CN2617079Y

CN2617079Y - Step-by-step motor controller

Info

Publication number: CN2617079Y
Application number: CN 03256648
Authority: CN
Inventors: 何伟斌
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-05-01
Filing date: 2003-05-01
Publication date: 2004-05-19
Anticipated expiration: 2013-05-01

Abstract

The utility model relates to a stepper motor controller to drive stepper motor, comprising a CPU, a counter, a timer; the counter counts the input pulses which is corresponding to the positive and reverse turning; the timer provides a wide range of time constants; the CPU which is according to the count of the counter in the timer interrupt service gradually increases or decreases the delay time constant, regulates the output pulses. The drive circuit is a constant current chopper drive circuit. The utility model has the advantages of making the stepper motor rotate smoothly, drive a big rotational torque, guaranteeing the stepper motor not lost step, and improving the power utilization and control speed.

Description

Controllor for step-by-step motor

Technical field

The utility model relates to controllor for step-by-step motor, particularly, and the three-phase and four-line controllor for step-by-step motor of numerically controlled wire cutting machine.

Background technology

In the prior art, numerically controlled wire cutting machine is extensive use of stepping motor, particularly the three-phase and four-line stepping motor is as controlled driving power, adopt current-limiting resistance in its drive circuit, when its supply power voltage is 24V, when phase current was 2-3A, there was waste of electric energy in every power consumption that 48W--70W is arranged approximately when working mutually on this current-limiting resistance.Secondly, come its pulse period of signal of self-controller to alter a great deal, in order to improve control precision, the assurance stepping motor is not lost the step, and drive circuit will provide enough big power headroom and limit running frequency at reduced levels, thereby makes motor torque very little.Moreover, in the constant current chopper circuit of prior art, each phase winding of stepping motor can not be connected into has common port, gives the repacking of wire cutting machine tool driving power like this and upgrade to involve the whole winding joints of motor, thereby make troubles, be not suitable for using the three-phase four-wire system stepping motor.

The technical problems to be solved in the utility model provides a kind of controllor for step-by-step motor, comprise stepper motor driving circuit, its overcome exist in the prior art must make running frequency be limited in reduced levels for improving control precision, thereby make shortcomings such as torque is little, its controller output pulse period is done gradually long or gradually short the variation according to the cycle of input pulse, and it is level and smooth that motor is rotated, driving moment is big, do not lose the step, improve the power utilization rate, improve control rate.

Summary of the invention

For reaching above purpose, the technical solution of the utility model is:

A kind of controllor for step-by-step motor, comprise stepper motor driving circuit, it is characterized in that described controller comprises CPU, counter, timer, described cpu signal input is connected with pulse signal source, output is connected with drive circuit, and described counter is counted the input pulse corresponding to positive and reverse steering; Described timer is in CPU inside, and it provides multiple time constant, and CPU counting according to above-mentioned counter in the break in service work of timer increases, subtracts the delay time constant step by step, regulating impulse output.

According to a kind of controllor for step-by-step motor on the other hand of the present utility model, comprise stepper motor driving circuit, described drive circuit is the constant current chopper drive circuit, described constant current chopper drive circuit is a plurality of identical independent circuits, the number of phases of its number and stepping motor is consistent, each drive circuit is by the independently power supply power supply mutually of same number, and each phase winding of stepping motor inserts in the power amplifier of a described drive circuit, and one of each winding termination of stepping motor is connected to each other together.

Effect of the present utility model is to export to constant current chopper after the pulse via controller of input is handled to drive the three-phase and four-line stepping motor, makes the rotation of stepping motor level and smooth, and driving moment is big, and the assurance stepping motor is not lost the step, improves the power utilization rate, improves control rate.

Description of drawings

Fig. 1 is the circuit diagram of the utility model embodiment.

Fig. 2 is the master control workflow diagram of the utility model embodiment middle controller.

Fig. 3 is interruption, the services flow chart of the utility model embodiment middle controller.

Embodiment

Describe embodiment in detail below with reference to accompanying drawing.

