RU2788576C1 - Jet-photocompensation semi-continuously operating proportional-integral-differential (pid) regulator - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to jet-photocompensation regulators. The jet-photocompensation semi-permanently operating proportional-integral-differential regulator consists of a proportional-integral PI-regulator and a differentiating link, and the PI-regulator includes input nozzles normally located to the sensing element: the plate, the angle of rotation of which is proportional to the force action of the jets and is recorded by the optical part of the regulator, consisting of a light source, a condenser, a diaphragm and a dual photo resistance cell, entering into an equilibrium electric bridge, in the feedback of which there is a magnetoelectric galvanometer, a resistance divider for changing the gain, an output milliammeter for registering the output signal and an integral link consisting of electrical capacitor and variable resistance to change the integration time constant, it is characterized by the fact that the differentiating link consists of a pneumatic variable resistance, a constant volume, a single-membrane precision repeater and a nozzle located on the plate of another magnetoelectric galvanometer, the output of which is combined with an adder with a PI regulator, at the output of which there is a node for forming a control command to turn off the regulator when the adjustable value and its speed deviate from the task, performed in in the form of a disconnecting relay with two parallel threshold elements, moreover, the first threshold element is connected to the output of the regulator to determine the error sign, and the second threshold element is connected to the differentiating link to determine the speed sign.

EFFECT: linearity of the static characteristic and the dynamics of the control process are provided.

1 cl, 2 dwg

Description

The invention relates to the field of pneumoelectric automatic regulators.

The prior art pneumatic proportional-integral-derivative (PID) controller, consisting of a membrane proportional-integral (PI) controller and a differentiating link, combined with an adder [1]. The PI controller includes a proportional link containing a comparison element, in the feedback of which there is a divider consisting of variable and constant resistances, a change in the conductance ratio of which leads to a change in the gain of the input pressure difference. The integral and differentiating links are made on the basis of aperiodic links, consisting of a constant volume and a variable resistance to change the time constant.

The disadvantages of such a regulator are the low dynamic properties inherent in the membrane elements.

The technical result achieved in the present invention is to increase the speed of regulation by using the principle of a semi-permanently operating regulator [1] and a compensation scheme based on the equality of the moments of the force action of the jet on the moving barrier and the counteracting magnetoelectric force.

A proportional regulator is also known, consisting of a movable part, including a plate suspended on a gas support, an input differential pneumatic circuit, a reading element in the form of a “nozzle-shutter” type assembly, a pneumatic membrane power amplifier covered by regenerative feedback [2]. The principle of operation of this solution, as well as the present invention, is the use of a measuring compensation circuit based on the force action of the jet on a moving barrier, however, the present invention implements the controller in a semi-constant PID controller mode, which significantly increases its speed.

More specifically, the technical result is achieved by the fact that the jet-photocompensation semi-permanently operating proportional-integral-differential controller consists of a proportional-integral PI controller and a differentiating link, and the PI controller includes inlet nozzles normally located to the sensing element - a plate, the angle of rotation which is proportional to the force effect of the jets and is recorded by the optical part of the regulator, consisting of a light source, a condenser, a diaphragm and a dual photoresistance included in an equilibrium electric bridge, in the feedback of which there is a magnetoelectric galvanometer, a resistance divider for changing the gain, an output milliammeter for recording the output signal and an integral link, consisting of an electric capacitor and a variable resistance to change the integration time constant, characterized in that the differentiating link, consisting of a pneumatic their variable resistance, constant volume, a single-membrane precise follower and a nozzle located normally to the plate of another magnetoelectric galvanometer, the output of which is combined by an adder with a PI controller, at the output of which there is a unit for generating a control command to turn off the controller when the controlled value and its speed deviate from the target , made in the form of a trip relay with two parallel threshold elements, the first threshold element is connected to the controller output to determine the sign of the error, and the second threshold element is connected to the differentiating link to determine the sign of the speed.

. Рамка 12 гальванометра 5 помещена в поле постоянного магнита 13, образуя при протекании тока I обратной связи магнитоэлектрический момент направленный встречно механическому моменту от силового действия струй на поверхность пластины 3.In FIG. 1 shows a diagram of a jet-photocompensation semi-permanently operating proportional-integral-differential (PID) controller, consisting of a proportional-integral (PI) controller 1 and a differentiating link 2 . To register the angle of rotation of the sensitive element - plate 3 , fixed on the loop 4 of the photoelectric galvanometer 5 , an optical circuit is provided, consisting of a mirror 6 , on which a light beam falls from a source 7 , a condenser 8 and a diaphragm 9 . The beam of light reflected from the mirror illuminates both halves of the dual photoresistance 10 included in the equilibrium bridge 11 formed by resistances

. The frame 12 of the galvanometer 5 is placed in the field of a permanent magnet 13, forming a magnetoelectric moment directed opposite to the mechanical moment from the force action of the jets on the surface of the plate 3 when the feedback current I flows.

In the feedback of the PI controller, a divider 14 is arranged in series to change the gain of the proportional link, an output secondary device is a milliammeter 15 , an output resistance 16 and an electrical integral link consisting of a capacitor 17 and a variable resistance 18 . By changing the conductivity α of the variable resistance 18 , you can change the integration time constant:

(1)

(1)

- емкость конденсатора 17,

- универсальная газовая постоянная,

- абсолютная температура.where

- capacitor capacitance17,

- universal gas constant,

-absolute temperature.

