SU1536352A1 - Combination control system - Google Patents

Abstract

The invention relates to the control of general purpose systems, in particular automatic electrical controllers. The purpose of the invention is to improve the accuracy of the system and improve the technical feasibility of the applied parameters, in particular the gain of the inertial control object. The increase in accuracy is achieved by identifying the reciprocal of the gain of the control object and the corresponding change with the help of multiplication blocks of the gain factors of the open-loop and closed-loop controllers of the driver distribution. 1 il.

Description

This invention relates to the management of general purpose systems, in particular, automatic electric regulators.

The purpose of the invention is to improve the accuracy of the system and improve the technical feasibility of the applied parameters, in particular, the gain of the object.

The drawing shows a block diagram of the system.

The system contains the first adder 1, the differentiator with the force 2, the PID controller 3, the second adder 4, the control object 5, the first 6 and second 7 low-pass filters of the second order, the integrator with delay 8, the first 9 and the second 10 rectifiers

with the dead zone, the first 11 and second 12 low-pass filters of the first order, dividing unit 13, upper and lower limiter 14, the first 15 and the second 16 multiplication blocks.

In the drawing, the following notation is accepted: F3 - specifying effect on the system} Z - output signal of the control object; F - disturbing effect; F l is the desired type of transient, X is the system error signal, Kof (t) is the variable gain of the control object; U- control signal; U is the signal at the integrator output with a delay.

Elements 1-13 of the system are implemented with the help of multi-functional

oo

is smiling

GO

SP

Yu

automatic control devices.

The system works as follows.

The specifying effect F3 enters the first low-pass filter input of the second order 6, which forms the desired type of transient F # (t) No. then goes to the main control loop. The regulator of the main control circuit J, containing blocks 16 and 3, is built on the basis of the conditions of the highest perturbation of perturbations F (t) acting on the object 5 of the control.

The second low-pass filter of the second 1 (J 7 for this circuit is introduced to ensure the condition of physical realizability of the differentiator with forcing 2 by the inertial control object 5. Let, for example, the control object 5 is described by 2) The transfer function of the inertia ({shny integrating link

w (pt Kpy (fc) ..

Vp; p (To5p + i) 2

In accordance with the condition of absolute invariance

t

“T (P) .HK (P,

t.e. Block 2 does not meet the conditions of physical feasibility, since the indicator of the degree of its numerator exceeds the exponent of the denominator.

If, however, in the proposed device, we select the transfer functions of the low-pass filters of the second order 6 and 7

W, (P) W, (P).

Where T „and

f - respectively, the desired time constant and damping factor

one

"Rfw-t-sh

w4 (p) - + O,

When the equivalent link W9 (P), BHS- Divided in the drawing by a dotted line, corresponding to the serial connection of blocks 15, 2 and 14, is responsible for catching physical realizability

W, (P) -) -

50

PCTpgP + 1)

 + 2 (ЖТЖР + 1

In this case, the zero error of the system X from the setting action Fj (P) is ensured.

In the absence of a disturbing effect

Z (P) - F3 (P) W, (P) W, (P) - F3. t

.with;

p (l)

0 "

Kftg (t)

(T +1) P (T0, rP + 1)

x

-FX (P); X (P) -F (P) -Z (P) - 0

Blocks 8-13 are intended to identify K (t), the reciprocal of the gain of the control object 5. An integrator with a delay of 8 is introduced to eliminate the effect of the dynamic delay of the control object 5 in identifying the reciprocal of its gain factor:

Wft (P)

one

P (T06P + 1)

Dividing the U and Z signals in the absence of noise and negligibly small discrepancies in the dynamics of the Wy and We blocks gives the value of (t);

U (P) „U (P) W, (P)

Z (P)

U (P) W5 (P)

0

five

five

0

 P (TogP -f I) v-VM

p (tolr +)

In the presence of high-frequency interference and the mismatch of the dynamics of the blocks W.

ABOUT

and W ,. (which in practice can always occur) with the direct division of the signals U and Z there can be significant fluctuations in their quotient, i.e. signal (t). As a result, it is necessary, before applying these signals to the dividing unit 13, to pre-straighten them and smooth them out, which is done by blocks 9, 10 and H, 12.

The signal (t) from the output of dividing unit 13 is limited at the top and bottom by a limiter 14 of the upper and lower levels in accordance with a priori information about the possible range of variation of the gain.

K0j (t) of object 5 and is fed to the inputs of blocks 15 and 6 of multiplication. The presence of block 14 increases the reliability of the system in case of failure of the identification circuits (blocks 8-13) of the inverse value of the gain factor (t) of the control object 5. During normal operation of these circuits, this block limits the result of the division at the output of block 13 with zero and small signals at its inputs.

Multiplication unit 16 eliminates the effect of variable gain.

object 5 to the transfer function of the Pa-15 conditions of technical feasibility

closed: the main circuit, which facilitates ensuring the stability of this circuit in a closed state with sufficiently large gains and the presence of additional small delays inherent in the dynamics of a real control object 5. Ultimately, this also leads to an increase in the accuracy of the system as a whole.

In order to preserve the operability of dividing unit 13 in order to prevent the division of very small signals, rectifiers 9 and 10 are made with dead zones ldi & ten . When the rectifier input signals decrease below the set level, their output signals have the minimum allowable values. The ratio l / d, „

/-one

25

thirty

TO

about

19 is chosen to be equal to the most variable parameters of the control object, and the upper and lower limiter

20 is leveled to the output of which the first inputs of the first and second multiplicators are connected, the system input is connected via the first low-pass filter of the second order, to the non-inverting input of the first adder whose output is connected to the second inlet of the second multiplication unit connected to the PID input the controller, the output of the differentiator with the forcing is connected through the second low-pass filter of the second order to the second input of the second adder, the input of the first filter of the lower frequencies of the second order is connected to the second input of the first control unit Multiplying the output of which is connected to the input of a differentiator with force, the output of the second adder through a serially connected integrator with an inverse, for example, mean value K of the inverse value of the object gain from the range of its variation.

The multiplier 15 is introduced to improve the accuracy of the system by eliminating the effect of the variable gain factor K0s (t) of object 5 on the condition of absolute invariance in the second propagation channel of the reference effect FJ.

The proposed system can be used for high-precision control.

Claims (1)

laziness by industrial facilities under varying working conditions. Invention Formula A combined control system containing the first adder, the inverting input of which is connected to the output of the control object and the output of the system, a differentiator with forcing, a PID controller connected through the second adder to the control object's input, so as to improve the accuracy of the system and improve five 0 applied parameters of the control object, sequentially connected division block and upper and lower limiter are entered into it 0 is level, to the output of which the first inputs of the first and second multiplication units are connected, the system input is connected via a first low-pass filter of the second order, to the non-inverting input of the first adder, the output of which is connected to the second input of the second multiplication unit, output connected to the PID input. - gullet, the differentiator output with forcing is connected through the second low-pass filter of the second order with the second input of the second adder, the input of the first low-pass filter of the second order is connected to the second input of the first About the multiplication unit, the output of which is connected to the input of the differentiator with force, the output of the second adder through the serially connected integrator with delay, the first rectifier with the dead zone and the first low pass filter of the first order are connected to the first input of the division unit, the system output through follow 5, the second rectifier is connected to the dead band and the second low pass filter of the first order is connected to the second input of the division unit.