Fig. 1 is the utility model controller embodiment physical circuit figure, comprises stepper motor driving circuit in this circuit diagram.Drive circuit drives the three-phase and four-line reaction stepping motor in this example, comprises three independently identical UA such as voltage source such as grade, UB, UC, gives three separate constant current chopper drive circuitry.These three groups of power supplys are not established common junction, export about 24V.LA, LB, LC are three groups of phase windings of stepping motor, because chopper circuit is independent mutually, do not have the tie point of electricity, so stepping motor can have common junction O, are applicable to the three-phase four-wire system stepping motor.

Be the work of example explanation copped wave drive circuit with control step motor A phase winding LA below: the copped wave drive circuit comprises the current detecting and the control circuit of power amplifier, control circuit, power amplifier is connected in series by second switch pipe QA2, stepping motor one phase winding LA, the first switching tube QA1 and current sampling resistor RA1 and forms the leakage resistance of not limiting.And current detecting and control circuit comprise: make voltage ratio by the Shi Mite circuit that operational amplifier ICA2 and RA9 form, and make current detecting and output control signal, ICA1 is an AND circuit, and QA3 is the prestage of second switch pipe.The concrete course of work is as follows:

The first switching tube QA1 can manage with Darlington transistor or VMOS, second switch pipe QA2 is the Darlington transistor of PNP, DA2 is a fly-wheel diode, the electric energy that DA1 discharges coil when QA1 closes reclaims to the power supply discharge, RA1 is a current sampling resistor, RAW is the current settings potentiometer, and ICA2 and resistance R A9 constitute the Shi Mite circuit.When photocoupler 0A1 no signal, its receiving tube is an open-circuit condition, and switching tube QA1 does not have forward bias and closes, with the P2 pin of door ic chip A1 be low level, the P3 pin is output as low level, QA3 is operated in cut-off region, QA2 also is operated in cut-off region.Therefore there is not electric current among the coil LA.When OA1 had input, its receiving tube was a conducting state, and the P2 pin of ICA1 is a high level, and switching tube QA1 obtains forward bias current, the QA1 conducting.During the firm conducting of QA1, sample resistance RA1 voltage is 0V, and the integrated P3 pin of operational amplifier ICA2 has been connected to setting voltage, the P3 pin is higher than P2 pin level, P1 pin output high level, and promptly the P1 pin of ICA1 is high, the P2 pin has been high, thereby P3 pin output high level, and QA3 obtains positive bias and conducting, QA2 is conducting also, the LA coil current rises, and the last electric current of RA1 rises, simultaneously, the P2 pin current potential of integrated ICA2 rises, when P2 pin current potential is higher than the P3 pin, the upset of Shi Mite circuit, P1 pin output low level, P3 pin output low level with door ICA1 integrated package, QA3 ends, and QA2 also ends, after ending, the magnetic energy that has had among the motor coil L A passes through DA2, LA and QA1 continue discharge and afterflow, electric current begins to descend, and the sampling current potential descends, and promptly ICA2 integrated package P2 pin current potential descends, when being lower than P3 pin current potential, the upset of Shi Mite circuit, the QA2 conducting, power supply is powered to LA again, go round and begin again, finish the process that constant current chopper drives like this.When OA1 did not have input signal, QA1, QA2 closed, and the magnetic energy in the coil reclaims to the power supply discharge by DA2 and DA1.The LA winding drive circuit has independent current source, input signal is isolated, thereby does not have common junction with LB winding drive circuit and LC winding drive circuit, isolates mutually, therefore three-circuit get each winding an end as the common junction end, the work of entire circuit is not influenced.

The work of description control device now.

Three-phase signal A, the B of clock, C import CPU, its pulse period of this signal is changeable, in CPU, establish tape symbol counter D counting is given in this pulse, and open timer at CPU, timer is established many grades of delay time constants, and delay time is established 16 grades from long to short in this example, the time constant pointer is got 0-15, and the delay time constant is got between the 0.02S-0.7MS.The main program intercourse is according to the selected delay time constant of the value of counter D, the pulse of output three-phase six-beat, unison counter D reverse count.When counter D absolute value equals pointer value, pointer is constant, and selected time constant is constant.When the counting absolute value of pointer value greater than counter D, pointer value is subtracted 1, increase time constant and slow down output speed, otherwise, when pointer value during, pointer value is added 1 less than the counting absolute value, reduce time constant and accelerate output.Like this, stepping motor is 50-1428HZ with the operating frequency, gradually quickens step by step or decrescence speed rotation with the speed of input pulse, and stability of rotation is not lost the step.

