SU1203480A1 - Servo system - Google Patents

Description

 ,

And;) gaining access to automated control systems and can be used in designing follow-up systems that have a limited speed and angle of rotation of the output shaft, operating from a limited power source, for example, in automatic control systems for optical telescopes and radio telescopes.

The purpose of the invention is to improve the accuracy of the system when braking the control circuit and in the case of iiSMener, the voltage of the field winding, for example, due to the overload of the mains supply. i

The drawing shows a block diagram of a tracking system.

The following system comprises driver 1, comparison element 2, amplifier 3, engine 4, excitation winding 5, gearbox 6, control object 7, feedback sensor 8, limit switch unit 9, speed sensor 10, sensor for winding current, functional converter 12, element

13 with adjustable dead band, power bus 14.

The proposed system works as follows.

The signal proportional to the specified angular position of the control object from the output of the driver 1 is fed to the first input of the comparison element 2, to the subtractive input of which from the output of the feedback sensor 8 receives a signal proportional to the current angular position of the adjustment object 7.

The error signal from the output element

2 comparison is fed to the first input of amplifier 3 (input of the preamplifier PU), where it is processed with correction devices in order to ensure the stability of the system and is amplified by voltage (LL) and power.:; 1 (MIND) to the value required for motor control 4. Engine 4 through the gearbox 6, deploys the control object 7 and associated with the feedback sensor 8 and the cam of the block 9 of the limit switches. Directly to the motor shaft 4 is a speed sensor 10, which produces a signal proportional to the speed of the system.

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The signal from the output of the speed sensor 10 is fed to the first input of the element 13 with an adjustable deadband, to the control 5 input of which a signal is output from the output of the functional transducer

12 (square root with constraint). The functional converter 12 sets the value of the zone of inactivity of the element 13 as a function of the current of the excitation winding 5 of the engine 4. A signal proportional to the excitation current of the engine (and, consequently, the torque developed

15), is removed from the output of the sensor 11 of the excitation winding current connected in series with the excitation winding 5 to the power supply 14 of limited power.

20 At a certain system speed, the dead band of an element

13 will be selected. In this case, the error signal is shunted by the low-resistance output resistance of the sensor 10 speed, and the first input of the amplifier 3 receives a signal of a hard negative, feedback on the system speed, resulting in a further increase in the system speed,

30 i.e. the maximum speed of the system is limited.

When the system approaches the end positions, the cam of the block 9 of the limit switches closes one of the switch switches, as a result of which the second input of the amplifier 3 is short-circuited and the engine switches to the dynamic braking mode.

When the excitation current changes

4Q of the motor 4 within the nominal limits of the functional converter 12 generates the maximum constant signal and the magnitude of the system speed limit is maximum.

(5 This speed determines the minimum allowable installation angle of the limit switches, which is measured from the mechanical stops (end positions).

 If during the operation of the system the motor excitation current decreases due to the overload of the power source of limited power, and the maximum system speed remains constant (d, then when the limit switches are triggered, the system deceleration angle becomes different due to the decrease in ms

engine developed by braking. Increasing the braking angle may result in breakage of the mechanical stops or damage to the control object.

In the proposed device, when the excitation current of the engine is reduced by AND-times compared to the nominal value, the dead zone of the element 13 is automatically

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reduced by block 12 signal by NlTi times. As a result, the dead zone of the functional converter 12 will be selected 5 at a system speed of n times less than the maximum, and the system will reach the end positions at a lower speed such that the braking angle of the system remains constant.

Claims (1)

A NEXT SYSTEM containing a series-connected amplifier, motor, gearbox and control object, the input of which is connected to the limit switch unit and through a feedback sensor with a subtracting input of the comparison element, the summing input of which is connected to the master device, a speed sensor mounted on the motor shaft, connected through an element with an adjustable deadband to the first input of the amplifier, one output of the excitation winding of the motor is connected to one power bus, characterized in that, for the purpose of To increase the accuracy of the system, an additional field current sensor and a functional converter are additionally introduced into it, the output of which is connected to the control input of the element with an adjustable dead zone, the output of the limit switch block is connected to the second input of the amplifier, the first input of which is connected to the output of the comparison element, the sensor the field winding current is installed between the other terminal of the field winding and another power bus.