SU1525677A1 - Electric drive - Google Patents

Abstract

The invention relates to electrical engineering, namely to electric drive, and can be used in installations with periodically varying displaceable mass, carrying out linear movement and precise positioning. The aim of the invention is to improve the positioning accuracy of the actuator. The drive contains a task unit, a pulse counter, a digital-to-analog converter, a position controller, a switch, a voltage regulator, a motor, and a pulse displacement sensor, the output of which is connected to the counting input of a pulse counter, the outputs of the higher bits of which are connected to the control input of the switch. An additional key element and a dot-rate speed sensor are added to the drive, the key element is installed between the switch and the voltage regulator, the output of the dot-speed speed sensor is connected to the group of control inputs of the key element, and the switch input is connected to its information input The dot giv rate is the output of a pulse displacement sensor. The invention can be used in electric industrial robots. 3 il.

Description

The invention relates to electrical engineering, in particular to electric drives, and can be used in installations with periodically varying moving mass, requiring linear movement and precise positioning, for example, in industrial robots.

The purpose of the invention is to improve the accuracy of positioning of the executive body.

FIG. 1 shows a functional diagram of the drive; Fig. 2 shows an electrical circuit diagram of a key and a speed sensor for torque sensing; in fig. 3 - the electrical circuit of an impulse counter, a digital-analog converter, a position controller and a switch;

The electric drive contains a task block I, a pulse counter 2, a digital-to-analog converter For the k position controller, switch 5, key terminal 6, voltage controller 7, motor 8, displacement pulse sensor 9 and dot-down speed sensor 10,

; Sensor 10 of the speed dotvivani with | contains an integrating chain 11} consisting of a shunt diode 12, a resistor 13 and a capacitor, resistors 15-17, a comparator 18, a matching circuit 19 consisting of a.-ZAHHCopa 20 -NOT 22.

The key element 6 form the switch 23, the amplifier 2 and the capacitor 25.

The pulse counter contains a 26 high-order counter and a 27 low-order counter.

The position controller is formed by an amplifier 28 and a feedback variable resistor 29.

Switch 5 consists of the elements OR NOT 30, the element AND 31, the element AND NOT and the key 33.

The signal a permits the operation of the NAND element 22 to avoid the false triggering of the element NAND 22 when the engine 8 is accelerated when the speed of the engine 8 is equal to the speed dot givan. The reset signal b is generated in the form O at the output of the counter 27 lower bits when the executive body reaches the required positioning point,

In the dot-on-low speed mode, up to the positioning point, the speed does not depend on the size of the mass being moved. The latter condition is achieved by the fact that the supply voltage supplied to the engine 8 from the voltage regulator 7 is stabilized at the level at which the speed of the engine 8 is equal to the speed of accumulation.

When the positioning point is reached, the engine B is turned off, but the actuator continues to move and travels the path determined by the kinematic energy and resistance to movement (with

no special devices):

1 brake

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the path traveled by the executive body from the moment the engine 8 is turned off to a full stop; displaced mass; resistance to movement; Executive speed at engine shutdown.

When using a cylindrical linear motor (asynchronous) with the installation of a moving secondary element on the sliding bearings, the connection between the resistance to movement F and the displaced mass m can be expressed through the coefficient of friction in the bearings of the supports f:

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Thus, the resisting force F is proportional to the displaced mass, t, therefore, the stopping distance S is determined by the speed of the actuator at the moment the engine is turned off.

The drive works as follows.

From the setting unit 1, the value of the required movement in the form of a digital binary code is transmitted to the preset input of the 2 pulse counter. The recording is made with a short pulse in the form of O, applied to the input of the counters 2b and 27 mln. Of senior and senior bits. When implementing an electric drive, the distances at which the switch 5 and the element NE22 will operate are predetermined. In this example, these distances are. Press 31 and 7 pulses to the stop point, respectively.

The signal that the distance to the positioning point is less than or equal to 31, in the form of 1, is formed at the output of the element OR-NOT 30, at the input of which the most significant bits of the counter 2 pulses are applied. A signal in the form of 1 appears on the exit of the element And 31, if the distance to the positioning point is less than or equal to 7.

The lower five bits of the counter 2 pulses (giving the maximum number of AOs are connected to the inputs of the digital-analog converter 3 Outputs

a digital-to-analog converter 3 is connected to the inputs of the position controller k. The transfer coefficient of the position controller is determined by the variable feedback resistor 29.

