SU1267355A1 - Servo system - Google Patents

Abstract

The invention relates to automatic control systems and can be used in systems where, along with sharp tracking, there is a mode of program installation on a given coordinate or mode of entry into the tracking zone. The aim of the invention is to improve the quality of control, in particular speed, during the processing of large discrepancies. The tracking system contains three adders, a correction link, two amplifiers, a motor, a control object, error and speed sensors, a key, a switching unit and a control unit that contains a quad, a peak, an adder and a relay element with a dead zone. The essence of the invention is to control by means of the control unit i the value of the ratio of the error of the regulation (L and the square of the velocity of the object and the development of the correction relay control signal to the correction link.

Description

The invention relates to automatic control systems and can be used in the class of automatic control systems, in which, along with the tracking mode, one of the main operating modes is also a program setting mode at a given coordinate, or an input mode to the tracking zone.

The aim of the invention is to improve the quality of control, in particular speed when processing large mismatches.

In FIG. 1 is a block diagram of a servo system; in FIG. 2 - an example of the practical implementation of the corrective link and the switching unit.

The tracking system comprises a first adder 1, a corrective link 2, a second adder 3, a first amplifier 4, an engine 5, a control object 6, a position sensor 7, a speed sensor 8, a key 9, a switching unit 10 consisting of η analog keys 10 ^. 10 _h , control unit 11, module allocation unit 12, third adder 13, quadrator 14, second amplifier 15, relay element 16 with deadband.

Corrective link 2 (figure 2) contains capacitors 17 and 18 and resistors 19 and 20.

The switching unit 10 contains analog keys 10-, and 10 ^.

Denote b is the error signal of the tracking system at the output of the first 1 adder.

At the output of control unit 11, a logical signal is generated .5

0, for / 0 / + δ? to co ²

1, for / b / + δ <kω ' _} (1) (2) where

- module of the error signal of the dying system;

- speed of the object;

- transmission coefficient of the second 15 amplifier;

- deadband of the relay element 16.

ι

Value 8 is set small, but sufficient for reliable fulfillment of logical condition (1) in the equilibrium state of the tracking system.

The required value of the transmission coefficient k is established experimentally when adjusting the servo where I

M „! Y1 ¹ b / - n

2nd? ^k - '^<3>

- moment of inertia of the object;

- maximum engine braking torque;

- maximum speed of the object;

0 _T - braking path and speed of the object from _t to u = ω = 0.

The estimates of the arguments I, M _No. , © _t included in formula (3) can be both calculated and obtained from experiments.

The tracking system operates as follows.

At the moment of switching on, regardless of the initial mismatch θ, in particular, when Θ = 0, a logical zero signal is generated (U = 0), since due to the bias signal δ> 0, vcnpBHe (1) / 0 / - к с ² + δ

Thus, it is always closed when you turn on the key and the analog keys

10 ^ -10 ^ open.

When a signal Θ other than zero appears, the system starts to accelerate and move to an agreed position; the value of / 0 / decreases and the value of ka ² increases. At the moment when condition (2) / 0 / - is fulfilled to ω ^ζ + δ 4 0, a signal of a logical unit is formed (U = 1). According to this signal, the key 9 disconnects the signal входа from the input of the correction link 2, and the analog keys 10, -10 „, connected in parallel with the reactive elements - capacitors 17 and 18, quickly discharge them. At the same time, zero initial conditions of the correcting link 2 are set, and at the input of the second adder 3, the signal Θ * becomes equal to zero; The negative feedback tachometric circuit creates the maximum braking moment of the object, which leads to a decrease in both / 0 / and ko ⁴ . At the moment when condition (1) is fulfilled, a logical zero signal is generated (U = 0), key 9 closes, and analog keys 10 ₍ -10 „open, and the structure of h is restored

tracking prototype system. At this _5th moment, the tracking system is in the region of small values of the mismatch 9. and drive speed ω, i.e. in the vicinity of the linear zone. Therefore, when restoring the tracking loop for the position at the input of the correcting link, a small jump Θ is formed. Therefore, the transition process in the servo system caused by the jump θ and determined by the zero initial conditions of the correcting link has quality indicators that correspond to the structure of the prototype when working in the linear tracking zone. 20

In operating modes in which condition (2) is not satisfied, key 9 remains closed and tax keys 10 (-10 (, - open. Therefore, the dynamic properties of the following system are completely determined by the structure of the prototype.

The transition process when developing a large mismatch is reduced as a result of experi- mental studies in ₃₀ 3-4, while the other quality parameters of the servo system remains at a level that corresponds to the regulatory process in a linear eon.

