SU1642579A1 - Method of start-stop control of the stepper motor and device thereof - Google Patents

Abstract

The invention relates to electrical engineering, in particular to electric drives of stepper motors of control and regulation systems. The purpose of the invention is to save electricity. The method consists in that, at the next connection of the windings at each step to the power source and reduction of the current after the half step is completed, all windings are additionally disconnected for the standing time, and when the rotor deviates from a fixed position, a correction current pulse is generated in the windings turned on the last step. The device contains a pulse generator 6, generating pulses of different duration on two outputs, an RS flip-flop 7 controlled by signals from a pulse sensor 5 with two outputs, on which pitch and half-step signals appear, and logic elements ensuring the passage of pulses from one from the outputs of the generator 6 to the inputs of the amplifiers 3. 2 p. n. f-ly, 3 ill. Yo

Description

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The invention relates to the control of electric machines and can be used in a discrete electric drive.

The purpose of the invention is to save energy.

The implementation of the method is considered on the example of the operation of the device.

FIG. 1 shows a block diagram of the device; in fig. 2 is a diagram of his work; Fig, 3 is a sequence diagram of the pulse sensor.

The device contains a distributor 1, a group of elements And 2, a group of amplifiers 3 connected to a stepper motor 4, a pulse sensor 5, a generator of 6 pulses, an RS flip-flop 7, two elements OR 8, 9, two elements AND 10, 11, an inverter 12, shaper 13.

The input of the distributor 1 and the input S of the trigger 7 are combined and are the input of the device (Fig. 1). The outputs of the distributor 1 are connected to the first inputs of a group of elements And 2, the outputs, the last - to the inputs of a group of amplifiers 3, the outputs of the amplifiers 3 - to the windings of a stepping motor 4, with the axis of which a pulse sensor 5 is rigidly connected, having two outputs - A and B. Output A, corresponding to the stable position of the rotor, is connected via the inverter 12 to the first input of the element 11 and, through the driver 13, to the first input of the element OR 8. The output B of the sensor 5, corresponding to the rotor's rotation by half a step, is connected to the input R of the trigger 7. Pr my output is Q trigger 7 Connected to the second input of the element OR 8, the output of which is connected to the first input of the element AND 10, the output of the last - to the first input of the second element OR 9, the second input of which is connected to the output of the element And 11. The inverse output Q of the trigger 7 is connected to the second input of the element AND 11, the third input of which is connected to the first output of the pulse generator b, the second output of the generator b is connected to the second input of the AND element 10, and the output of the IL-9 element to the second inputs of a group of And 2 elements.

The device works as follows.

For example, suppose that in the control device of a stepper motor with alternating switching windings (Fig. 1), the incoming pulse must change control; if before it the motor was controlled by turning on the windings F1 and F2 (Fig. 2), then with its arrival the windings F2 and FZ. The pulse sensor gives signals at the outputs A and B in accordance with the sequence diagram presented in FIG. 3,

In the device, previously set in the initial state, the position of the engine 4 corresponds to the position of the outputs of the distributor 1, and the output Q of the trigger 7

cleared.

On the first input pulse, the distributor removes the control signal of the winding F1 and sends a signal to turn on the winding of the FL of the motor 4 (Fig. 2). At the same time, the input pulse switches trigger 7. At output Q, a signal appears that passes through the element OR 8 to the element AND 10 and allows the passage of pulses from the second output of generator 6 through element OR 9 to the second inputs of the group of elements AND 2.

The windings F2 and FZ of engine 4, defined by distributor code 1, are connected to a power source with a frequency

0 determined by the second output of the generator 6. The rotor of the engine 4 begins to turn under the action of the average current in the windings. In this case, the signal at the output A of the pulse sensor 5 disappears, which so far has no effect5 on the operation of the device.

In this way, a current is generated which creates a maximum torque on the motor shaft.

