SU1612371A1 - Device for monitoring overload of stepping motor - Google Patents

Abstract

The invention relates to electrical engineering, namely, control devices for stepper motors, and can be used in a compact drive with stepper motors. The aim of the invention is to reduce the size and weight of the drive. The mechanical overload control is carried out by analyzing the change in the frequency of the control signals from the output of the current stabilizers. Due to this, there is no need to install an electromechanical sensor on the axis of the stepper motor. Additional benefits are greater speed, the ability to monitor the performance of the power amplifier and the testing of each control pulse. The device allows the control elements to be placed not in the drive itself, but in the control equipment. 4 il.

Description

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The invention relates to the control of electric machines and can be used in a discrete electric drive, preferably with small-sized motors.

The purpose of the invention is to reduce the weight and dimensions of the drive.

FIG. 1 shows a drive circuit including a control device; in fig. 2 shows an embodiment of a pulse former; in fig. 3 shows an exemplary embodiment of a comparison unit; in fig. 4 - cyclogram of the device.

The drive contains the first I, second 2, third 3, fourth 4 phase windings of a stepper motor, first 5, second 6, third 7, fourth 8 phase switches, first 9, second 10 adjusters, first keys 11, second 12 current regulators , the first 13, the second 14 current feedback resistors, the first 15, the second 16 diodes of the control loop, distribute 17 pulses, the first 18, the second 19, the third 20, the fourth 21

forcing diodes, forcing resistor 22, forcing capacitor 23, shaper 24 pulses, first 25, second 26 comparison blocks, first 27, second 28 AND elements, OR element 29.

The drive input is the input 30 of the pulse distribution 17, the outputs 31-34, the pulse distributor is connected to the inputs of the first 5, current 7, second 6, fourth 8 phase switches, the output 35 of the current regulator 11 is connected to the input of the regulator. the key 9 and the first input of the pulse driver 24, the output 36 of the first 9 regulating switch is connected to the phase windings and 2 and the diode 15, the output 37 of the current regulator 12 is connected to the input of the control switch 10 and the second input of the pulse former 24, the output 38 of the second 10 adjustment key connected to phase winding and 3 and 4 and the diode 16. The generator 24 has outputs 39-48.

The first 39. The sixth 44 outputs of the former 24 pulses are connected to the juice inputs.

about

responsibly the first 25 and second 26 comparison units intended for initial installation, the second 40, seventh 45 outputs of the pulse generator 24 are connected to the inputs of the first 25 and second 26 comparison blocks, respectively, intended to receive the first series of pulses (when subtracted), and the third 41 , eighth 46 - for the second series of pulses (when added), fourth 42, ninth 47 outputs of the pulse former 24 are connected to the inputs of the first 25 and second 26 comparison blocks, respectively, to switch the counting direction, 43 fifth, tenth outputs 48 pulse shaper 24 connected to the second inputs respectively of the first 27 and second 28 elements AND, the output 49 of the first AND gate 27, the output 50 of the second AND gate 28 are connected to the inputs of OR element 29.

The device works as follows.

Upon receipt at the input 30 of the distributor 17 pulses of signals, the distributor 17 pulses produces a sequence of pulses on the first 31, second 32, third 33, fourth 34 outputs coming to the inputs of the first 5, third 7, second 6, fourth 8 phase switches connecting to the source power, respectively, the first 1, third 3, second 2, fourth 4 phase windings.

The first current feedback resistor 13, the first 5 or second 6 phase switches with the corresponding first 1 and second 2 phases of the stepper motor, the first 9 adjustment key, the first current regulator 11, the first diode 15 of the current control loop, operating according to the principle current path form a current control loop.

The same current control loop consists of the following elements: the second resistor 14, the third 7 and the fourth 8 phase switches, the third 3 and the fourth 4 phases of the stepper motor, the second 10 adjustment key, the second regulator 12, the second 16 control diode, the first 18, the second 19 , third 20, fourth 21 forcing diodes, forcing resistor 22, forcing capacitor 23 form a forcing circuit in the corresponding winding when it is turned off.

