JPS6014598B2 - Pulse motor phase advance control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phase advance control method for pulse motors, and more particularly to a phase advance control method using a microprocessor for controlling two pulse motors using a 1-2 phase excitation method. It is something.

For example, in a serial printer, a print head 1 is mounted on a carriage 41 fixed to a wire 3 connected to a feed pulse motor 2, as shown in FIG. While stopping and printing, the recording paper 5 is fed by a paper feed pulse motor 6 every time printing for one line is completed.

In this way, in a device equipped with two motors such as a printer, it is necessary to independently control the rotational phase of these motors. As shown, the phase is advanced by microprocessor program control.

There are four phase advance control methods for 4-phase pulse motors, including 1-phase excitation, 2-phase excitation, 1-2-phase excitation, and double 1-2-phase excitation. is a 1-2 phase excitation type. In the subordinate phase advance control method shown in FIG.
A table showing the phase advance pattern for motor B is stored, and the microprocessor sequentially reads pattern data from the table according to a program, and
By setting 4 bits (input through 27) in the latch circuit 8 for each motor B, the bits are sent to the motors A and B as a control signal. However, since this method uses a table to create a phase advance pattern, it requires operations such as referencing the table and updating index registers to pull the table, which requires processing within the microprocessor. It takes longer.

Furthermore, since the table needs to be stored, the memory capacity increases accordingly. An object of the present invention is to eliminate such conventional drawbacks, and to perform phase advance control of two 4-phase pulse motors using a 1-2 phase excitation type, the present invention requires less external hardware and a microprocessor. It is an object of the present invention to provide a phase advance control method for a pulse motor that requires a short processing time for phase advance control and does not require an increase in memory capacity.

The phase advance control method for a pulse motor according to the present invention connects the output of an 8-bit latch circuit so as to directly serve as an excitation signal, and controls two 4-phase pulse motors in a 1-2 phase excitation type. In the phase advance control method of the pulse motor to be controlled, each phase of the two pulse motors is alternately assigned to the output of the 8-bit latch circuit to form a striped line, and the contents of the register of the microprocessor are sequentially read. Create the operating waveform data of 1-2 phase excitation by shifting, and convert the heartbeat waveform data to the above 8.
It is characterized by being set in a bit latch circuit.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a schematic diagram illustrating the principle of the invention.

Recently, in the control of pulse motors, there has been a trend to reduce the number of external TTL elements in order to reduce the amount of hardware, use microprocessor memory in their place, and convert this memory into an LSI to reduce weight. As described above, the simpler the external elements are, the more the burden placed on the processor increases, leading to an increase in the processor's internal processing time and memory capacity. Furthermore, in order to improve the performance of the phase advance control circuit and rotate the pulse motor at high speed, it is necessary to shorten the processing time required for phase advance.
In the present invention, the motor operating waveform data is created by shifting the contents of a register in the microprocessor without using tables, and it is only necessary to set the updated contents of the register in the latch circuit.

In that case, each phase of the motor is alternately assigned to the output of the latch circuit. That is, as shown in FIG. 3, initial phase data is set in registers 1 and 12 corresponding to motors A and B according to instructions from the microprocessor, and is sent to latch circuit 8 via an arithmetic circuit and an accumulator. output to alternately allocated bit positions. In the next cycle, registers 11 and 1 are set by the program.
Since the contents of 2 are shifted, the updated contents are set in the latch circuit 8 as the next operation waveform data. In this way, if you first set the register contents and shift direction using the microprocessor program,
The contents of the registers are sequentially shifted and updated, and the operating waveform data of the two motors A and B are continuously output. The coupling relationship between the latch circuit 8 and each phase of motors A and B is
As is clear from comparing the figure with Figure 3, conventionally, bits 1 to 4 correspond to phases 1 to 4 of motor A, and bits 2 to 2 correspond to phases 1 to 4 of motor B. Whereas in the present invention, bit? . FIG. 4 is a connection configuration diagram of a latch circuit and a motor drive circuit showing an embodiment of the present invention.

The microprocessor 7 connects the pulse motor drive circuit (amplifier ICI~8, /
Power transistor TRI~8, diode DI~8
etc.) and the excitation coils of motors A and B? 1~J4
connected to. When writing to the latch circuit 8, the contents of the accumulator (ACC) are transferred according to an output command defined in the microprocessor 7.

ICI~8 in Figure 4 is an open collector IC
TRI~8 is a power transistor for exciting the motor windings, and DI~8 is a power transistor for exciting the windings ◇1~
This is a diode for looping the flyback current generated when the excitation of J4 is cut off.

FIG. 5 is a time chart showing a phase advancing pulse train of 1-2 phase excitation used in the present invention.

1-2 phase excitation creates a pulse train as shown in Figure 5,
This pulse excites the winding? 1 to J4 to rotate the motor.

The motor is energized at the time of the pulse.

The function of the phase advance control circuit is to control each phase JI to J4 of the two motors.
The purpose is to obtain the instantaneous values "1" and "0" of the pulse train corresponding to the latch output.

FIG. 6 is an operational flow chart of a pulse motor phase advance control system showing an embodiment of the present invention.

