SU1170426A1 - Pulse regulator - Google Patents

Abstract

PULSE REGULATOR containing the error meter, differentiator, adder, first and second one-shot, first OR element, first relay block, first and second keys, first integrator, second relay block connected in series and second OR element, second integrator connected by a control input to the output of the third one-shot, and the output - to the input of the third relay unit, the fourth relay unit connected by the outputs with the first inputs of the first and second elements, respectively, And, the first and second Wuxi Power connectors connected to the outputs of the first and second inputs of the actuator, respectively, characterized in that, in order to increase the speed of the wines and the static accuracy of the regulator, it additionally establishes sources of the reference and correction signals and a fourth one-vibrator connected by the input to the output of the second relay unit and output - from the control input of the first integrator, connected by an output to the input of the second relay unit, and input through a differentiator - to the output of an adder, connected to the primary input with the output of the reference signal source, the second input with the output of the correction signal source, and the third input with the output of the error meter, with the input of the fourth relay unit, with the signal input of the second integrator and with the input of the first relay unit, output connected to the control the inputs of the first and second keys connected by signal inputs (L to the output of the third relay unit and to the input of the third one-oscillator; the output of the second switch is connected to the second input of the second element OR, connected th output via first monostable multivibrator to the first input of the first OR gate coupled to the second input via a second monostable multivibrator with an output of the first key, and the output - to the second inputs of the first and second elements and outputs connected to the inputs of respective power amplifiers. 4 to O5

Description

The invention relates to pulsed means of automatic control and can be used as a proportional-integral controller in control systems of iron-cutting machines.

The aim of the invention is to increase the speed and static accuracy of the controller.

FIG. 1 shows a functional diagram of the controller; in fig. 2 is a block diagram of a control system with this controller; in fig. 3 - impulse response of the actuator.

The diagram shows the second and first integrators 1 and 2, the third, first, second, fourth relay blocks 3, 4, 5, 6, the first and second keys 7 and 8, the second, third, first and fourth one-shot 9, 10, 11, 12, first and second elements OR 13, 14, first and second elements AND 15, 16, first and second power amplifiers 17, 18, adder 19, error meter 20, differentiator 21, reference signal source 22, unit 23, actuator 24 , the source of the correction signal 25, the sensor of the adjustable parameter 26, the object 27, the first and second frequency-impulse mo Str tori 28 and 29, first and second non-linear elements 30 and 31, first and second conditioners rectangular pulses 32 and 33, actuators 34 and 35, an adder 36, integrators 37 and 38, Us - signal specifying, UK - the correction signal. Up is the regulating parameter, y is the pulse duration, Zek is average equivalent to the rotation speed of the actuator 24 shaft, So is the nominal rotation speed of the actuator 24 shaft.

The structure of the first frequency-pulse modulator 28 functionally includes the second integrator 1, the third relay unit 3 and the third one-oscillator 10, and structurally the integrator 37, the non-linear element 30 and the square pulse shaper 32

The composition of the second frequency-pulse modulator 29 functionally includes the first integrator 2, the second relay unit 5 and the fourth one-shot 13, and the structural integrator 38, the nonlinear element 31 and the square pulse shaper 33.

As an actuator 24 in this controller, a constant speed actuator is used, this actuator is depicted in the functional diagram of the regulator (Fig. 1) as one functional unit 24, and in the block diagram of the regulator (Fig. 2 ) - in the form of three structural blocks: actuators 34, 35 and adder 36.

The regulator works as follows.

One of the inputs of the error meter 20 receives a signal Up from the output

sensor adjustable parameter 26, to another input which receives a signal Us from the output of the setter 23. The output of the error meter 20 generates a error signal, which is fed to the signal input of the second integrator 1, to the third input of the adder 19 and to the inputs of the first and fourth relay blocks 4 and 6.. The error signal is integrated in the second integrator 1 and is fed to the input of the third relay unit 3. When the output signal of the second integrator 1 reaches a value greater than the dead zone of the third relay unit 3, the latter triggers and generates a pulse signal which, with its leading edge, triggers the third single-oscillator 10 and depending on the state of the keys 7 and 8 of the second or the first one-shot 9 and 11. The choice of the running one-shot 9 (or 11) depends on

Q is from the absolute value of the error signal. In the event that the error signal does not exceed the magnitude of the dead zone of the first relay unit 4, then there is no signal at its output and the first key 7 is in the closed

5 states. The output signal of the third relay unit 3 through the closed first key 7 is fed to the input of the second one-shot 9, which operates on the leading edge of its input signal. The pulse duration at the output of the third one-vibrator 10 is set as low as possible due to the full discharge of the second integrator 1 when the one-shot 10 is triggered, and the pulse duration at the output of the second one-shot 9 is determined, based on the requirement to ensure the specified value of the adjustable parameter.

