JPS61279903A - Adaptive controller - Google Patents

Abstract

PURPOSE:To secure the stabilized control by checking whether a control system where a controlled system is controlled by an STR is kept under a steady state or not and then calculating a manipulated variable according to said checking result. CONSTITUTION:A function generator 6 produces the feedforward signal to a controlled system with input of the known disturbance 3. while a primary differentiator 4 and a comparator 5 discriminates a steady state and supplies the deciding signal to an STR 2 through the comparator 5. A calculation mechanism 12 for manipulated variable of the STR 2 calculates the manipulated variable (u) from an equation 3 when the output of the comparator 5 is set at value '1' (unsteady state) and then from an equation 4 when the output of the comparator is set at value '0' (steady state) respectively. Then the 2nd term of the right member of the equation 3, i.e., the factor to cause the unstable control is cut out when a steady state is decided. Thus the stable control is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an adaptive control device that can be applied to improve the control performance limits of conventional PID controllers.

[Conventional technology]

An example of a conventional adaptive control device is shown in FIGS. 3 to 5. Here, 5TR (5elf Tun) is used as an adaptive control device.
ing fl, egulator) f pick up 0
The drawback of the conventional control method is that, as shown in the operation amount calculation mechanism II of FIG. Results that diverge over time may be obtained and the controlled object may become unstable. Toguni originally,
The problem is that unstable behavior occurs when it should be in a steady state.

In Figures 3 to 5, %l is the controlled object, 2 is S
TR, 8 is sampling mechanism, 9 is ARM A moy
” The le creation machine mhio is the time shift mechanism of ARMA-E-7'le, ll is the operation amount calculation mechanism, and 8 to 8 in Fig. 4 are
Details of each part indicated by II are shown in FIG. Also U
indicates the manipulated variable, and y indicates the controlled variable.

[Problem that the invention seeks to solve]

The cause of the unstable control described in the above-mentioned section of the prior art lies in the coefficients in the second order on the right side of equation (3), as shown in the manipulated variable calculation mechanism 11 in FIG. For example, for simplicity b
1=1*bl=2.

~bn * aI”-an k It can be clearly seen when zero. In this case, the first term on the right side of equation (3) of the fifth factor is zero, and the second term is the value of u (t) as follows. This is used as the value of u(t-1) on the right side during the step.

The amount of operation in the next step becomes -2u, and similarly, as the steps progress, it diverges to 4u, 8ue, and so on. As a result, there is a problem that the controlled object may become unstable.

The present invention was proposed in order to solve the above-mentioned conventional problems, and is capable of stabilizing control and is an adaptation that can greatly reduce offset even when switching from a transient operating state to a steady state. The purpose of this invention is to provide a control device.

[Means for solving problems]

The adaptive control device according to the present invention includes, in a control system that controls a controlled object using an STR, a function generator that inputs a known disturbance, and an output of this function generator that is added to the controlled object as a feedforward signal to the STR in a steady state. a means for bringing the manipulated variable output from the output close to zero; and a means for reducing the known disturbance to 1.
A first-order differentiator that performs order differentiation, a comparator that compares the absolute value of the output of this first-order differentiator, and a signal that is regarded as a transient operating state when the value compared by this comparator exceeds a predetermined threshold. is input to the STR, and the STR calculates the manipulated variable that minimizes the variance of the controlled variable one point ahead, and at the stage where the compared value does not exceed a predetermined threshold, a signal is determined to be in a steady state. The present invention is characterized by comprising means for inputting the input into the STR and calculating the amount of operation in a region that can be determined to be a steady state based on the STR.

[For production]

According to the present invention, in order to prevent divergence of the manipulated variable U, the movement of a known disturbance to the controlled object is determined by 1 to determine whether or not it is in a steady state.
When it is detected by the second-order differential circuit and determined to be a steady state,
The second term on the right side of equation c3) of the operation amount calculation mechanism 11 in FIG. 5 of the prior art is cut, and the value t of the first term on the right side is 17b.
l- Regardless of the value identified by the ARMA model creation mechanism 9 in Figure 5, by specifying the '2nd term on the right side so that stable control can be achieved after cutting, control is made unstable in the steady state. Since the root cause is removed, control can be stabilized.

〔Example〕

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows the structure of an embodiment of the present invention! i, the second diagram showing
The figure is a detailed diagram of the STR in FIG. 1.

In Figures 1 and 2, l is the controlled object and 2 is the ST
R, 3 is a known disturbance, and 4 is a first-order differentiator.

5 is a comparator, 6 is a fi function generator, 7 is an adder, 8 is a sampling mechanism, 9 is an ARMA model creation as, and 7 u is a time shift mechanism for the ARMA model.

12 is a manipulated variable calculation mechanism.

The operation of the above embodiment of the present invention will be explained.

In FIG. 1, in a control system in which a controlled object 1 is controlled by 5TR2, a known disturbance 3 is differentiated by a first-order differentiator 4 (T
Compare the absolute value of the value ($, S is the child of Laplace operation 1 + τS, τ is a constant) with the value specified by the comparator 5, and if it exceeds the specified value, the value is 1t-1. Otherwise, it outputs 0 and outputs STR. Then, an adder 7 adds the output of the function generator 6 and the output of 5TR2, which are input to the known disturbance 31, and supplies it to the controlled object I.The function generator 6 inputs the known disturbance 3 (for example, load) and generates a feedforward signal to the controlled object l.5T
R2 is a bump-pull mechanism 8 as shown in FIG. ARM
A feature of the present invention lies in the operation position calculation mechanism 12, which consists of an A model creation mechanism 9, an ARMA model time shift mechanism 10, and an operation i calculation mechanism 2. The manipulated variable calculation mechanism 12 in FIG.
4) Calculate the manipulated variable U using the formula.

However, k in equation (4) is determined by the adjuster through trial and error in order to improve control performance. In addition, since the differential value of the first-order differentiator 4 becomes zero when the known disturbance 3 remains unchanged,
Based on the absolute value of the output of the first-order differentiator 4, it can be determined whether the operation is steady or transient.

〔Effect of the invention〕

According to the present invention, the function generator generates a feedforward signal, and the manipulated variable uf is output from the STR.
In a steady state, it can be set to zero, and it can be determined whether it is in a steady state using a first-order differentiator and a comparator.
For example, the manipulated variable calculation mechanism 12 in Fig. 2 can be switched between the (31 and (4) formulas, stabilizing the control, and even when switching to the (4 formulas), the offset can be minimized. This will bring about the same effect.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention, FIG. 2 is a detailed diagram of the STR in FIG. 1, and FIGS. 3 to 5 are diagrams each showing a conventional example.01...Control Target, 2...
5TR13... Known disturbance, 4... First-order differentiator, 5.
...Comparator, 6...Function generator, 7...Adder, 1
2...Operation amount calculation mechanism. Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 1 Figure 9R2

Claims (1)

[Claims] In a control system that controls a controlled object using an STR, there is a function generator that inputs a known disturbance, and the output of this function generator is added to the controlled object as a feedforward signal, and in a steady state, the manipulated variable output from the STR is zero. a first-order differentiator for first-order differentiating the known disturbance; a comparator for comparing the absolute value of the output of the first-order differentiator; At the stage where the operating state is exceeded, a signal that is considered to be a transient operating state is input to the STR, and from this STR, the manipulated variable that minimizes the variance of the controlled variable one point in time is calculated, and the compared value exceeds a predetermined threshold value. An adaptive control device characterized by comprising means for inputting a signal to the STR that is considered to be a steady state when the state is not exceeded, and calculating an operation amount in a region determined to be a steady state based on the STR.