JPS6018200B2 - Pulse motor control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control method for a pulse motor that allows a target speed to be reached in the shortest possible time without overshooting.

Figure 1 is an electrical circuit diagram of one row of pulse motors in a well-known pulse motor, and Figure 2 shows an example of the relationship between the phase switching timing/pulse train and the drive current flowing through each phase winding in the pulse motor. It is a diagram.

In FIG. 1, 11A to 11D are transistors;
21A to 21D are excitation windings, 3 is a phase switching circuit, PT
indicate phase switching timing pulse trains, respectively.

As shown in FIG. 2, it is assumed that the pulse motor starts running at the first phase switching timing pulse. 1st
When the th phase switching timing pulse is input, the phase switching circuit 3 turns on the transistors 11A and 11B.
When the second phase switching timing pulse is input,
The phase switching circuit 3 turns off the transistor 1-A and turns on the transistor 1-C. When the third phase switching timing pulse is input, the phase switching circuit 3 turns off the transistor 1-B and turns on the transistor 1-D.
When the fourth phase switching timing pulse is input,
The power switching circuit 3 turns off the transistor 1-C and turns on the transistor 1-A. Thereafter, every time a phase switching timing pulse is input to the same machine, the phase switching circuit 3 switches the drive currents flowing through the windings 2-A, 2-B, double threads C, and 2-D. There are various control methods to smoothly accelerate to the target speed in a short time, but in the case of a pulse motor, there is a control method that gradually changes the phase switching timing and pulse interval. Common.

However, when there are multiple target speeds, it is difficult to optimize for each target speed, and it is difficult to optimize for each target speed. Either. The speed characteristics of a pulse motor at startup are:
It depends on the load, motor characteristics, and drive method (drive current and phase switching cycle). In the case of the same load and the same motor, the phase switching timing has a large effect. In Fig. 4, ■ is the speed characteristic when using a phase switching timing pulse train in which phase switching is performed rapidly as shown in Fig. 3 A, and ■ is the speed when using the optimal phase switching timing pulse train. Characteristics (■) indicate speed characteristics when a phase switching timing pulse train in which phase switching is performed slowly as shown in the opening of FIG. 3 is used. Next, a case where a plurality of target speeds are set will be explained with reference to FIG.

If the same phase switching timing pulse train is used for the target speeds S, S2, and S3, a problem will occur when accelerating to any of the target speeds. FIG. 5 shows the target speed S,
This shows an example in which overshoot occurs when accelerating to the target speeds S2 and S3 because a phase switching pulse optimized for the two speeds is shared. The present invention is based on the above considerations, and aims to provide a pulse motor control method that is capable of finding drive methods optimized for each of a plurality of target speeds.

Therefore, the pulse motor control method of the present invention is as follows:
A pulse motor, a phase switching circuit that switches the current flowing through each phase of the pulse motor every time a phase switching timing pulse is input, and multiple types of acceleration slew data strings and multiple types of deceleration slew data. a memory means for storing the column, a microprocessor, a slew data is set as an initial value, and each time a clock is applied, a count value is updated by a unit amount, and when the count value reaches a predetermined value. a slewing circuit that supplies a phase switching timing pulse to the phase switching circuit and interrupts the microprocessor, and when the microprocessor receives an interrupt from the slewing circuit, The next slewing data belonging to the slewing data string that has been selected is retrieved from the storage means and set in the upper slewing circuit, and the i-th acceleration slewing data string is It is a sequence of optimized acceleration slewing data for accelerating the pulse motor to speed S, and the i-th
The th acceleration slewing data string is an optimized deceleration slewing data sequence for decelerating the pulse motor from the speed Sj. Hereinafter, the present invention will be explained with reference to the drawings. FIG. 6 is a block diagram of one embodiment of the present invention,
4 is a pulse motor, 5 is R where a control program is stored.
OM, 6-1 is not provided, 6-3 is a ROM in which a slewing data string for acceleration is stored, 7-1 to 7-3 are ROMs in which a slewing data string for deceleration is stored, and 8 is a microprocessor. , 9 indicates an output port, and 10 indicates a slewing circuit, respectively. Note that 3 is a phase switching circuit as in FIG. 1. ROM5 stores a control program, ROM6-1 stores acceleration slewing data for the target speed S, ROM6-2 stores acceleration slewing data for the target speed S2, and ROM6-3 stores acceleration slewing data for the target speed S2. slewing data for acceleration with respect to the target speed S3 is stored in ROM7-1, and the speed S
, slewing data for stopping from speed S2 is stored in ROM7-2, slewing data for stopping from speed S3 is stored in ROM7-3. is stored.

