SU1238025A1 - Pulse regulator - Google Patents

Abstract

The invention relates to the field of heat and power engineering and chemical industry and can be applied in pulse systems of automatic control of objects with filtering means. The aim of the invention is to improve the speed and simplify the controller. In the data controller, the error signal is fed to the inputs of the filter, the first and second relay units and to the information input of the input filter, the output of which is fed to the inputs of the detector and the third relay unit. The output signal of the third relay block is fed to the first input of the pulse-width modulator and through the one-shot to the control input of the input filter. The output signal of the detector through the key is poked to the second input-latitude-pulse modulator, the output signal of which enters the first inputs of the first, second and third elements I. The output signal of the filter goes through the quarter relay unit to the second input of the first element I and from output - pa control input key. The output signals of the first and third relay units are fed to the second inputs of the second and third elements I. The output signals of the second and third elements And, respectively, through the first and second power amplifiers arrive at the corresponding inputs of the actuator. As an input filter, either a controlled integrator or a controlled aperiodic link can be used. .2 3.p.f-ly., 4 ill. (Oh c (Oh her 00 about IND sd

Description

The invention relates to heat engineering and the chemical industry and can be applied in impulse systems for the automatic control of objects with filtering properties.

The purpose of the invention is to increase speed and simplify the controller.

Figure 1 shows the functional diagram of the controller; 2 and 3 are schematic diagrams of embodiments of the input filter; Fig. 4 shows plots of the output voltages of the main blocks of the regulator.

In Figures 1-4, the following designations are accepted: input filter 1, fourth, third, second and first relay blocks 2-5, a pulse width modulator 6, a one-shot 7, a detector 8, a key 9, a filter 10, the third, first and second elements And 11, 12 and 13, the first and second amplifiers 14 and 15 of power, the adder 16, RS-trigger 17, the fifth relay unit 18, the integrator 19, the actuator 20, the executive motor 21, gear 22 , error meter 23, resistors 24 and 25, capacitor 26, operational amplifier 27, switch 28, Uj, input pulse voltage ra (i.e. mismatch voltage) output voltage of input filter 1, U, j - output voltage of four; that relay block 2, Uj - output voltage of one-oscillator 7, output voltage of pulse-width modulator 6 , Uj- the output voltage of the detector 8, the output voltage of the switch 9, the output voltage of the filter 10, Ug- the output voltage of the third relay unit 3, the output voltage of the third element And 11, and, C, the output voltages

 10 11

respectively the second and first relay units. 4 and 3, C, and the output voltages of the first and second elements, respectively, And 12 and 13, Ug, x output signal of the actuator 20. I. ..

The pulse width modulator 6 contains an adder 16, a trigger 17, a fifth relay unit 18, and an integrator 19. A known RS trigger can be used as a trigger 17.

As an actuator 20 in this case, a constant speed actuator is used, which contains (single-phase

to

15 j

380252

motor) 21 and (power) gear 22.

As an input filter 1, one of the variants 5 of the input filter configuration shown in Figures 2 and 3 can be applied. The first embodiment of the input filter is a controllable integrator and contains a resistor 24, a capacitor 26, an operational amplifier 27 and key 28. The second embodiment of the input filter is an aperiodic link and contains resistors 24 and 25, a capacitor 26, an operational amplifier 27 and a key 28. In addition, the specified periodic link can be implemented in any known manner.

The filter 10 performs in this controller the function of the DC selection block of the error signal. As the filter 10 can be used any limestone lowpass filter. As the detector 8 can be used any known push-pull detector.

The regulator works as follows.