The workflow of cpu controller is seen Fig. 2,3.

Fig. 2 represents CPU main program control flow, and Fig. 3 represents that its timer interrupts, the service routine flow process.

Referring to Fig. 2, CPU judges whether to exist A, B, C signal (S1) whether to have turn signal (S2), judges its forward and backward (S3), when just changeing, and pulse of every input, counter adds 1, and starts timer, and jumps to the S1 program of carrying out.During counter-rotating, counter subtracts 1 and start timer, and jumps to the S1 program of carrying out.

Interrupt, service routine be the CPU timer then, interrupt main program, the outage service routine, its course of work flow chart is seen Fig. 3.At first CPU judges that when the count value of counter D is zero (S10), expression does not have input pulse, and program is returned main program.Otherwise relatively there are three kinds of situations in the pointer of time-delay setting and the absolute value (S20) of count value, when equating, pointer is constant, and pointer value hour should be accelerated output, and pointer adds 1 (S201), when pointer value was big, then opposite, pointer subtracted 1, with the output speed that slows down (S202).Subsequently by the selected delay time constant (S30) of pointer value, CPU judges the positive and negative of count value, promptly judges to turn to positive and negative (S40), when count value is that one of timing output is rotated in the forward pulse signal, the count value of counter D is subtracted 1 (S41), return main program then.After judgement turns to when negative, export an anti-rotational pulse signal, on its negative counting, add 1 (S42), return main program then.

At any time follow the tracks of input signal with suitable speed through output pulse after the above process, stepping motor guarantees machining accuracy gradually to quicken step by step or decrescence fast stablize, smoothly rotate.

The action of button K1, K2 detects by CPU, and is effective when no A, B, C pulse input, this moment, turn signal was gradually quickened in output, for example: from 500HZ to 10000HZ along or contrary (just or instead) three-phase six-beat signal, change the fast moving work top soon for stepping motor.

Claims

1, a kind of controllor for step-by-step motor, comprise stepper motor driving circuit, it is characterized in that described controller comprises CPU, counter, timer, described cpu signal input is connected with pulse signal source, output is connected with drive circuit, and described counter is counted the input pulse corresponding to positive and reverse steering; Described timer is in CPU inside, and it provides multiple time constant, and CPU counting according to above-mentioned counter in the break in service work of timer increases, subtracts the delay time constant step by step, regulating impulse output.

2, controller according to claim 1, it is characterized in that described multiple time constant arranges from long to short, and give corresponding pointer value from small to large, the count value of described counter is corresponding to the pulse difference of input and output, the more described pointer value of CPU is big or little to the count value of counter, selects to subtract or increase described pointer value.

3, controller according to claim 1 and 2, it is characterized in that described drive circuit is the constant current chopper drive circuit, described constant current chopper drive circuit is a plurality of identical independent circuits, the number of phases of its number and stepping motor is consistent, each drive circuit is by the independently power supply power supply mutually of same number, each phase winding of stepping motor inserts in the power amplifier of a described drive circuit, and one of each winding termination of stepping motor is connected to each other together.

4, controller according to claim 3 is characterized in that: described stepping motor is a phase reaction formula stepping motor, and lead-out wire is a three-phase and four-line.

5, controller according to claim 3, current detecting and control circuit in the described constant current chopper drive circuit of its feature, comprise that the Shi Mite circuit that is made of operational amplifier makes voltage comparator, and AND circuit, two inputs of described voltage comparator are imported the sampling voltage of expression winding current and the voltage that presets that current value is set in expression respectively.

6, controller according to claim 3 is characterized in that: the power amplifier in the described constant current chopper drive circuit comprises first (QA1) and second (QA2) switching tube, and a sample resistance (RA1) and a phase winding (LA) are composed in series.