SU1591179A1 - Apparatus for detecting fallures in stepping electric drive - Google Patents

Description

The invention relates to electrical engineering and can be used in

control systems of stepper motors with any number of phases in the context of increased requirements for the reliability of discrete electric drives. The purpose of the invention is the extension of functionality by providing control of failures in asymmetric modes of switching phases. The device contains elements AND 11, OR-NOT 12,

OR 10, ZILI-NOT 14 with gating, trigger 9, one-shot 8, two tires

6.7 job tact switching and element 13 parity. Detection of deviations from a given symmetric or asymmetric switching algorithm is provided, in t, h. shorting the motor windings to the power bus and abnormal de-energization. 1 il.

ςπ

>

3

1591179

four

The invention relates to the control of electric machines and can be used in control systems of stepper motors with any number of phases under the conditions of the reliability requirements for the operation of stepper motors.

 The purpose of the invention is to expand the functional possibilities by providing fault control in asymmetrical switching modes.

The drawing shows the functional scheme of the proposed device. 15

A device for detecting failures in a stepper electric drive equipped with tires 1–3, respectively, clock pulses, switching on the engine and reverse, connected to the inputs of the commutator 4 phases, whose outputs are connected with the corresponding phases of the stepper motor 5, contains buses 6 and 7 of the switching tact , one-shot 8; trigger 9, element OR 10, 25

element 11 and element OR NOT 12, element 13 parity control and element ZILI NOT 14 with gating, the output of which is the output of the device, and the inputs are connected to the outputs of the elements. mA 11, OR-NOT 12, connected by their inputs to the outputs of the 4-phase switch, and to the output of the parity control element 13, the information inputs of which are connected to the outputs of the switch 4 dd phases, and the parity inputs (P1 and P2) are connected to the direct and inverse the outputs of the trigger 9, the installation of 8 - and quids of which are connected with tires 6 and 7 tasks of tact switching, counting-dd. The new C input is connected to the clock bus 1 and is combined with the second input of the one-shot 8, the first input of which is connected to the bus 2 on the engine and combined with the first input of the 45th element OR 10, the second input of which is connected to the outputs of the one-shot 8, and the output is connected to the input gating element ZILI-NOT.

The device works as follows,

When the device is turned on and the stepper motor drive on the motor turn-on bus 2, a low potential is set, causing the dd switch of the 4 phases to switch off and thereby de-energize the windings of the stepping motor 5. Continuing through the OR 10 element, providing low-level signal addition, to the gate input of the ZILI element 14, the low level signal from bus 2 blocks this element, causing a high level signal at its output and preventing the high level signal from the output of the OR-NO 12 element from passing through the element 14 due to the presence of low-level signals at all its inputs due to the de-energized state of the stepper motor 5.

Before turning on the stepper motor 5, i.e. Before a potential high level signal is applied to bus 2, potential signals are supplied to buses 6 and 7 of the tact switching task, the levels of which are determined by the selected switching mode and the number of motor windings that are turned on during each cycle. By setting the trigger 9 to one of the fixed states (single or zero), or allowing the trigger to operate in the counting mode, these levels cause an appropriate combination of signals at the parity inputs P1 and P2 of the parity control element 13, which implements the parity function depending on this combination , oddness control or evenness control - oddness for signals arriving at the information inputs of the element 13.

The combinations of potential signals on chains 6 and 7 of the task of switching sensitivity depending on the selected switching mode and the number of motor windings switched on each clock cycle, as well as the corresponding signal levels at the parity inputs and output of the element 13 with the standard operating modes of a stepper electric drive are shown in the table.

I

After preparing the device for operation and selecting the direction of movement by the level of the potential signal on the bus 3 reverse, a potential high level signal is sent to the motor turn-on bus 2, the 4-phase switch permitting operation, which provides the initial energization of the stepper motor windings for this signal in accordance with the selected switching mode, Simultaneously, the differential signal on bus 2 (the transition from "0" to "1") starts. one-shot 8, generating a negative impulse, dlintel1591179

which is determined by the time required to complete the transients in the 4-phase switch and windings of the stepping motor 5. By passing through the element ILY-T © ’. on. input gating element 14, this pulse continues to keep the element 14 in the locked state (after unlocking the first input element or OR 10) until the end of the mentioned transients. After removing the strobe, i.e. releasing of the ZIPPI-NE 14 element, and when the stepping motor is normally switched on - if the number of stepper motor windings corresponds to the specified switching mode (even / odd criterion) and at least one switched on and at least one de-energized motor winding is 20 The inputs of element 14 are present! low level, causing a high level signal, i.e. the signal of no failure at the output of the element 14 and after removal .. 25

strobe until the arrival of the clock pulse.