Depending on the polarity of the error signal, the output pulse signal of the second one-shot 9 through the first element OR 13 is fed to the desired excitation winding of the actuating mechanism 24, which acts on the object 27 in such a way as to reduce the error signal. The selection of the excitation winding of the actuator 24 is determined by the output signal of the fourth relay unit 6. For example, if the error signal is positive, then the direct output of the fourth relay unit is present

0 output signal, and at its inverse output is absent. In this case, the pulse output signal of the first element OR 13 is fed to the second inputs of the first and second elements And 15, 16, and the signal at the direct output of the fourth relay block 6

5 is fed to the first input of the first element And 15 and allows the passage of the output signal of the first element OR 13 through the first element And 15 and the amplifier

power 17 to the first input (to the corresponding excitation winding) of the actuator 24. Since the control signal pulse in the regulator control channel in question is formed each time the integral of the error signal changes by a fixed amount equal to the dead zone of the third relay unit 3, and a change in the input (excitation winding number) of the actuator 24 upon a change in the polarity of the error signal is equivalent to a change in the polarity of the output signal the controller in the structural representation of the actuator 24 in two parallel-connected integrating mechanisms 34, 35 connected by outputs to the inputs of the adder 36, the integral control channel of this controller discussed above can be structurally represented as a serial connection of the integrator 37, a nonlinear element 30 of the type "quantizer increments and square ripper 34 pulses with transfer function

-eW (p, l where Y is the duration of the control signal pulse (Fig. 2). A series connection of the rectangular pulse generator 30 with the above-mentioned transfer function and the integrating actuator 34 having the transfer function

W 1-eW / B1 - -IT,

IP

arp

can be replaced by a pure delay structural unit having a transfer function

W ,,, e-i.

Thus, the operation of the integral elements of the integral control channel of the regulator described above forms the controlling effect on the object 27 according to the integral control law with an approximation error determined by the presence in the control channel of the structural element - rectangular impulse drivers 30.

In addition, during the operation of the regulator, the output signal (i.e., the error signal) of the error meter 20 is fed to the third input of the adder 19, the first and second inputs of which receive the output signals of the corrective and reference sources. The output signal of the adder 19 through the differentiator 21 is fed to the input of the frequency-pulse modulator consisting of the first integrator 2, the second relay element 5 and the fourth one-oscillator 12. Due to the presence in the regulator of the differentiator 21, a set of blocks,

The second relay element 5, the fourth one-shot 12, the second element-OR 14, and the first one-shot 11, forms a proportional component of the control law and is a proportional control channel for the controller.

In general, this controller provides the formation of a proportional integral law (PI law) of regulation when controlling the constant speed actuating mechanism 24 without using internal feedbacks that significantly limit the region of stability of the controller. Changing the pulse width of the control signal of the integral channel of regulating the regulator by switching the first and second keys 7, 8, depending on the magnitude of the error signal, ensures the highest quality adjustment process in the regulator.

The dynamic properties of the constant speed actuator 24 are characterized by its impulse response — the ratio of the equivalent speed 5 eq of displacement of the actuator 24 shaft to the nominal sound of the control signal impulse duration

f (v)%:

(one)

where the average equivalent rate is 5 eq.

5 eq (tvkl -) - tvyb) / y, (2)

where Shvkk.1 is the movement of the actuator shaft during the time of action of the control signal, and the movement of the shaft of the actuator during the run-down time.

