SU1403014A1 - Production process control system - Google Patents

Abstract

The invention relates to the automatic control of technological processes under the conditions of action of periodic disturbances and can be used in the design of automatic systems for the supply of oxygen to the units of metallurgical production. The aim of the invention is to improve the control accuracy by suppressing periodic disturbances. The control system contains the regulator 1, the sensor 7 of the adjustable parameter, the sensor 2 of the magnitude of the control action, three converters 3, 8, 38, two blocks 4, 10 of the comparison, the controller 5, the object 6 of regulation, the setting parameter 9 of the adjustable parameter, three differentiators 31 -33, two logical blocks 34-35, adder 16 and integrator 17, The essence of the invention is that, by logical processing of the control error signal, the periodic component in its composition is filtered and not passed to the controller input. 3 il. Q S (L

Description

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The invention relates to the automation of technological processes under the conditions of periodic perturbations and can be used in the design of automatic systems for the supply of oxygen to the units of metallurgical production.

The aim of the invention is to improve the control accuracy by iodoad the periodic perturbations. ; The drawing shows the structures 1; 1a diagram of the process control system.

 The system contains a regulating frgan, a sensor 2 of the magnitude of the controllable action, the first converter 3, the first block 4 of comparison, the controller 5, the control object 6, the sensor 7 of the controlled parameter, the second converter 8, the setpoint adjuster 9 of the adjustable parameter, the second block

Compare, first 11, second 12 third 13 differentiators, first

4 and the second 15 logical blocks, the damper 16, the integrator 17 and the third prefixer 18.

; The first 3, second 8, and third 18 prefabers are measuring, which convert the input physical quantities into electrical signals.

The system works as follows. X I The electrical signal from the sensor 7 of the adjustable parameter, after being converted into a unified signal on the second 8 converter, is fed to the second comparison unit 10, where 6N is compared with the signal of the adjustable parameter setting device, after which the error signal is fed to the input of the first differentiator 11 and to the first input of the first logic unit 14, the signal of the second derivative from the output of the second differentiator 12 is fed to the second input of the first logic unit 14. In the case of coincidence of the signs of the signals of the second derivative and the signal The signal at the output of the first logic block 14 corresponds to the error signal, if this condition is not met, then the zero signal at the output of the first logic block 14 is output from the output of the first logic block 14 to the adder 16, where it is summed with the signal of the first derivative. From the output of the adder 16, the signal is fed to the second input

Logic block 15, to the first input of which a third derivative signal is supplied from the output of the third differentiator 13. In the second logic block 15, the output signal of the adder 16 and the signal corresponding to the third derivative are compared to the output of the third differentiator 13. If they coincide, the output signal of the second logical block 15 is equal to the output signal of the adder 16 if the signs are opposite, the signal at the output of the second logical block 15 is equal to zero. The signal at the output of the second logic unit 15 is determined as follows:

Y + a, x, with and + +,) S 0;

Y: a, x, at. x; O and a, X, Xs & ABOUT

I О at x, j: O and a, X, X} -0

or (+ a, x,) where xq, x ,, x, x are respectively

the error signals of the first second and third derivatives;

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amplification factors, respectively, according to the mismatch and the first derivative of the mismatch.

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The signal from the output of the second logic unit 15 is fed to the input of the integrator 17. The electrical signal nor the last signal after conversion to the unified signal in the third converter 18 is used as a reference in the control system. Here, in the first block 4 of comparison, an error signal is generated from the given and the actual intensity and the controller 5 maintains the intensity at a given level, (

With an increase in the control action on the control object 6 (for example, the intensity of blowing in the combustion chamber), the technical process is intensified, which leads to a change in the controlled parameter or its derivative. In this case, a series of processes is characterized by the presence of a periodic external action. For example, in the case of a combustion chamber, after ignition, heat is generated, the amount of which is a function of time and is proportional to the mass of fuel that reacts at a given time. As the fuel burns out, the heat release per unit time decreases. Thus, the discrete supply of fuel is a factor causing the appearance of a periodic external disturbance of the controlled parameter — the temperature of the working space. This external disturbance can be represented as a certain function f (t), which is a harmonic or close to it function when the fuel is being fed rhythmically. When the above conditions are met, the effect at the input of the integrator 17 is zero.

Thus, the change in the magnitude of the control action, and, consequently, the reactions of the whole system to the external action f (t) associated with the discrete perturbation, will be from-. will be absent or in any case will be weakened. The control error is determined by the deviation of the controlled parameter to this disturbance, as well as by the selection of the control parameters aj and a (. When changing the set value from the setting parameter setting 9 or the appearance of an external influence, the character of which is different from f {t), the control action will be made taking into account the inertia of the control object 6, ensuring sufficient accuracy and speed of parameter control (in the considered example - temperature in the combustion chamber).

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Claims (1)

Claims of the Invention: A process control system containing a control object, the first input of which is an input of a periodic perturbation signal, a second input connected to the regulator output, the output of the control object through a series-connected adjustable parameter sensor and a second converter connected to the input of the second comparator unit, the second the input of which is connected to the unit of the regulated parameter, the second output of the regulator through the sensor of the magnitude of the control action The first converter is connected to the input of the first comparison unit, the output of which is connected through the regulator to the regulator's input, characterized in that, in order to increase control accuracy by suppressing periodic disturbances, it additionally contains 5 three differentiators, an adder, the first and the second logic blocks, the output of the second logic block through the serially connected integrator and the third converter are connected to the second input of the first comparison block, the output of the second comparison block is connected to the input of both the first differentiator and the first logic block, the second input of which is connected to the output of the second differentiator, and the output of the first logic block is connected to the input of the adder, the second input of which is connected to the output of the first differentiator, which is connected to the input of the second differentiator, the output of which is connected to the input of the third differentiator, the output of which is connected to the input of the second logic unit, the second input of which is connected to the output of the adder. 0 five 0