When a negative clock pulse is applied, the combination of signals at the output of the phase switch changes to 30

according to the specified switching mode, causing the development of a step engine. At the same time, at the beginning (difference from "1" to "0") of a clock pulse arriving at the second input of dd-single-oscillator 8, a one-shot starts and a negative pulse is formed that blocks the element ZIT.AND-.CHE 14 during transients. Clock pulse from bus 1 40

The trigger 8 is also supplied to the counting input; however, with symmetric switching modes, the trigger according to the table below is constantly under the influence of a signal through one of the 45 installation inputs, ensuring that the potential signals on the parity inputs of the element 13 remain unchanged, - 50 binations of signals at information inputs, i.e. at the outputs of the switch 4 phases. Thereby, a low level signal is maintained at the output of element 13 during normal operation of the phase commutator and the stepper motor.

When selecting asymmetric switching modes, the trigger lock is removed by the installation inputs and the trigger is removed

starts working in the counting mode, changing its state for each _hour clock pulse (transition from "0" to "1") before removing the strobe, i.e. until the end of the negative pulse generated by the one-shot 8. Thus, after the application of each clock pulse and the change in the number of motor windings turned on (decrease or increase by one), the combination of signals at the parity inputs of the element 13 also changes, causing the low level signal to be maintained at output element 13.

Any disconnection from a given switching mode, for example, shorting one of the non-connected windings or breaking one of the included motor windings, also causes a similar failure in the 4-phase switch due to the failure of the power key element immediately leads to parity violation and the appearance of a high level signal at the output of element 13 parity and thus a low level signal, i.e. signal failure at the output of the element ZPLP-Ye, which is the output device. This signal can be used ddya drive off, the lock clock, alarm and m. N _n

Similarly, a failure signal is issued within a half-cycle switching and in more complex and rare failure situations. For example, when sn - ·· tune to the power bus of two windings of a four-phase motor operating in c-symmetrical pair-commutated mode, a failure signal is issued immediately after s ·.;. ·, Due to the appearance of a high level signal at the output of element 13 in two There are three possible faulty variants for switching on windings or at the output of an element 11 in the last version, when the short windings supplement the number of normally connected windings up to four and thereby at all inputs of the element r. in the case of a four-phase motor, high-level signals are present, which is identical to this type of failure as shorting all motor windings by. power bus The failure signal is issued by the device even if it is abnormal (not by sending a low level signal to the turn-on bus).

Ί

1591179

eight

gala) de-energizing the motor windings, for example, due to the break of the power supply. All the inputs of OR-NO element 12 are present at the same low level signals obuslavlivayu- ³ schio high potential at the output member 12 and thus failure signal output device.

Thus, the device for detecting failures in a stepper motor has, in comparison with the prototype, broader functionality, providing prompt detection of failures in a stepper, motor drive, the motor windings of which are switched both in symmetrical and asymmetrical modes. The main control functions are implemented using a simpler (2θ) combination block that is controlled by potential signals and does not require for its work the formation of recording pulses and the shift of information required by the prototype. 25

Claims (1)

Claim A device for detecting failures in a stepper electric drive equipped with a rear phase switch and connected to its inputs with tires of clock pulses, reverse and engine start, containing a one-shot and an element OR connected by its first inputs to the engine enable bus, a trigger, an AND element, an OR-NOT element and a ZILINE element with gating, the first and second inputs of which are connected to the element outputs And and OR-NOT, the inputs of which are connected to the outputs of the phase switch, characterized in that, in order to extend the functionality by providing monitoring of failures in asymmetric modes of switching the phases of the engine, two buses are introduced Switching tact and switching parity element, the output of which is connected to the third input of the ZILI-NOT element with gating, information inputs are connected to the outputs of the phase commutator, and parity inputs are connected to the trigger outputs, the installation inputs of which are connected to the buses of the switching speed specification, the counting input is connected to the clock bus and combined with the second input of the one-shot connected to its output with the second input element OR, the output of which is connected to the input gate of the element ZILI-NOT. Switching mode amount included windings Tires Parity inputs of element 13 Control function Item 13 exit 6 7 P1 P2 Symmetric Thu 2- 0 one one 0 Thr 0 ny four-... Is odd one 0 0 one Is odd 0 Unbalanced 1-3-5 -... Odd / Even one one 0/1 1/0 Odd / Even 0 Ricky 1 / 2,3 / 2, 3/4 ...