SU531130A1 - Automatic control device - Google Patents

Description

one

The invention relates to automation and can be widely used to build high-precision tracking systems.

Known devices for combinatorial control are known in which, due to the absence of contradictions between the stability and invariance conditions, it is possible to achieve high control accuracy. For the construction of combined control devices, direct measurement of the control action and its performance is required 1

The difficulties associated with the practical implementation of measurement of the derivatives of the control action do not allow us to completely eliminate the dynamic errors in the combined control devices.

Also known are devices with non-unit feedback used to reduce the error caused by control actions in a closed-loop control system 2.,

In devices of this kind, the adjusted magnitude –sha (t) goes to the comparison unit on the main feedback with the transfer function not equal to one, t, e, H (P) / - 1. To obtain full invariance as the transfer function of the main Feedback must have:

vvcp-i)

(ABOUT

F (r)

W (p)

By decomposing this expression in power series we get:

f (r) (+ ...). (2.)

This shows that for complete invariance, it is necessary to use main feedback with a transfer coefficient that is generally different from one: oQ / 1 (in astatic systems, about 1), and additionally introduce positive feedbacks derived from .

The realization of full invariance, i.e. the realization of condition (1), is practically impossible due to the impossibility of the exact introduction of higher derivatives (2), and also due to the fact that

(1) the system will be at the stability boundary.

Of the known automatic control devices, the closest in technical essence is a device comprising a first latch and a first adder, an amplifier and an actuator connected in series, the output of which is connected to the second input of the first adder and tachogenerator input, the output of which is connected to the differentiator and the first input The second adder, the output of which is connected to the first input of the second latch, the second input of which is connected to the pulse generator, and the output to the second input home amplifier 3 Experimental studies of this device have shown that as the frequency of the driver changes, the value of the device error increases. The increase in large errors is caused by the appearance of a shift between the phases of the Ohlibka signal and the correction signal. In other words, due to the non-linearity of the amplitude-frequency characteristics of the differentiating links in this device, a transmission or an undercompensation of the error signal of the corrected system is observed.

The purpose of the invention is to improve the accuracy of the device, regardless of the frequency of the driver.

The goal is achieved by the fact that in the automatic control device a modulator and a series-connected null-organ are installed, the input of which is connected to the output of the tachogenerator, and a sawtooth generator, the output of which is connected to the first input of the first lock, the second input organ, and the output with the control inputs of the modulator and the differentiator, which through the modulator is connected to the second input of the second adder.

The drawing shows a block diagram of the automatic control device.

The device contains the first and second adders 1 and 2, the amplifier 3, the actuator 4, the pulse generator 5, the first and second latches 6 and 7, the tachogenerator 8, the modulator 9, the differentiator 10, the zero-body 11, the sawtooth voltage generator 12.

The device operates as follows. When the frequency of the reference signal changes, the frequency of the signal at the output of the tachogenerator 8 also changes. The nullorgan 11 records the moments of the signal at the output of the tachogenerator 8 through zero in the form of short pulses

rectangular positive polarity, the frequency of which is inversely proportional to the half-period of the setting effect. The leading edge of such a pulse is controlled by memorizing the voltage of the sawtooth generator 12 on the first clamp 6, and the rear zeroing the signal at the output of the sawtooth generator 12 followed by starting it , By the time of occurrence of the next pulse at the output of the zero-body 11, the voltage at the output of the sawtooth voltage generator 12 is proportional to the half-period of the driver impact

5 The process of controlling the memory of the voltage generator of the sawtooth voltage 12 on the first latch 6 and zeroing the signal at the output of the sawtooth voltage generator 12, followed by its start

20 repeats with the arrival of each pulse from the output of the null organ 11. Thus, at the output of the latch 6, a signal is generated that is proportional to the frequency of the driving force. This signal is applied to the control inputs of the modulator 9 and the differentiator 10, the time constant of the differentiator 10, which can be built, for example, on the elements, can be changed by controlling the value of the variable co

30 opposition, which can be used as a varistor. When changing the time constant of the differentiator 10 by changing the value of the variable resistance, the front-to-35 coefficient of the front resistance changes, the transfer coefficient of the differentiator 10 changes. To take into account the change in the transfer coefficient of the differentiator 10, the modulator 9 serves as the transfer coefficient of which

40 when the frequency of the driver, t, e, of the signal at the output of latch 6 is changed. In this device, amplifier 3 performs the functions of adder - amplifier. Second latch 7 controlled by generator

 pulses 5, serves to memorize the value from the output of the second adder 2 to the period following the pulses from the output of the pulse generator 5; the signal from the output of the adder 2 is stored in

50 moment of presence of pulses from the output of the pulse generator 5.

A new positive effect with the use of the proposed device is to significantly improve the accuracy of the system by controlling the phase of the correction signal when the frequency of the driver is changed. Experimental studies have shown that with a change (increase) in the frequency of the gQ of the giver (the initial frequency

Claims (3)

1. Theory of automatic control, part 1, under the general ed. A.V. Natushila, Ed. Higher School, M., 1968 p. 269. M., Higher School, 1968, p. 269. 2. Besekersky V. A. and others. Theories of automatic control systems. W., Science, 1966, p. 249. 3. Kuzin L. T. Calculation and design of discrete control systems. M., Maiugiz, 1962, p. 218-22O.