Microp. Setsa 8 is for starting a pulse motor.
The pulse motor starting processing routine of the control program is executed, and in the case of stopping, the pulse motor starting processing routine of the control program is executed. When starting or stopping the pulse motor 1, ROM6-1, 6-2, 6-3, 7-1,
The slewing data in 7-2 or 7-3 is sequentially read out and set in the slewing circuit 10 through the output port 9. The table below shows one column of slewing data retrieved from ROM. Note that the numbers in the table are in 16 Hayabusa format. The slewing circuit 10 is a counter, and slewing data sent from the output port 9 is set as an initial value.

A clock is applied to the slewing circuit 10', and the count value is incremented by 113 each time the clock is input.

Carry when the counter value reaches a predetermined value, for example "FF".
is output from the slewing circuit 10. This carry pulse is a phase switching timing pulse. On the other hand, the phase switching timing pulse is also used as an interrupt signal to the microprocessor 8. When the microprocessor 8 receives the interrupt, it reads the next slewing data and transfers it to the slewing circuit 101. Now, the acceleration slewing data in the table above is R
Assume that the speed is stored in the OM6-1 and is accelerated to the target speed S.

When accelerating to the target speed S, ROM 6-1 is selected, and slewing data "0" is first set in the slewing circuit 1. When a start command is issued,
A clock is applied to the slewing circuit 101, and its counter value is incremented by 1 every time the clock is input. When the counter value of the slewing circuit 10 reaches a predetermined value, one phase switching timing pulse is sent to the phase switching circuit 3,
At the same time, an interrupt is applied to the microprocessor 8. When interrupted, the microprocessor 8
The slewing data "3" of the next address in the OM 6-1 is set in the slewing circuit 10. When the second phase switching timing pulse is output from the slewing circuit 10, the slewing circuit 10 receives the slewing data "55".
'' is set. When the 15th phase switching timing pulse is generated by repeating the same operation, the slewing circuit 10 receives the slewing data “A2''.
is set, and from now on the passing data “A2”
A phase switching timing pulse is generated at a period determined by '. FIG. 7 shows the speed characteristics of the pulse motor control method according to the present invention.

As can be seen from Fig. 7, in any case, when accelerating to the target speed S, when accelerating to the target speed S2, or when accelerating to the target speed S3, there is no overshoot and in the shortest possible time. It is possible to reach the target speed. Further, although the speed characteristics in the case of stopping are not shown, according to the present invention, the pulse motor can be stopped in the shortest possible time.

[Brief explanation of drawings]

Fig. 1 is an electric circuit diagram of one row of stators in a known pulse motor; Fig. 2 is a diagram showing an example of the relationship between the phase switching timing/pulse train and the drive current flowing through each phase winding in the pulse motor; Figure 3 is a diagram showing an example of phase switching timing and pulse train when starting a pulse motor, Figure 4 is a diagram showing an example of speed characteristics when starting a pulse motor, and Figure 5 is a diagram showing an example of phase switching timing and pulse train when starting a pulse motor. Fig. 6 is a block diagram of one embodiment of the present invention, and Fig. 7 is a control of the pulse motor according to the present invention. It is a figure showing the speed characteristic in a method. 1-A or 1-B...transistor, 2-A or 2
-B... Excitation winding, 3... Phase switching circuit, 4... Pulse motor, 5... ROM for storing control programs, 6-1 to 6-3... ...ROM for storing acceleration slewing data, 7-1 or 7-
3...ROM for storing slewing data for deceleration, 8...Microprocessor, 9...
・Output boat, 10...Slewing circuit. 2 diagrams, 2 diagrams, 4 diagrams;

Claims (1)

[Claims] 1. A pulse motor, a phase switching circuit that switches the current flowing through each phase of the pulse motor every time a phase switching timing pulse is input, and multiple types of acceleration slewing circuits.
A storage means for storing a data string and a plurality of types of deceleration slewing data strings, a microprocessor, and a microprocessor that sets the slewing data as an initial value and calculates a count value by a unit amount each time a clock is applied. a slewing circuit that supplies a phase switching timing pulse to the phase switching circuit and interrupts the microprocessor when the counted value reaches a predetermined value;
Further, when the microprocessor receives an interrupt from the slewing circuit, the microprocessor reads the next slewing data belonging to the specified slewing data string from the storage means and sets it in the slewing circuit. The i-th acceleration slewing data string is a sequence of acceleration slewing data optimized for accelerating the pulse motor to speed S_1,
A control method for a pulse motor, wherein the j-th acceleration slewing data string is an optimized deceleration slewing data sequence for decelerating the pulse motor from speed S_3.