SU1677844A1 - Device for controlling stepping motor - Google Patents

Abstract

The invention relates to electrical engineering and can be used to create a discrete electric drive with a high-speed protection system for an object with a limited range of movement. The purpose of the invention is to increase the speed at which a fault is issued. Only in two out of thirteen possible emergency situations, which at the initial moment are not different from normal situations, the issue of an alarm with motion blocking is performed with the minimum necessary delay. In the remaining eleven fault situations, the device issues an alarm signal and blocks the movement of the object immediately after the occurrence of a fault. For this, sensor 4 of the limiting positions of the movable part contains a control output, the alarm of which appears due to the new version of the sensor in case of any deviation of the combination of signals on the communication lines of the limit switches 19 and 20 from the standard combinations. 1 hp f-ly, 2 ill. Yo

Description

The invention relates to the control of electric machines and can be used to create a discrete electric drive with a high-speed protection system for an object with a limited range of movement.

The purpose of the invention is to increase the speed at which a fault is issued.

FIG. 1 is a functional block diagram of a device for controlling a stepper motor; in fig. 2 - voltage plots in the nodal points of the circuit at the outputs of the elements, the reference designation of which is indicated in brackets next to the sequence number of each voltage plot.

The device for controlling the stepper motor includes a clock bus 1, a motion resolution bus 2, a reverse bus 3, a sensor 4 for the limiting positions of the movable part, element 5, a counter 6, an alarm condition indicator 7 and a control unit 8 whose direction input is connected to bus 3 the reverse, the blocking inputs are connected to the control outputs of the sensor 4 limit positions of the movable part, the clock input is connected to the output of the element And 5, the first input of which is connected to the clock bus 1 of the device, the second input is combined with the first input indicator and 7 is an alarm condition and is connected to the output of the counter 6, the third input is combined with the second input of the indicator 7 of the alarm condition and connected to the control output of the sensor 4 of the limiting positions of the moving part

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The fourth input is connected to the motion resolution bus 2, and the output of the element 5 is connected to the counting input of the counter 6, the zero-state input of which is connected to the information output of the sensor 4 of the limiting positions of the moving part including the first 9 and second 10 inverters , the first 11, the second 12, the third 13, the fourth 14 and the fifth 15 elements 3 AND-NOT, the element EXCLUSIVE OR 16, the first 17 and second 18 triggers, the installation inputs of which are connected to the zero potential bus through switches 19 and 20 resistors 21, 22, 23, 24 are connected With the power bus, the outputs of the flip-flops 17 and 18 are the control outputs of the sensor 4, the limiting positions of the moving part, the first inputs of the first 11 and second 12 elements 3 are NOT connected to the output of the first inverter 9, the input of which is connected to the first inputs of the third element 3 AND-NO 13, the EXCLUSIVE OR 16 element and connected to the installation input in the single state of the first trigger 17, the installation input in the zero state of which is combined with the second inputs of the first 11 and second 12 elements 3 AND-NOT and associated with the first input of the fourth element 3 AND-NOT 14, output Expensive is the information output of the sensor 4 of the limiting positions of the movable part, the second input is connected to the input of the EXCLUSIVE OR 16 element, the second input of which is combined with the installation input in the unit state of the second trigger 18, the third input of the first element 3 AND-NE 11 and through the second inverter 10 is connected with the second input of the third element 3 AND-NOT 13, the third input of which is combined with the third inputs of the second 12 and fourth 14 elements 3 AND-NOT and is connected with the installation input to the zero state of the second trigger 18, the outputs of the first 11, second 12 and the third 13 elements 3 AND-NOT are connected to the inputs of the fifth element 3 AND-NOT 15, the output of which is the control output of the sensor 4 of the limiting positions of the movable part.

The device works as follows.

At the initial moment of time PT, when the device is turned on, the movable part of the controlled object is in an intermediate position outside the zones controlled by limit switches 19 and 20. At the same time, the switches 19 and 20 are not pressed to turn on the device first 17 (plot 25) and second 18 (plot 26) the flip-flops are set to one state due to the low-level signal being applied through the opening contacts of the limit switches 19 and 20 to the S inputs of the flip-flops 17 and 18. With the outputs of the first 11 (plot 27) and the third 13 (plot 28) of elements 3 And -NO in this case logical unit is set

(zero level at the third input of the first 11 and the first input of the third 13 elements 3 AND-NOT), while the output of the second element 3 IS-NOT 12 (plot 29) contains a low level signal, since all inputs

0 of this element, taking into account the signal inversion on the element 9. high level signals (logical units) are given. Thus, from the output of the fifth element 3 AND-NOT 15, i.e. from the control output of the sensor 4 limit

5 positions of the movable part, the input of the indicator 7 and the third input of the element And 5 receive a high level signal (plot 30), confirming the absence of an emergency condition of the sensor 4 and removing the lock from the element 5 on its third input. At the outputs of the EXCLUSIVE OR 16 element, when the device is turned on under the above conditions, there are signals of the same (low) level, causing

5 is a low level signal at the second input of the fourth element 3 AND-NOT 14. From the output of this element used as information output of sensor 4, to the input of setting to the zero state of counter 6

0 receives a high level signal (plot 31), providing a reset of counter 6. At the output of counter 6 (plot 32) and, respectively, at the second input of element 5, a high level signal is set.

