SU656022A1 - Pneumatic adaptive regulator - Google Patents

Description

The invention relates to the field of automation equipment, namely to pneumatic self-adjusting controllers with a reference model and can be applied in local automatic control systems for non-stationary objects with a delay in the petrochemical, oil refining and other industries. The closest technical solution to this is the pneumatic adaptive regulator containing the first element of comparison, the chambers of which are connected to the channels of the parameter, the reference and the reference pressure, and the output through the reference model to the positive chamber of the second element of the comparison, the minus chamber of which is connected to the channel parameter, the regulating unit, the input channels of which are connected to the channels of the parameter, the reference and the reference pressure, and the output channel through the power amplifier with the output channel of the regulator, and the adaptation unit 1. The disadvantage of the known controller is that the lag time of the control object is not taken into account in the adaptation block, which leads to a decrease in the stability region of the self-tuning process when regulating non-stationary objects with delay, the purpose of the invention is to expand the stability region of the controller when adjusting non-stationary objects with delay . This is achieved by TeMt that, in the controller, the adaptation unit contains an adder, an OR element, a reference element, a setpoint controller, a lag node, a relay, an integrator and a valve whose control chamber is connected to the output of the adder, the input of which is connected to the outputs of the settingter, the first comparison element the OR element and the reference pressure channel, the output of the second reference element is connected to the inputs of the delay unit connected by an output through a relay to the integrator input channel, the choke and the capacitance of which are connected through the flow chamber of the valve, the integrator output is connected to the regulating unit, and the control relays cameras to the output of the comparison element of the adaptation unit associated with the reference pressure channel and the output of the first comparison element,. The drawing shows the principle on the scheme proposed by the controller ..

The regulator contains the first element of comparison 1, the reference model containing variable chokes 2.3, capacitance 4.5, element of comparison 6, the second element of comparison 7 regulating the block containing the element of comparison 8 controlled choke 9 element multiplying by a constant factor 10 , power amplifier 11, an adaptation unit containing an OR 12 element, an adder 13, a setting device 14, a comparison element 15, a lag node, including a variable choke 16, a capacitance .17, a comparison element 18,; a relay 19/20 / integrator, including a comparison element 21, variable dross s 22, the container 23, valve 24.

The regulator is built on standard elements of industrial pneumatic automation.

The regulator works as follows:

Comparison element 1 is supplied with pressure, proportional to the value of the parameter: P - to the set point and RP to the current (variable) and; pressure - Pd. At the output of the element 1 we have the pressure ,, equal to

Рвых1 РХ + РО РХ «РП-РЗ-С element 1 pressure Pgbj. passes through the reference model, which includes the delay unit {2,4,6} and aperiodic link (3.5), and enters the positive chamber of the second element of comparison 7. On the second element of comparison 7, pressure ff is compared with the output signal of the reference model, and the resulting mismatch Pg is fed to the lag node of the adaptation unit. The reference model. Realizes the function in the form of e

P / l --- (

M r or

with the help of elements 2,3,4,5,6, and at the output of the element of comparison 7 we have pressure in the form

MOUTH 7% + RO RPD, RVY, passes a delayed node assembled on elements 16, 17,18 and with PQ through relay 19,20 will come depending on P bixts plus and minus chambers h) Reference control integrator 21. formed in reference element 15 as

G1 at

FEET

 IQ with PX +.

Regulating the Reg-Regulator Controller clears the following control algorithm

EARS about e-pt

K- PpSi & nV,

with e g

„ГИ и at P, t О, where sign РХ“. „Р / о.

Kg is the adaptive gain factor (regulation);

PX - mismatch signal. The integrator implements the following expression: pp

 V о с S4D П tu OOIX i rp 4-3 t о л

P

A valve is connected between the tank and the variable throttle of the integrator, which is controlled by means of coded pressure P ,, m "13 from the output of the adder 13.

Elements of comparison 1 and 8 are included according to the pressure summation scheme P ,, РЗ and РО, and the element OR is activated according to the scheme of selection of the maximum signal. The output of the element OR .12 is the error module of the system Pgj ,, x, j, / РХ / РО which goes to the minus camera element of comparison 13.

If we consider Z then

. R .. „.. R in

.0 with / PX /. R,

OUT.1E

at

where PQ is the dead zone, which is set using the setting device 14. If PQ, the valve opens the return and the pressure in the control chamber of the controlled throttle remains unchanged (freezes) until the output changes

RA "i / Pv /, then the valve has a reverse inverse 0 e

depending on the change in P) (the output of the integral changes, which in turn is caused by the pressure from the integrator to the control chamber of the controlled throttle.

A change in this pressure leads to a change in the gain factor Kc of the regulator.

The algorithm for tuning is found using the method of the Lunow function, which guarantees the stability of the adaptation process of the controller gain in the full range of changes in the parameters of the controlled object with delay.

Claims (1)

1. Adaptive pneumatic regulator for regulating the hydrodynamic pressure of the adsorption column (Fig. 2.3), Development of the theory, methods and means of adaptive control of technological processes, p. 9, 12-14. Ministry of Instrumentation, Automation and Control Systems, Scientific and Technical Council, Information and Control Systems Section, Moscow, 1975.