When the rotor of the stepper motor is rotated during rotation, a periodic change in the electromagnetic properties of the rotor-stator system and a corresponding change in the electromagnetic properties of the connected winding occur, resulting in a change in the frequency of current control in this winding. Specifically, this phenomenon is expressed in the fact that at the time of rotation in the newly connected winding the current control frequency increases significantly (50%).

On the cyclogram (Fig. 4), the time intervals of a significant increase in frequency are marked as T |, 2 for the first 1 and second 2 and as 3, 4 for the third 3 and fourth 4 windings of the stepping motor.

It should be noted that the turn affects the frequency of current regulation of the non-switched winding, but significantly less and for a shorter time interval (this is a change in the diagram

0 (Fig. 4) conventionally not shown). The diagram shown in FIG. 4 (35-38) is characteristic for the operation of a stepper motor at the frequency of pickup.

During mechanical deceleration of a stepper motor at the arrival of control

 pulses 31-34 (Fig. 4) on the phase switches 5-8, the axis of the stepping motor does not rotate within the control period of any phase, the frequency of current control in the windings is kept constant within this period and may differ by the amount of random deviations frequency control current regulator. In the diagram (Fig. 4) this is shown conditionally at the time ti. By comparing the frequency of adjustment (or the number of pulses per one and the same time interval) of the current in the phase during the time interval corresponding to the expected turn and during the time interval after the end of the expected turn, the fact of mechanical braking can be established. In this case, when pulses of signals from outputs 35 and 37, first 11 and second 12 current controllers arrive at the shaper 24 inputs, it produces pulse sequences at its outputs 39-48 according to FIG. four.

At the first 39 and sixth 44 outputs, pulses are formed, setting the corresponding comparison blocks 25 and 26 to the initial state before the start of control, at the second 40 and third 41 outputs, pulses are formed, whose frequency (or number for the same time interval) is compared (these refer to two half of the connection period of the first or second windings).

These pulses are received at the inputs of the first 27 comparison device.

At the fourth 42 output, a signal is generated in the form of a pulse determining the counting direction (in this case, the presence of an impulse — addition, no — subtraction) and related to the interval during which the fact of mechanical braking is detected.

At the 43 rd output, a permission signal is generated to pass a mechanical overload to the output through the OR element 29 through the first element 27 of the signal 29. The signals at the sixth 44, seventh 45, eighth 46, ninth 47 and ten 48 shaper outputs 24 pulses are similar

0

five

0

the signals on the first 39, second 40. third 41, fourth 42 and fifth 43 outlets. Pulse shaper 24 includes filters 50 and 51, designed to isolate the impulse of setting units 25 and 26 of the comparison to the initial position, which are, for example, an RC circuit and a Schmitt trigger. These filters delay short pulses and pass a long pulse.

This signal can be used to turn off power to a stepper motor, and can only be used to register for transient overload.

The device also has additional advantages: if during mechanical operation the mechanical load is stable, and the control of the mechanical overload is not necessary in the manufacture and testing of the drive, then the actual control unit can be set to compare Amplitude of pulses coming from second-in control equipment, which gives convenience

40 and the third 41 outputs are form-operated as compared to the known 24 pulses for the first block 25 and the performance is improved as the seventh 45 and eighth 46 outputs for the VTO overload are issued after the maximum block 2b. Comparison is performed with an accuracy of pulses, and in the well-known nocie 3-device, the magnitude of random deviations. The STEO allows additionally controlling comparison blocks to be implemented in pulsing each step, for example, as shown in FIG. 3 in the form of - three logic elements: OR 55, a reversible counter 56 and an HE element 57.

After the pulse has recorded the initial setting 39 (44) of the initial setpoint equal to twice the random deviation of the number of pulses, the counter works on subtraction, and after switching the counting direction to addition.

