RU2773115C1 - Jet-pneumatic semi-proportional regulator - Google Patents

Abstract

FIELD: automatic systems.

SUBSTANCE: invention relates to the field of automatic control systems, in particular to pneumatic automatic regulators. The device consists of a proportional regulator and a node for forming a control command to turn off the regulator when the controlled value and its speed deviate from the task. The output of the jet-pneumatic proportional regulator is connected via a disconnecting relay with two parallel jet-pneumatic threshold elements. In this case, the first threshold element includes nozzles located opposite to the sensitive element (the plate) connected to the output of the regulator and to the threshold element of the error sign, and the second threshold element contains nozzles connected to the speed sign detection unit.

EFFECT: increase in the speed of regulation by using a compensation scheme in a semi-proportional regulator based on the force action of the jet on a movable barrier.

1 cl, 1 dwg

Description

The invention relates to the field of pneumatic automatic regulators.

A pneumatic semi-proportional controller is known from the prior art, the principle of operation of which is based on the use of a control action depending on the sign of the error, equal to the difference between the value of the controlled parameter and its reference, as well as on the rate of change of this error [1]. A semi-proportional controller consists of a proportional controller, a delay unit for a cycle, and a unit for generating a control command to turn off the regulator. The proportional controller includes a comparison element, in the feedback of which there is a divider consisting of variable and constant chokes, the change in the conductance ratio of which leads to a change in the gain of the input pressure difference. The node for generating the control command to turn off the controller when the controlled value and its speed deviate from the reference consists of comparison elements and a preliminary node that implement the control action depending on the magnitude and sign of the error signal and its derivative. All components of the prototype are made of membrane elements of the USEPPA universal system.

The disadvantage of such a semi-proportional regulator is the low dynamic properties inherent in membrane elements,

The technical result achieved in the present invention is to increase the speed of regulation through the use of a compensation scheme in a semi-proportional regulator based on the force action of the jet on a moving barrier.

The prototype closest to the proposed solution in technical essence is a proportional regulator, 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 "reading nozzle-shutter" type assembly, a pneumatic membrane power amplifier , while the movable part is a plate rigidly connected to two nozzles of the gas support, and the reading element is covered by two nozzles located before and after the pneumatic membrane power amplifier, which forms a regenerative feedback with a gain greater than one. An increase in sensitivity and speed is provided through the use of a measuring compensation circuit for the force action of the jet on a moving barrier and registration of this effect using a pneumatic compensation circuit [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 operation of the regulator in a semi-permanent mode.

More specifically, the technical result is achieved by the fact that the jet-pneumatic semi-proportional controller consists of a proportional controller, a node for generating a control command to turn off the controller when the controlled value and its speed deviate from the target, characterized in that the output of the jet-pneumatic proportional controller is connected through a trip relay with two parallel jet-pneumatic comparison elements, the first comparison element includes nozzles located opposite to the sensitive element - the plate, connected to the regulator output and to the threshold element of the error sign, and the second comparison element contains nozzles connected to the preliminary block and the threshold element for determining the speed sign.

на отключение регулятора при отклонении регулируемой величины и ее скорости от задания. Все блоки регулятора представляют собой струйно-пневматические устройства одинаковой конструкции чувствительных элементов, мембранных усилителей и обратных связей. В пропорциональный регулятор 1 и в узел 2 входят: чувствительный элемент - пластина 3, подвешенная на газовой опоре 4. Входной узел регулятора 5 представлен соплами 6 и 7, находящихся под давлением

переменного параметра и

давлением задания соответственно. Для регистрации угла поворота пластины под действием струй предусмотрен считывающий узел, выполненный в виде сопла 8 и заслонки 9, жестко закрепленной на пластине 4. Между соплом 8 и питающим дросселем 10 расположена междроссельная камера 11, связанная с входом усилителя мощности 12. Выход усилителя 12 связан с входом элемента 13, реализующего функцию «Запрет» и управляемым командой

от элемента 30, и с соплом обратной связи 14. Для смещения нулевой точки регулятора используется сопло 15, находящееся под давлением