переменной величины и давлению

задания.The input channel of the PI controller is represented by two nozzles 19 and 20 , from which jets flow under pressure proportional to the pressure

variable and pressure

tasks.

дифференцирования. Для получения расходного сигнала, пропорционального производной входного давления

переменной величины используется точный повторитель 23, питание которого осуществляется через постоянный дроссель 24. Изменением проводимости β переменного сопротивления 22 можно менять постоянную времени дифференцирования:The link of the differentiating converter (the same numbering of the same type circuit components was used) consists of a pneumatic capacitance 21 and a variable resistance 22 for changing the time constant

differentiation. To obtain a flow signal proportional to the derivative of the inlet pressure

variable value, an exact follower 23 is used, which is powered through a constant inductor 24. By changing the conductivity β of the variable resistance 22 , you can change the time constant of differentiation:

(2)

(2)

- объем емкости 21.where

- container volume 21 .

.The output signal through the nozzle 25 acts on the plate 3 with a jet under pressure proportional to the expression

.

которого равен:Both output channels of the PI controller and the differentiating link are fed to the adder 26 , the output signal

which is equal to:

(3)

(3)

- разность давлений на входе ПИ-регулятора,

- коэффициент усиления,

- коэффициент преобразования.where

- pressure difference at the inlet of the PI controller,

- gain,

- conversion factor.

Formula (3) reflects the PID control law implemented in this invention.

In FIG. 2 shows a diagram of the analysis of the operation of the regulator in a semi-permanent operating mode. In periods A and C, when the controlled variable moves away from the reference, the controller is switched on, and in periods B and D it is switched off.

на отключение регулятора согласно фиг. 2 равен:Signal

to turn off the regulator according to Fig. 2 equals:

, (4)

, (four)

, сигнал ошибки, равный разности давлений переменной и задания,

- сигнал разности производной ошибки (знака скорости), принимающие положительное или отрицательное значения в зависимости от направления касательных прямых к синусоиде изменения переменного параметра

.where

, error signal, equal to the difference between the pressures of the variable and the reference,

- signal of the difference of the derivative of the error (velocity sign), which takes positive or negative values depending on the direction of the tangent lines to the sinusoid of the change of the variable parameter

.

(

- пороговое значение сигнала элемента 27) выдает сигнал

. При отрицательном -

выдается сигнал

.With a positive error sign

(

- the threshold value of the signal element 27 ) gives a signal

. With a negative

a signal is given

.

.To determine the sign of the speed, a differentiating link 2 is used, which determines the rate of change of the variable parameter

.

.The output signal of link 2 is at a time constant

.

, соответствует выходной сигнал порогового элемента 28

, отрицательному -

.positive speed sign

, corresponds to the output signal of the threshold element 28

, negative -

.

служит командой, определяющей условия отключения регулятора с помощью элемента 30, работающему по функции «Запрет». При

, когда знаки ошибки

и ее скорости

не совпадают, то есть

, регулируемая величина приближается к заданному значению. При

, когда знаки

и

совпадают (

), регулируемая величина удаляется от заданного значения.Signal

serves as a command that determines the conditions for turning off the regulator using element 30, which works according to the "Prohibition" function. At

when error signs

and her speed

do not match, that is

, the controlled variable approaches the set value. At

when the signs

and

match up (

), the controlled variable moves away from the setpoint.

и

поступают на вход элемента 29, реализующего функцию неравнозначности по формуле (4), а выход этого элемента

соединен с элементом 30, работающим по функции «Запрет» для отключения сигнала выхода регулятора I. Both discrete signals from two threshold elements27 and28

and

arrive at the input of the element29, which implements the nonequivalence function according to the formula(four), and the output of this element

connected to the elementthirtyworking by function"Ban" to disable the controller output signalI.

Bibliographic data

[1] Dmitriev V.N., Gradetsky V.G. Fundamentals of pneumatic automation. M., "Engineering", 1973. S. 197-199.

[2] Patent of the Russian Federation No. 2680614 05/04/2018. Jet-photocompensation proportional regulator // Application No. 2018116605, 05/04/2018. / Makarov V.A., Korolev F.A., Makarov A.V., Tyutyaev R.E.

Claims (1)

Inkjet-photocompensation semi-permanently operating proportional-integral-differential controller, consisting of a proportional-integral PI controller and a differentiating link, moreover, the PI controller includes inlet nozzles normally located to the sensitive element - a plate, the angle of rotation of which is proportional to the force of the jets and is recorded by an optical part of the regulator, consisting of a light source, a condenser, a diaphragm and a dual photoresistance, which is part of an equilibrium electric bridge, in the feedback of which there is a magnetoelectric galvanometer, a resistance divider for changing the gain, an output milliammeter for recording the output signal and an integral link consisting of an electric capacitor and variable resistance to change the integration time constant, characterized by the fact that the differentiating link consists of pneumatic variable resistance, constant volume, one a membrane accurate follower and a nozzle located normally to the plate of another magnetoelectric galvanometer, the output of which is combined by an adder with a PI controller, at the output of which there is a node for generating a control command to turn off the controller when the controlled value and its speed deviate from the target, made in the form of a trip relay with two parallel located threshold elements, wherein the first threshold element is connected to the output of the controller to determine the sign of the error, and the second threshold element is connected to the differentiating link to determine the sign of the speed.

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