Thus, if the second burst of impulses arriving during work on addition is equal in the number of impulses

signals from the outputs of comparison units 25 and 26 during the operation of these devices

20 on subtraction; the signals coming from the outputs of the first 39 and the pulse 44 of the pulse generator can characterize the serviceability of the power amplifier, since a constant "O or" 1 will indicate a failure of the control device; already

 25 it is easy to equip existing drives with a means of controlling a mechanical overload without reworking your own drive.

a burst of impulses arriving during subtraction work, then a counter overflow signal is generated at output 49 (50), which indicates a mechanical overload of the stepper motor axis.

thirty

Claims (1)

Invention Formula A device for controlling a mechanical overload of a stepper motor operating .4 a pair-switching mode with pulsed stabilization of the phase current, containing the first comparison unit, the AND element, the OR element, characterized in that A device for controlling a mechanical overload of a stepper motor operating .4 a pair-switching mode with pulsed stabilization of the phase current, containing the first comparison unit, the AND element, the OR element, characterized in that The device allows you to analyze the ratio of the number of pulses on each the period of control of each phase in case of any reduction in the mass of H7 bar to introduce a type of overload. Thus, the comparison unit, the second element AND, and the pulse shaper, whose inputs are prefixed; the device allows you to control the mechanical overload on the axis of the stepper motor using only control signals . Pulse phase current regulators are usgs of current regulator outputs, which allows the driver to control the motor, and leave the control panel an i / Tr rk ravnp ,. . ,, .. l „. refuse to use an electromechanical sensor from a disk and optocouplers, i.e., the object of the invention is to achieve a reduction in the size and mass of the jog drive. It should be noted that the received signal. The mechanical overload can be used to turn off input signals, as in a known device. Besides. The initial position, pulse, and counting directions are connected to the corresponding inputs of the comparison blocks, the resolution outputs are connected to the first inputs of the AND elements, the second inputs of which are connected to the outputs of the corresponding comparison blocks, and the outputs to the inputs of the OR element. This signal can be used to turn off power to a stepper motor, and can only be used to register for transient overload. The device also has additional advantages: if during E1 operation the mechanical load is stable and the control of the mechanical overload is not necessary in the manufacture and testing of the drive, then the control device itself can be installed in the control equipment, which gives convenience to test the processing of each step of the pulse signals from the outputs of the blocks 25 and 26 of the comparison during the operation of these devices 20 on subtraction; the signals coming from the outputs of the first 39 and the pulse 44 of the pulse generator can characterize the serviceability of the power amplifier, since a constant "O or" 1 will indicate a failure of the control device; already  25 it is easy to equip existing drives with a means of controlling a mechanical overload without reworking your own drive. Invention Formula A device for controlling a mechanical overload of a stepper motor operating .4 a pair-switching mode with pulsed stabilization of the phase current, containing the first comparison unit, the AND element, the OR element, characterized in that , the reduction of the mass of H7A bar ites injected into the unit of comparison, the second element AND and the formulas for controlling the engine, and the output ,. . ,, .. l „. The initial position, pulse, and counting directions are connected to the corresponding inputs of the comparison blocks, the resolution outputs are connected to the first inputs of the AND elements, the second inputs of which are connected to the outputs of the corresponding comparison blocks, and the outputs to the inputs of the OR element. about- 35 J 37 Mlhh &one beginning reset Fi.5 39 53 40 44 45 41 48 FIG. 2 SO SI li 33 f / lld / lvlch vvv A / yVvVvVMVvv / v v / -, t. 4 1 1 ;; П ППППт 1П I I, V I; 1 11 111 U 1 t vVWA AWVVvA / y MV / J ..... .i Jl. U I lit mm yy aich The same I: i c. U J. iiffn Jsii A nT- i W (. 4 one Ji one Jl. EH iiffn one a u-d-i dzdsh11y a | L