In the present invention, registers 11 and 1 for holding the rotational position of each of motors A and B are provided in the microprocessor.
2, and these registers 11 and 12 have the contents "10000011" and "0" shown in FIG. 6b when the power is turned on.
After being initialized to 000011r, it is shifted left and right based on a rotation command. Furthermore, since it is necessary to indirectly access these two registers 11 and 12 depending on the program, the index register 9 and flub 10 shown in FIG. 6b are used. In Fig. 6a, first specify one of the two motors and specify the rotation direction using a separate program, then start this program, create motor drive pulses using this program, and set the latch circuit. Output to 8.

When another program is started and a phase advance motor is designated in step 1, "0" or "1" is set in the index register 9 for designating the motor.

Now, it is assumed that motor A is designated when the value is "0" and motor B is designated when the value is "1".Next, in step 1', the rotation direction of the motor is designated by the programmatic plug 10. For example, when the direction is "0", clockwise rotation is specified, and when "1", counterclockwise rotation is specified.On the other hand, registers 11 and 12 are initialized to the contents shown in FIG. 6b when the power is turned on. Note that register 1
1 makes only the contents corresponding to motor A (value "0001" of bits 〆, 〆, Z, ME) valid, and register 2 makes valid the contents corresponding to motor B (value of bits Z, 0
001”) is valid.

Next, the program jumps to this program, and in step 2, the rotation direction is determined from flag 1.

Since the motor to be rotated is specified by index register 1, the processing is uniform, and when rotating counterclockwise, the motor phase is rotated from ① to ◇◇4.
In step 3, if the contents of the register indicated by the index register 1 are rotated 2 bits to the left (if the register is 0'' then the register 1 is 1, and if the register is 1'' then the register is 12), the contents of the register 1 are ( 0000111, and the contents of register 12 become "0001110").Similarly, when rotating clockwise, the motor phase is rotated from 04 to ◇1, so in step 3', the contents of index register 1 are Rotate register 11 or 12 to the right by 2 bits (the contents of register 11 will be “1”).
1r000o0'' The contents of register 12 are “11000”
00r). This data then remains in the accumulator (ACC) as a result of the shift operation. The contents of the accumulator (ACC) become the next stop position of the specified motor, so in step 4 the accumulator (ACC) is
The contents of C) are stored in register 1 or 12 indicated by index register 1, and the stop position is updated. In step 5, the excitation phase of motor A is determined.

In order to extract only the bit position of the latch circuit 8 connected to the motor A from the contents of the register 11, the contents of the register AII are ANDed with (55) and 6, and this result is temporarily saved outside the register. Store it.

(55), 6=“01010101”, so bits 〆, 〆, 〆, 〉, and their values are set in the save register.
Next, in step 6, the excitation phase of motor B is determined.

In order to extract only the bit position of the latch circuit 8 connected to the motor B from the contents of the register 12, the contents of the register B12 are ANDed with (AA) and 6, and the result of the operation is sent to the accumulator (ACC). Set to . (A
A), 6 = “10101010'', so only the value of bit 27, 0, 0, ? is in the accumulator (ACC)
left behind.

In step 7, the contents of the save register and the accumulator (
ACC) and outputs the result of this operation to the latch circuit 8.

As a result, data corresponding to motor A and motor B are alternately set in the latch circuit 8 and output to each motor drive circuit. With these steps, motor A,
B rotates one step.

By starting this program at regular intervals (periods), continuous rotation of motors A and B becomes possible. As explained above, according to the present invention, all other controls are programmed by simply providing an external general-purpose 8-bit latch circuit, so external hardware is simplified and the program step Since the number is reduced, processing time can be shortened.

In addition, the phase advance can be controlled simply by manipulating the registers in the microprocessor without providing a table for phase advance, so memory capacity is saved, and when using a table An improvement of about 20% is possible compared to .

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a serial printer, Figure 2 is an explanatory diagram of a conventional phase advance control method, Figure 3 is a schematic diagram showing the principle of the phase advance control method of the present invention, and Figure 4 is an illustration of the present invention. A connection configuration diagram of a latch circuit and a motor drive circuit showing an embodiment of the invention,
FIG. 5 is a time chart showing a phase advance pulse train for 1-2 phase excitation used in the present invention, and FIG. 6 is an operation flowchart of a pulse motor phase advance control system showing an embodiment of the present invention. 1: Print head, 2: Head feed pulse motor, 3: Wire, 4: Carriage, 5: Recording paper, 6: Paper feed pulse motor, 7: Microprocessor, 8: Latch circuit, 9: Index register , 10: Flag, 11: Register A, 12: Register B. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. A pulse motor phase advance control system in which the output of an 8-bit latch circuit is directly connected as an excitation signal for the pulse motor, and two 4-phase pulse motors are controlled using a 1-2 phase excitation system. Each phase of the two pulse motors is alternately assigned and connected to the output of the 8-bit latch circuit, and a register is provided to hold each rotational position of the two pulse motors. A phase advance control method for a pulse motor, characterized in that the contents of a register are sequentially shifted 2 bits at a time to create operating waveform data, and then the operating waveform data is output to the 8-bit latch circuit.