5So, when the device is turned on under the specified conditions and in good condition, the limit switches 19, 20 and their communication lines with the device at the control, information and control output of the sensor 4 of the limiting positions of the moving part are set to allow potential signals of high level. When a high level signal is applied at time J to the bus 2 of the travel permit (plot 33) and, accordingly, to the fourth input of the AND element 5, the clock pulses from the clock bus 1 (plot 34) are passed to the output of the And 5 element (plot 35) and arrive to the clock input of the control unit 8, the outputs of which thus form a predetermined sequence of control signals, ensuring the rotation of the stepping motor, and the direction of rotation is determined by the level

5 of a potential signal on bus 3. If, at a high level, a signal on bus 3, the movement of the movable part occurs in the direction of the limit position controlled by the limit switch 19, then when the limit position is reached at time Tz, the switching contact of the limit switch 19 begins to move away from the break contact with some bounce, causing the corresponding signal drops at the output of the EXCLUSIVE or 16 element and the second input of the fourth element 3 AND-NOT 14, on the first and third inputs of which are present with Signals of high level. The bounce of the switching contact is thus repeated at the output of the fourth element 3 AND-HE 14 (plot 31), i.e. on the information output of the sensor 4, causing the periodical turning on of the counter 6 with the possible timing of the clock pulse and the subsequent reset of the counter to the initial zero state. At the same time, the control output of sensor 4 (plot 30) at the same time continues to maintain a high level signal, which is provided during bounce by alternately maintaining a low level signal at the output of the second 12 (plot 29) or the third 13 (plot 28) of the 3 AND- NOT elements.

Upon receipt of the following clock pulses, further displacement of the moving part of the object and the pushing of the limit switch 19 occurs, causing the chattering to stop and the final separation of the switching contact by the time T4. At the inputs of the EXCLUSIVE or 16 element, up to the contact of the switching contact with the closing one, there are signals of different levels causing a high level signal at the output of this element and, accordingly, at the second input of the fourth element ZI-HE 14, at the first input of which the signal is also maintained during the transfer of the switching contact high level, as well as at the third input of this element in the normal state of limit switch 20 controlling the opposite limit position. At the input of the zero setting of the counter 6, during the transfer of the contact from the output of the element 14 (plot 21), a low level signal is applied, enabling the counting, and the counter 6 starts counting the contact pulses. After supplying a certain number of clock pulses required to test the zone of limit switch 19, the switching contact at time Ts will enter into contact with the closing contact and cause the first trigger 17 to transfer to the zero state (plot 25).

The low level signal from the output of this trigger, arriving at the corresponding input of the blocking element 8, will block further movement of the moving part of the object in this direction. The counter 6 at the same time counted the number of clock pulses necessary for the standard development of the limit switch zone 19, i.e. for hitting the movable part of the controlled object on the switch, and this number

2-3 pulses less than the number decoded at the output of the counter. At the first contact of the switching contact with the closing contact at the time Ts at the first

A low level signal appears at the input 4 of the fourth element 3 NAND 14, causing the counter 6 to be reset and a high signal maintained at its output (plot 32). At the control output of sensor 4 with

A 5th good second limit switch 20 and a regular development of the zone of the first switch 19 also support a high level signal (plot 30), since the output of the third element ZI-HE 13 (plot 28)

0 there is a low level signal due to the presence of high level signals on all inputs of this element.

Upon subsequent change in the direction of movement (for example, at the time of Te) by sending a low signal to bus 3, the mobile part leaves the zone of the limit switch 19 with recalculation of the last and contact bounce similar to the above, but with the first trigger 17 set to one state at time T (plot 25). If, after leaving the zone of limit switch 19 at the time of Te and further, the direction of movement does not change, then the mobile

Part 5 with its further movement reaches, for example, at the moment of time TD of the zone controlled by the limit switch 20, with the subsequent transfer of the second trigger 18 (plot 26, point in time

0 q) to the zero state. When the limit switch 20 zone is regularly tested and the limit switch 19 is in a good condition, there is no alarm at the test output of sensor 4, i.e. high signal

Level 5 at the output of element 15 is provided, including alternately with signals, of a low level at the outputs of the second 12 (plot 29) and the first 11 (plot 27) of the 3 AND-NOT elements, while the zone itself is calculated by the counter 6 separately in and in the opposite directions as in the case of the first limiting position.

In the general case, the signal of the absence of an alarm at the control output of the sensor 4 pod5 is maintained only with standard combinations of signals taken from the contacts of the limit switches 19, 20 and corresponding to the following regular operating situations:

the movable part is in an intermediate position, both limit switches 19 and 20 are not pressed;

the movable part in the first limit position, the limit switch 19 is pressed, the switch 20 is not pressed;

limit switch zone

19, high level signals are present at its opening and closing contacts; switch 20 is not pressed;

the movable part in the second limit position, the limit switch 20 is pressed, the switch 19 is not pressed;

limit switch zone

20, high level signals are present at its opening and closing contacts; switch 19 is not pressed.