The typical experimental impulse response of the constant speed actuator 24 is shown in FIG. 3. Due to the substantial non-linearity of the characteristic of the actuator 24, when the width and width-frequency modulation of the control signal is in the process of adjustment, there is a constant change in the equivalent system gain factor. We use this regulator (Fig. 2), since transfer of the actuator 24 is determined by its response to a single pulse of the control signal in that it is identical to the equivalent speed of movement of the shaft of the actuator 24 for a given duration of the pulse control signal. Since in this controller that implements the PI-law of regulation, the duration of the control signal pulses is constant, the nonlinearity of the impulse response of the actuator 23 does not adversely affect the control process in the controller. The shorter the pulse duration of the control signal of the regulator, the better the dynamic characteristics of the control system in which it is used, since less is the equivalent of the structural component of the pure delay, which characterizes the finite pulse width of the control signal of the regulator. On the other hand, the minimum value of the pulse duration, for example, 72 (Fig. 3) does not provide the maximum accuracy of the above system in steady state. The static accuracy of the system in which this controller is used, when using a constant speed actuator 24, can be characterized by

Oeq / o

, (3)

the minimum possible value for which for this type of actuator 24 determines the minimum possible sampling rate of the output coordinate of the control system in which this controller is used. For the dependency shown in FIG. 3, which is provided at .3 C. A further decrease in the pulse duration of the control signal of the regulator leads to an increase in n in connection with the non-linearity of the characteristic of the actuator 24. Therefore, it is advisable to use the shortest pulse width when working on the disturbing or controlling effect at large values of the error signal, and such a duration of the control signal pulse, which provides the greatest accuracy of the integral control channel controller with small values of the error signal. Providing such an algorithm for selecting the pulse width of the control signal of the regulator is ensured by the presence in the controller of the first relay unit 4 and the first and second keys 7 and 8. In the case when the error signal is small, the signal at the output of the first relay unit 4 is absent the key 7 is closed and when the third relay unit 3 is triggered, the second one-shot 9 starts, the pulse duration at the output

which is selected from the condition of the greatest accuracy of the control system with this controller. Thus, the structure of this controller provides the strongest static accuracy of the control system with the best dynamic characteristics of the system, determining its speed. The structure of this controller also provides the possibility of introducing corrective actions into the proportional regulating channel of the regulator. The input of corrective actions is provided by the source of the correction signal 25 and the adder 19. When the value of the correction signal deviates from the value of the reference signal generated at the output of the source of the reference signal 22, it is proportional to The regulator channel controls the formation of the corresponding number of pulses of the control signal. For example, when using this controller in temperature control systems containing heat exchangers, a signal proportional to the temperature of the heated coolant at the entrance to the heat exchanger, the flow rate of the coolant, etc. can be used as a correction signal.

An analysis of the operation of this regulator made it possible to establish that its distinctive features indicated above make it possible to increase the regulator's speed by about

 20-30% and its static accuracy by 15-20% compared with the prototype. In addition, in the regulator, the switching frequency of the actuator 24 is reduced approximately 5-fold, thereby increasing the reliability of the regulator. The above improvement in the quality of regulating the regulator is explained by the absence of internal control loops, the optimal choice of the duration of the control pulses, the elimination of the nonlinearity of the characteristics of the actuator 24 on the regulating process, and the fact that the input element of the regulator The torus is a second integrator 1 that provides almost complete interference damping without increasing the insensitivity zone of the controller.

2IP

N -0

;

fcij

M-5

t0 .1., 4 55 0.6 OL 0.8 0.8 Od 10 1

and Phage.Z

1.2 13 seconds

Claims (1)

A PULSE REGULATOR containing a mismatch meter, a differentiator, an adder, a first and second one-shot, a first OR element, a first relay block, a first and a second switch, a first integrator, a second relay block and a second OR element connected in series, a second integrator connected to the control input with an output the third one-shot, and the output with the input of the third relay block, the fourth relay block connected by the outputs to the first inputs, respectively, of the first and second elements And, the first and second amplifiers power connected by the outputs respectively to the first and second inputs of the actuator, characterized in that, in order to increase the speed and static accuracy of the controller, it additionally has sources of reference and correction signals and a fourth one-shot connected to the input with the output of the second relay block, and the output - with the control input of the first integrator, connected by the output to the input of the second relay block, and the input through the differentiator - to the output of the adder connected to the first input with the output of the reference signal source, the second input - to the output source of the correction signal and the third input - to the output meter error, to the input of the fourth relay unit, the signal input of the second integrator and to the input of the first relay unit output connected to the input yn _l ravlyaetsya the first and second § keys connected by the signal inputs to the output of the third relay block and to the input of the third one-shot, the output of the second key is connected to the second input of the second OR element connected to the output Without the first one-shot to the first input of the first OR element connected to the second input through the second one-shot with the output of the first key, and the output to the second inputs of the first and second AND connected to the outputs of the inputs of the respective power amplifiers. SU „„ 1170426>