 A voltage proportional to the difference between the set and actual values of the controlled parameter is applied to the regulator input. The voltage U is supplied simultaneously to the signal input of the input filter 1, to the inputs of the second and first relay blocks 4 and 5, fixing the sign of the error voltage Ug ,, and to the input of the detector 10. The block diagram of this controller allows operation in three modes depending on the size of the dead zone of the third relay unit 3, which in the indicated example of implementation of the regulator has a three-position characteristic. If the dead zone of the third relay unit is equal to zero, then this controller operates in the frequency-pulse modulation mode, in which the outputs of the first and second And 12 and 13 elements generate pulsed voltages and U, j, whose pulses have a constant duration and the following frequency, determined by the magnitude of the misalignment voltage U. In this case

tea at any voltage value and at the output of the filter 10 at the output of the third relay block 3 there is

non-zero voltage Ug, which is applied to the second (inverse) input of the third element 11 and prevents the appearance of a voltage different from zero voltage Ug that ensures the closure of the key 9, i.e. switching on the circuits of control voltage pulse duration adjustment.

With increasing voltage U, the output of the input filter 1 is sufficient for triggering the fourth relay unit 2, the voltage Uj arrives at the clock input of the pulse width modulator 6 at its output. A trigger 17 is switched and at the output of the pulse-width modulator 6, a voltage U appears at the second inputs of the first and second elements AND 12 and 13. Depending on the polarity of the error voltage Ug, the voltage U (or U, j ) at the output of the element And 12 (or 13), which is determined respectively, the presence of a voltage (or C ,,) at the output of the relay block jca 4 (or 5). When voltage V appears at the output of the fourth relay block 2, the single vibrator 7 is triggered on the leading edge of the voltage and. At the output of the single vibrator 7, a short voltage pulse occurs and arrives at the control input of the input filter 1 and causes its zeroing. Subsequently, the voltage U at the input of the pulse-width modulator 6 disappears, since the voltage U is fed through the adder 16 to the input of the integrator .19 and when its output voltage reaches a value sufficient to operate the fifth relay unit 18, the reverse switching of the trigger 17 occurs and the return of the pulse-width modulator 6 to the initial state. When the error voltage is kept at the input of the regulator, the control process is repeated and at the output of the power amplifiers 14 and 15 rectangular pulses of control voltage of a constant duration are generated,

If the dead zone of the Third Relay Unit 3 is not zero, the controller provides an additional modulation of the control pulses for the duration of the control unit. The greatest effect from the application of this regulator is provided in av

oscillatory systems of automatic control by an object that has filtering properties. In this case, the dead zone size of the third relay unit 3 is selected so as to exclude the closure of the key 9, i.e. eliminate the possibility of regulator correction circuits operating in a transitional mode of operation, when the regulator controls a disturbing or disturbing effect until a self-oscillating operating mode of the regulator, characterized by alternating occurrence of control voltage pulses at the outputs of the first and second elements And 12, occurs and 13.

When, as a result of testing by an external regulator, the constant component of the error voltage and reaches a predetermined value (for example, time t, Fig. 2), then the voltage U at the output of the third relay unit 3 disappears. When the output of the pulse-width modulator 6 front. the front of the next voltage pulse U; the switch closes 9 | and the voltage I- from the output of the detector 8 goes to the control input of the pulse-width modulator 6 and, accordingly, to the second input of the adder 16. At the same time, the duration of the voltage pulses U U and U. .

If in the control system in which this regulator is used, a symmetric self-oscillating mode of operation is provided, characterized in that the oscillation axis of the output signal U, the regulator is at the same distance from the value of the signal Ugj, when there is no voltage pulse U, and at the outputs of the first and second elements And 12 and 13, then at the output of the regulator, the pulses of the signal U, have a constant duration. This is due to the fact that a symmetric self-oscillating signal at the output of the actuator 20 in a modulation controller of this class corresponds to a symmetrical voltage variation at the output of the input filter 1. In this signal for different polarities of the error voltage Ug, the pulse duration the output signal 11 ,, of the regulator increases as a result of the effect of the correction voltage Ug on the same value. If, due to the corresponding initial conditions in the controller, an asymmetrical self-oscillatory output signal Vgbtx or an asymmetrical self-oscillation oscillator output signal Ug occurred due to external disturbance (for example, time t, fig 2), then the voltage also changes at the output input filter 1. In this case, the control voltage pulse duration and C at the outputs of the first and second elements I 12 and 13 are corrected until a symmetric auto-oscillation is set at the output of the regulator ny signal U,

howled in case as input

filter 1 uses the first known implementation of the input filter (see Fig. 2), by ensuring the symmetry of the output signal of the controller, the accuracy of the controller is improved, since it reduces the deviation of the regulating parameter from its predetermined value.