. Для компенсации силового действия струи, исходящей из сопла 8, предусмотрено компенсационное сопло 16, соединенное с междроссельной камерой 11. Сопло 8 совместно с усилителем 12 и соплом обратной связи 14 образует регенеративную обратную связь, которая придает стабильное исходное положение подвижной системе. Figure 1 shows a diagram of a jet-pneumatic semi-proportional controller, consisting of a proportional controller 1 and node 2 for generating a control command

to turn off the controller when the controlled value and its speed deviate from the reference. All regulator blocks are jet-pneumatic devices of the same design of sensitive elements, membrane amplifiers and feedbacks. The proportional regulator 1 and the assembly 2 include: a sensitive element - a plate 3 suspended on a gas support 4 . The input node of the regulator 5 is represented by nozzles 6 and 7, which are under pressure

variable parameter and

task pressure respectively. To register the angle of rotation of the plate under the action of the jets, a reading unit is provided, made in the form of a nozzle 8 and a damper 9 rigidly fixed on the plate 4 . Between the nozzle 8 and the supply throttle 10 there is an interthrottle chamber 11 connected to the input of the power amplifier 12 . The output of the amplifier 12 is connected to the input of the element 13 that implements the "Prohibition" function and is controlled by the command

from element 30, and with feedback nozzle 14 . To shift the zero point of the regulator, a nozzle 15 is used, which is under pressure

. To compensate for the forceful action of the jet emanating from the nozzle 8 , a compensation nozzle 16 is provided, connected to the interthrottle chamber 11 . Nozzle 8 , together with amplifier 12 and feedback nozzle 14 , forms a regenerative feedback that gives a stable initial position to the moving system.

пропорционального регулятора 1 достигается путем вращения винта 17 и последующим изменением соотношения плеч

и

, определяющих расстояния от осей симметрии газовой опоры 4 до входных сопел 6 и 7, и от газовой опоры 4 до оси симметрии заслонки 9 соответственно.Gain change

proportional regulatorone achieved by turning the screw17and subsequent change in the ratio of the shoulders

and

, which determine the distances from the axes of symmetry of the gas supportfour to inlet nozzles6 and7, and from the gas supportfour to damper symmetry axis9 respectively.

равен:Proportional controller output

equals:

на отключение регулятора при отклонении регулируемой величины и ее скорости от задания, и состоят из двух пороговых элементов 18, 19 и одного блока предварения 20. Node 2 forms a control command

to turn off the controller when the controlled value and its speed deviate from the setpoint, and consist of two threshold elements 18, 19 and one preliminary block 20 .

и выходным давлением регулятора

. При положительном знаке ошибки

выходной сигнал порогового элемента 18 выдает сигнал

. При отрицательном -

- выдается сигнал

. threshold elementeighteen determines the sign of the error between the reference pressure

and outlet pressure of the regulator

. With a positive error sign

threshold element outputeighteen gives a signal

. With a negative

- a signal is given

.

, а выход блока предварения 20 равен: Preblocktwenty includes an integral link consisting of a variable resistance21, which sets the lead time constant, the constant volume capacitance22, precise expendable repeater23 and outlet nozzle24, located normal to the platefour. Expendable Repeater Power23 carried out through a constant choke25. inlet nozzle26 preblock connected to the output of the regulator

, and the output of the prefix blocktwenty equals:

- постоянная времени блока предварения 20;

- объем емкости 22;

- проводимость переменного сопротивления 21. where

- preblock time constanttwenty;

- container volume22;

- conductivity variable resistance21.

через сопло 28 и сигнал выхода регулятора

для его сокращения через сопло 29. The output channel of the pre-block 20 is connected to the nozzle 27 of the threshold element 19 , which also receives a signal

through nozzle 28 and regulator output signal

to reduce it through the nozzle 29 .

, отрицательному -

.The positive sign of the speed corresponds to the output signal of the threshold element 19

, negative -

.

и

поступают на вход элемента 30, реализующего функцию равнозначности:Both discrete signals from two threshold elements

and

arrive at the input of the elementthirty, which implements the equivalence function:

служит командой, определяющей условия отключения регулятора с помощью элемента 26, 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 26, 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 (

), the controlled variable moves away from the setpoint.

[1] Berends T.K., Efremova T.K., Tagaevskaya A.A., Yuditsky S.A. Elements and diagrams of pneumatic automation. M., Mashinostroenie, 1976. S.144-146.

[2] Patent of the Russian Federation No. 2018116604, 05/04/2018. Jet-pneumatic proportional regulator // Patent of Russia No. 2676362, 12/28/2018. Bull. No. 1. / Makarov V.A., Korolev F.A., Tyutyaev R.E., Makarov A.V.

Claims (1)

A jet-pneumatic semi-proportional controller consists of a proportional controller and a unit for generating a control command to turn off the controller when the controlled value and its speed deviate from the setpoint, characterized in that the output of the jet-pneumatic proportional controller is connected through a shutdown relay to two parallel jet-pneumatic threshold elements , wherein the first threshold element includes nozzles located opposite to the sensing element - plate - connected to the controller output and to the error sign threshold element, and the second threshold element contains nozzles connected to the preliminary block and the speed sign detection threshold element.

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