All other combinations of these signals are a consequence of the failure of one or both of the limit switches 19, 20 or their communication lines with the device and correspond to the following fault situations in the sensor 4 of the limiting positions of the moving part;

shorting the contacts or communication lines of the limit switch 19 to the common bus in any state of the switch 20 - a low signal at the second input of the first 11, the second input of the second 12 and the first input of the third 13 AND-NOT elements;

shorting the contacts or communication lines of the limit switch 20 in any state of the switch 19 is a low level signal at the third inputs of the first 11, second 12 and third 13 AND-3 elements;

simultaneously pressing both switches 19, 20 is a low level signal at the first and second inputs of element 11, all inputs of element 12 and the second, third inputs of element 13;

pressing the limit switch 19 when developing the zone of the switch 20 - a low level signal at the first and second inputs of the elements 11,12 and the second input of the element 13;

pressing the limit switch 20 when developing the zone of the switch 19 is a low level signal at the first input of the element 11, the first and third inputs of the element 12. the second and third inputs of the element 13;

failure of both limit switches or interruption of their communication lines (high level signal on all communication lines) is a low level signal at the first inputs of elements 11, 12 and the second input of element 13.

In any of the cases listed, the total number of which is 11, at the outputs of the first 11, second 12 and third 13 elements 3 NAND, for example, at time Ti t with simultaneous operation of switches 19 and 20 (or shorting

on a common bus), high level signals will occur, causing a low level signal at the output of the fifth IS-NE 15 element (plot 30), i.e. on the control

output sensor 4. Arrival at the third input element And 5, this signal blocks the passage of clock pulses (plot 35) and thus further movement of the movable part. The alarm indicator 7 is turned on by the same signal. If the communication lines are broken or if one of the limit switches, for example switch 19, breaks at time Ti2. but in the normal state of the switch 20, the possible failure situation in the initial period does not differ in its essence from the normal one when the zone of the corresponding limit switch is worked out and is calculated by the counter 6. When the number is reached,

0 a decoded output of counter 6 and corresponding to the displacement of the moving part exceeding the dimensions of the zone, a low level signal appears at the output of counter 6 (plot 32) at the moment of time Ттз,

5 which blocks the passage of clock pulses through the element And 5 and causes the stop of the stepper motor. The low level signal from the output of the counter 6 turns on and the alarm 7 indicator 7.

0 Thus, a device for controlling a stepper motor provides higher speed in analyzing faulty situations, blocking the movement of the moving part with the minimum required delay only in two emergency situations that are not different at the moment of their occurrence from regular situations. In all other possible 11 failure situations, the blocking of movement with

0, issuing an alarm signal is performed immediately after the occurrence of a fault in the limit position sensor. In the event of a malfunction while stationary, the device also gives an alarm signal and eliminates the possibility

5 further moving into 11 of 13 failed situations.

Claims (2)

Claim 1. Device for controlling a stepper motor, comprising a resolution bus 0 motion, the sensor of the limiting positions of the movable part, the element I, the counter and the control unit, whose blocking inputs are connected to the control outputs of the sensor of the limit positions of the mobile part, the direction input is connected to the reverse bus, the clock input is connected to the output of the element I, the first input of which connected to the clock bus device, the second input is connected to the output of the counter, the input of the installation in the zero state of which is connected to The information output of the sensor of the limiting positions of the movable part, characterized in that, in order to increase the speed of issuing a fault signal, the sensor of the limiting positions of the movable part has a control output connected to the third input element I, the fourth input of which is connected to the motion resolution bus, and the output of the element And connected to the counting input of the counter. 2. The device pop. H. distinguishing with the fact that the sensor of the limiting positions of the movable part contains two inverters, the first, second, third, fourth and fifth elements 3 AND-NOT, the element EXCLUSIVE OR, and two triggers, mustache, envochnye inputs of each of which are connected to one of the limit switches, and the trigger outputs are the control outputs of the sensor of the limiting positions of the movable part, the first inputs of the first and second elements 3 are NOT connected to the output of the first inverter, whose input is connected to the first inputs of the third element 3 I0 five 0 NO, the EXCLUSIVE OR element is connected to the setup input of the first trigger, the second installation input of which is combined with the second inputs of the first and second elements 3 AND-NOT and connected to the first input of the fourth element 3 AND-NOT, the output of the second positions of the movable part, the second input is connected to the output of the EXCLUSIVE OR element, the second input of which is combined with one of the installation inputs of the second trigger, the third input of the first element 3 AND-NOT and through the second inverter is connected to the second input the house of the third element 3 AND-NOT, whose third input is combined with the third inputs of the second and fourth elements 3 AND-NOT and connected to the second installation input of the second trigger, the outputs of the first, second and third elements 3 AND-NOT are connected to the inputs of the fifth element 3 AND-NOT, the output of which is the control output of the sensor of the limit positions of the movable part. CSR Ti TЈ Tj TV Ts Te T7 Tg Ts Ty Ty Trg TVs FI.2