SU1689920A1 - Adaptive control system for objects, operating with delay - Google Patents

Abstract

The invention relates to self-adjusting control systems and can be used to automate technological processes with a variable gain control object. Such facilities are often found in the energy, chemical and other industries. The aim of the invention is to improve the accuracy of control. The goal is achieved by the fact that the system additionally contains a module allocation unit, a nonlinear element, a unit of nominal coefficient: a serial unit, a second division unit, a second digital-to-analog converter, and an amplifier with a controlled gain factor. 1 il.

Description

The invention relates to self-adjusting control systems and can be used in the automation of technological processes with a non-stationary gain control object, such objects are often found in the energy, metallurgical, chemical and other industries.

The aim of the invention is to improve the accuracy of control.

The drawing shows a structural diagram of the proposed system.

The system contains setpoint 1, adder 2, controller 3, amplifier 4 with controllable gain, control object 5, delay element 6, first 7 and second object models 8 without delay, adjustment block 9, block 10 analog-digital converters, first block 11 division, block 12 multiplication, register 13, unit 14

coefficients, the first digital-to-analog converter 15, the second dividing unit 16, the nominal factor setting generator 17, the second digital-to-analog converter 18, the module allocation unit 19 and the nonlinear element 20. The delay element 6 and the first object model 7 without regard for the delay form the complete model of the control object. As register 13, a memory address register is used with parallel reception and output of information.

The adaptive control system for objects with delay is based on the principle of continuous adaptation of the gain factors of two object models with and without delay and the gain of the controller according to the value of the gain of the control object. In this case, the assessment of the current

cl

WITH

about

00

yu yu

yoo o

value of the gain of the object is carried out according to the algorithm

Kob (TO K „b (you) ITQ w

-CnSGm) W, (D

“.ЛМ 1 | )

where Kob is the estimate of the gain of the control object;

The hob is the output signal of the control object;

Hm is the output of the full model;

Km - gain factor of the object models;

T | and Tm - the current (regular) and previous cycles of adaptation, 1 1,2, 3, ...

The adaptation of the overall gain of the regulator is based on the principle of continuous adjustment of the gain of amplifier 4 with a controlled gain in order to compensate for changes in the gain of the control object. The gain of the amplifier 4 is adjusted according to the algorithm

™ -Ъ & Г) (2)

where Ku is the gain of the amplifier 4;

KN is the nominal value of the gain of the control object,

Thus, when adapting according to the algorithms (1) and (2), the overall gain of amplifier 4 and control object 5 is almost constant and equal to the nominal gain value of control object 5. Adjusting the gain of amplifier 4 according to the algorithm (2) makes it possible to compensate for changes in the gain of the object 5 of the control (the overall gain of the common link from the output of regulator 3 to the output of object 5 is almost constant and equal to the nominal value).

In order for the blocks 11 and 16 of the division not to fail when the Hm (m) is 0, the nonlinear element 20 is included in the system. When the output signal Hm of the first model 7 of the object is below the set level D, the output signal of the nonlinear element 20 has constant minimum value. This eliminates the possibility of obtaining uncertainty by blocks 11 and 16 divisions.

Prior to the start of operation of the proposed system, the code 13 of the adjustment block 9 is entered with the code of the nominal value (KN) of the gain factor of the control object 5, which is set by the setting device 14,

those. at the output of the setting device 14, there is a code combination corresponding to the nominal value Kn of the gain of the object 5 of the control.

Adaptive management system for

objects with delay works as follows.

In the initial position in the register 13 of the adjustment unit 9, the code of the nominal gain value of the object 5 of the control is located. In this case, the output of the second division unit 16 is a code combination equal to one, since the output combination of the setting device 17 also contains a code combination equal to the nominal value K of the gain of the control object 5, As a result, the gain of the amplifier 4 is set to one.

When changing the reference from setpoint 1 or when applying a single jump, the system executes the reference on three control loops, Block 10 of analog-to-digital converters converts output

the signals of the control object 5 and the first model 7 of the object with a given frequency. The binary codes of these signals go to block 11, where their Hob / Hm ratio is calculated. Since the gain of the control objects is always a positive value, the output digital signal of dividing unit 11 is fed to the input of block 19 of the module, the output of which is the ratio

| Hob

I hm

The digital output signal of the module allocation unit 19 is fed to the first input of the multiplication unit 12, to the second input

which receives the output digital signal of the register 13. In block 12 of the calculation, the current value of the gain of the object 5 of the control is calculated by the formula (1). At the output of the block 12

multiplying, we obtain the code combination corresponding to the new (current) gain of the object 5 of the CoBSP control).

By means of the first digital-to-analog converter 15, the gains of models 7 and 8 are adjusted. In this case, a new value of these coefficients is established, which is equal to the current value of the object's gain.

5, whose code is in register 13.

In the second division block 16, the ratio Kn / Cob is calculated. By means of the second D / A converter 18, the gain of the amplifier 4 is adjusted. As a result, the gain of the amplifier 4 becomes equal to the current value Kn / K0b, i.e. The total gain of amplifier 4 and control object 5 is almost constant and equal to the nominal value K of the gain factor of control object 5, which leads to an increase in control accuracy.

Claims (1)

An Adaptive Control System for Latency Objects, comprising a sensor, a series-connected adder and a controller, a series-connected delay element and a first object model without a delay, connected by an output to the first summing input of an adder, connected by a second summing input, first and second subtractors inputs, respectively, with the outputs of the setter, the second model of the object without delay, and the control object, the input of which is connected to the signal input of the second model the object without delay and to the input of the delay element, the block of analog-digital converters, the first input of which is connected to the output of the control object, and the first and second outputs connected to the inputs of the first block, the serially connected multiplication unit, the register and the first digital-to-analog converter connected by output to the control inputs of the first and second models without delay, the second input of the register is connected to the output of the factor setter, and the output to the first input multiplier, first input connected to the output of the control object, in order. that, in order to improve the control accuracy, it contains a module allocation unit, a nonlinear -element and a nominal coefficient unit connected in series, a second dividing unit, a second digital converter, and an amplifier with a controlled gain, the signal input of which is connected to the controller output, and the output is connected to the input of the control object, the input of the divider of the second dividing unit is connected to the output of the register, the output of the first dividing unit is connected to the input of the allocation unit of the module, the output which is connected to the second input of the multiplication unit, the output of the first object model without delay is connected to the input of the nonlinear element, the output of which is connected to the second input of the analog-digital unit converters.