After specifying large shifts (more than 31 pulses), the output of the element OR NONE 30 is O, so the output of at least one of the high bits of the counter 2 pulses (the outputs of the counter 27 high bits) is present 1. At the same time, on the digital input of the key 33 O is present, at the analog input of switch 33 there is a maximum control voltage signal.

For small movements (less than 31 pulses), the output of the element OR NONE 30 is 1, This signal is inverted by the element AND NRE 32 and in the form O is fed to the input of the key 33. As a result, the analog signal from the position controller is passed through the output of the key 33 arriving at the input of the key 33 The magnitude of this signal is proportional to the distance remaining to the positioning point. Next, the control signal from the output of the switch 5 is fed to the input of the switch b (the input of the switch 23).

The circuitry of the speed sensor 10, the output of which is fed to the digital inputs D1 and D2 of the key element switch 23, allows the control signal from the switch 5 to pass through the key element of the voltage regulator 7 input. At the same time, at the input D1 of the switch 23, O is present, and at the input of D2 - 1. From the voltage regulator 7, the supply voltage is supplied to the motor 8 and it starts to move. At the same time, the impulse transducer 9 generates impulses for the repetition of the displacement, the number of which determines the distance traveled, and the duration of each impulse characterizes the speed of movement at a given moment. The pulses from the pulse displacement sensor 9 are fed to the counting input of the counter 2 pulses (the counter input is 27 lower bits), with the result that the numerical code at the output of the counter 2 pulses at each time point corresponds to the distance to the positioning point. Until switch 5 trips (in this case, when

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when over 31) the motor 8 is controlled by the maximum voltage (c "arriving at the input of the switch 33) After the switch 5 trips, the voltage at the motor 8 is determined by a signal from regulator A of the position, which corresponds to the numeric code at the output of the pulse counter 2. Consequently, when approaching the positioning point, the power supply voltage of the engine 8 decreases and the speed also decreases. The duration of the pulses generated by the pulse displacement sensor 9 increases with decreasing speed. the stroke of the pulse displacement sensor 9 is fed to the input of the speed sensor 10, and the capacitor 1 is charged for the duration of the pulse, and therefore the voltage on the non-inverting input of the comparator 18 rises. During the pause, the capacitor 1 is quickly discharged through the shunt diode 12.

By reducing the speed of the motor 8 to the speed of dotting, the pulse duration becomes sufficient for the voltage across the capacitor to increase to a value greater than the voltage of the set point at the inverting input of the comparator 18. At the output of the comparator 18 appears 1. At the same time, at the output of the element IS-NOT 22, O appears, which is blocked through feedback. Thereafter, the zero signal at the output 8 of the element IS-NOT 22 does not change during the whole time of movement to the positioning point.

At the moment of the appearance of the O element 22 of the signal O, the key element 6 is activated, in which the control inputs change at the digital inputs D1 and D2 of the switch 23. As a result, one analog input of the switch 23 is closed, and the other is connected to the output of the amplifier 24 and then through the amplifier 2C to the input of the voltage regulator 7. Since the input of the switch 23 is connected to the output of the amplifier 24, the voltage regulator 7 then receives a signal equal to the last value of the signal received from the position controller 4 before the triggering of the key element 6.

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Thus, the supply voltage of the engine 8 is stabilized at the level at which the speed of the engine 3 is equal to the speed of reaching the point. With further moving to the positioning point, the supply voltage of the engine 8, and therefore, the speed remains unchanged.

Thus, in the dot-drive mode for different displaced masses, the engine supply voltage is different, but the speed of movement is constant and independent of the size of the displaced mass, and therefore, the path taken by the executive body after the engine is turned off is constant, and the accuracy of positioning.

Claims (1)

Invention Formula The actuator containing the block of the task of movement, the output connection 67 Jq fg 0  eight P2NNY K C1.; To a pulse cell a digital-to-analog converter, psiv; position torus, -komutator, pery.nH i -; j voltage, dzzigatel, pulse sensor of alternation; The output of which is connected to the estimated input of the pulse counter, the outputs of the higher-order bits of which are connected to the control input of the switch, which is connected with the fact that, in order to improve the accuracy of the positioning of the executive The body also additionally introduces a speed sensor for dov givania and a key element, information input of the clamp element is connected to the output of the switch, a group of control inputs with an input of the speed sensor dov givania, the output of the key element is connected to the input of the horn, voltage regulator, 5 in q dot tightening speed sensor connected to the output pulse generator g.ereme- scheni " FIG. one FIG. 2