mode The proportional gain (
Kp) and integral gain (K_I), and a variable structure PI control unit that changes the input amount and state amount of the controlled object to calculate an equivalent disturbance including variable elements that affect the driving characteristics of the controlled object. an equivalent disturbance compensation unit that adds the command input to the input side of the controlled object; a command input unit configured such that the command input is given according to a state quantity related to the dynamic characteristics of the controlled object; a feedforward compensator that applies the output of the compensator through a compensator constructed in the form of an inverse function of a mathematical model; A multi-functional control device characterized in that it is provided with a function signal generating section that generates a signal as a command output value.