If the second known embodiment of the input filter is used as the input filter t (see Fig. 3), the speed of the controller is significantly increased. This is due to the fact that when using the second variant of the input filter in the self-oscillatory mode of the regulator, the magnitude of the constant component of its output signal and ..., depends only on its degree

asymmetry and is zero when the symmetric

control output Ugb, x. In this case, replacing the first variant of the input filter with the second variant significantly improves the dynamic characteristics of the controller, Improving the speed of this controller is ensured by the fact that, unlike the prototype controller, the correction of the output signal of the Uee, y controller provides asymmetry and constant, while in the prototype the specified correction is provided only when the third impulse of the control voltage appears relative to the moment of the beginning of the asymmetries The output of the regulator prototype signal. .

0

five

0

five

 .

If necessary, in this controller, a mode of operation with constant frequency-width modulation of the control voltage can be provided. In this case, the magnitude of the dead zone of the third relay unit 3 is set larger than the maximum possible value of the constant component voltage error Ug. . Thus, in this controller, it is possible to create an internal loop regulating the initial conditions, ensuring the elimination of a constant component of the error (i.e., static error) of the regulator during the operation of the controller in the auto-oscillatory mode, allowing, if necessary, to provide a frequency-width modulus control voltages and possessing simplicity of technical realization in comparison with known pulse controllers.

Claims (3)

1. A pulse controller containing the first and second relay blocks, whose inputs are interconnected, and the inputs are connected to the first inputs of the first and second And elements, respectively, the second inputs of which are interconnected by the first and second power amplifiers connected by outputs to the first and the second inputs of the actuator, an input filter connected by a CIUM input via a filter to the input of a third relay unit, a control input to the one-vibrator output, and an output through a quarter-relay unit to a clock input ohm pulse width modulator, control input connected to the output of the key connected to the control input with the output of the third element I, which is used to increase the speed and simplify the controller, in him; additionally installed a detector connected to the output with; a keynote input, and an input to the output of the input filter connected by a signal input to the input of the first relay unit; the output of the fourth relay unit connected to the input of the one-vibrator; the output of the pulse-width modulator connected to the second input of the first element Inc first entry 7 the third element And connected by the second input to the third relay unit, the outputs of the first and second elements And connected to the inputs, respectively, of the first and second power amplifiers. 2 .. Controller pop. 1, which differs from the fact that the pulse-width modulator contains a series-connected RS flip-flop, an adder, an integrator and a relay element connected to the R input of the RS flip-flop, connected by an S-input with a clock input of a pulse-frequency modulator, an inverse output - with a control input of an integrator, a direct output - with an output of a pulse-width123 12380258 modulator connected by a control input to the second INPUT of the adder. 3. Regulator tor on PP. 1 and 2, that the input filter contains an operational amplifier connected by an input to the first capacitor plate and the first terminals of the first and second resistors and, and an output to the second capacitor plate, the second terminals of the second resistor and switch, and the output input filter, the input connected to the second output of the first resistor, and the control input - with the control input of the key. vm23 Js UL fe Vs. ; U-, 4gM-HL-HZ t ft Compiled by Yu Gladkov Editor M. Dylyi Tehred O. Gortvay Corrector T. Kolb Order 3289/47 Circulation 836 Subscription VNII1Sh State Committee of the USSR for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., d. A / 5 Production and printing company, Uzhgorod, Projecto st., A