Upon the passage of half a step by the rotor, a signal appears briefly at the output B of the pulse sensor 5, which switches the trigger 7, which removes the permission for the passage of pulses from the second output of the generator 6 to the control circuits

5 motor windings 4 and at the same time permits the passage through the element 11 of pulses from the first output of generator 6 to the control circuits of the motor windings 4 (since there is no signal at the output A of the driver 5,

0 then the output of the inverter 12 is the enable signal). In this case, the group of elements And 2 receives from the generator 6 pulses, forming in the windings a lower than in the previous case, the average value of current 5 ka.

The generator b can, for example, generate pulses with the same frequency, but with different durations. In this way, a smaller current is formed to bring the rotor to the next stable position. At the end of the rotor turning by one step, a signal appears at the output A of the pulse sensor, which removes the enabling signal from the first input of the element 11,

5 which prohibits the passage of pulses from the first output of the generator b to a group of elements AND 2, the windings of the engine 4 are de-energized, and the rotor stops until the next pulse appears at the output of the device.

If in the process of standing the load acts on the rotor so that it starts to deviate from the predetermined position, then when the predetermined deviation limit is reached at output A of sensor 5, the signal disappears and the driver 13 sends a signal of a certain duration to the element 10 allowing the passage of pulses from the second output of the generator b to the group of elements And 2 and further to the control circuits of the engine 4. There was no signal at the device input, and the distributor 1 retains the specified code for turning on the windings F2 and FZ.

Therefore, the windings F2 and FZ are again connected to the power source, a current flows in them, under the action of which the rotor returns to a predetermined position.

The timing of the correction current (the output pulse of the driver 13) is determined in advance from the conditions of the rotor turning at maximum load, and the driver 13 is adjusted for this time.

Thus, the method allows to generate the maximum current in the motor windings during the processing of the first half of the step, and then reduce it to a value sufficient to test the second half of the step and stop with the minimum oscillatory mode, and also to generate a correction current when the rotor of the engine deviates from position

After working off a full step, the current in the windings is disconnected and the engine stands in a fixed position, its rotor is affected due to the magnetization of the engine itself and friction in the gear. But the load response shifts the rotor. When the rotor deviation is significant, the signal from the sensor disappears at output A and the driver 13 generates a pulse to create a correction current, the duration of which is sufficient to reliably return the rotor to a predetermined position. In this case, the correction current appears only in those windings that were determined by the distributor during the last step.

The presence of a pulse sensor with two outputs makes it possible not only to fix the completion of each half step, but also to control the magnitude of the rotor deviation from a fixed position.

Disconnecting the motor from the power source for a fixed time saves energy, the more the lower the frequency of operation of the stepper motor.

Claims (2)

1. Start-stop control method stepper motor, which serves the rated current in the winding corresponding to the position of the rotor before the beginning of the step, and in the obmbtku, adjacent to it in the direction movement, control the rotor passage of each half step and, after the rotor has completed the first half step, reduce the amount of current in these windings, characterized in that, in order to save electric power, at the end of the step, the windings are turned off, the rotor position is monitored, and when it deviates from the position at the end of the step, the rated current is supplied to the windings corresponding to the specified polarity gelation, at the time of the elimination of the deviation. 2. A device for starting and stopping control of a stepper motor, comprising a distributor, a trigger, a driver, a pulse sensor, a group of amplifiers whose outputs are connected to the corresponding windings of a stepper motor, with an axis which is mechanically connected to a pulse sensor connected to the trigger input, characterized in that , with In order to save electricity, a pulse generator, two AND elements, an inverter, two OR elements and a group of AND elements are introduced, the pulse sensor is equipped with a second output, the outputs of the AND group of elements are connected to the inputs of the corresponding amplifiers, the first inputs are with the distributor outputs, the second inputs are with the output the first element OR, whose inputs are connected to the outputs of two elements AND, the first of which is connected to the output of the inverter by the first input, the second to the inverse output of the trigger, the third to the first output of the pulse generator, the second the stroke of which is connected to the first input of the second element AND, the second input of which is connected to the output of the second element OR, the first input of which is connected to the forward output of the trigger, and the second to the output of the driver, the input of which is connected to the second the output of the pulse sensor and the input of the inverter, and the S-input of the trigger is connected to the input of the distributor. FIG. 2 Fig.Z