Claims (2)

The invention relates to automatic control systems and can be used from the class of automatic control systems, in which, along with the tracking mode, one of the main modes of operation is also the mode of program installation on a given coordinate, or the mode of entry into the tracking zone. The aim of the invention is to improve the quality of control, in particular the speed in handling large discrepancies. FIG. 1 is a block diagram of the following network :; in fig. 2 is an example of the regular implementation of the corrective element and the switching unit. The following system comprises a first adder 1, a corrective element 2, a second adder 3, a first amplifier 4, a motor 5, a control object 6, a position sensor 7, a speed sensor 8, a key 9, a switching unit 10 consisting of n analog switches 10 , .10 (,, control unit 11, module extraction unit 12, third adder 13, quad 14, second amplifier 15, relay element 16 with insensitivity zone. Corrective element 2 (FIG. 2) contains capacitors 17 and 18 and resistors 19 and 20. Switching unit 10 contains analog switches 10, and 10. Denote by &amp; error signal next system at the output of the first 1 adder. The output of the control unit 11 forms the logical signal o, at / e / + 5 1, at / b / + i where / b / is the module of the error signal of the next system; object speed | coefficient transmitting the second 15 amplifier; the dead zone of the relay element 16; the value of 8 is set small but sufficient to reliably satisfy the logical condition (1) in the equilibrium state of the follow system; the required value of the transfer coefficient k is set experimentally when adjusting the next 552 system. Its approximate value can be determined using the expressions: I / 8, / .. .. 1r - .. sT object moment of inertia; maximum torque developed by the engine; maximum speed of the object; 0 ,. - the way of braking of the object from the speed u) 0. Estimates of the arguments I, M, 9, O, (O) can be both calculated and derived from experiments. The following system works as follows. At the moment of switching on regardless of the values of the initial mismatch b, in particular when, a signal of logical zero (U 0) is formed, since due to the offset signal 5 O, the condition (1) / 9 / - ko + S is always fulfilled. closed, and analog switches 10 ;, open. When signal 0, other than zero, appears, it and the system move to a consistent position; the value of / 9 / decreases and the value of ko increases. At the moment when condition (2) / 9 / - k uU is fulfilled, a signal of a logical unit (and 1) is generated. By this signal, the key 9 disconnects the signal 9 from the input of the correction link 2, and the analog switches 10, -10, connected in parallel to the reactive elements — capacitors 17 and 18, quickly discharge them. At the same time, zero initial conditions of the correction link 2 are set, and at the input of the second adder 3 the signal bc becomes zero; The negative feedback tachometer circuit creates the maximum braking moment of the object, which leads to a decrease in both / 0 / and kw values. At the moment when condition (1) is fulfilled, a logical zero (and 0) signal is generated, the key 9 closes, and the analog switches 10, -10 and open, and the structure of the tracking system of the prototype is restored. At this moment, the tracking system is in the region of small values of the error 9. and the drive speed a, i.e. in the vicinity of the linear zone. Therefore, when the tracking loop is restored, a small jump 9 is formed at the input of the corrective element. Consequently, the transition process in the real system, caused by a jump in 0 and determined by zero initial conditions, correlates with the quality indicators, which correspond to the structure of the prototype when operating in the linear tracking zone. In operation modes, in which condition (2) is not fulfilled, key 9 remains closed, and tax keys 10, -IOf, are open. Therefore, the dynamic properties of the tracking system are fully determined by the structure of the prototype. The time of the transition process during the development of large discrepancies decreases by the results of experimental studies by a factor of 3–4, while the remaining quality indicators of the tracking system remain at a level that corresponds to the regulation processes in the linear zone. . Claim 1. The following system comprises a first adder, whose input is 554 an input of the system, a control object, the output of which is connected to a speed sensor and a position sensor, the output of which is connected to the second input of the first adder, and a series-connected correction link and the second adder , characterized in that, in order to improve speed when working out large discrepancies, a control unit, a switching unit, a switch and a series-connected first amplifier and a motor are additionally introduced The output of which is connected to the input of the control object, the output of the first adder is connected via a switch to the input of the correction link, as well as to the input of the control unit, the output of which is connected to the control input of the switch and through the switching unit to the output of the speed sensor connected to BTOIMJM input: control unit and to the input of the second adder, the output of which is connected to the input of the first amplifier. 2. The tracking system of claim 1, wherein the control unit comprises a module allocation unit and a quadrant connected in series, a second amplifier, a third adder and a relay element with a dead zone, the output of which is the control unit, the second input of which is connected to the input of the quad, and the first input through the block of the module is connected to the second input of the third adder. f f t. Hsri (27gu ;. / -k2n T