JPH0315300A - Stepping motor controller - Google Patents

Abstract

PURPOSE:To improve control accuracy by controlling the duration of each exciting phase signal for a plurality of step motors through control means according to the minimum exciting phase duration calculated through an operating means. CONSTITUTION:A maximum settable value is set, as an initial value, in a timer 5. Then judgement is made whether phase duration data are 0, and when the data are zero an exciting phase duration is taken out from a table 4 in order to modify the exciting phase duration data, thereafter next exciting phase signal data are read out from a memory 3 and subjected to operation. Then judgement is made whether the exciting phase duration data are smaller than the minimum duration data, and if the exciting phase duration data are smaller than the minimum duration data, content of the exciting phase duration data are substituted with the minimum duration data. Thereafter, the minimum duration data are subtracted from the exciting phase duration data for each motor.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention provides a method for integrating a plurality of stepping motors into one CPU.
The present invention relates to a control device that controls by.

Conventional technology FIG. 4 shows the structure of this type of control device.

In this system, the rotational speed of the stepping motor 7 is controlled by controlling the holding time of an excitation phase signal that controls the current flowing through the coil in the motor. Note that there are as many elements marked with * in the diagram as there are motors.

The excitation phase signal retention time data memory 2 stores excitation phase signal retention time data. This excitation phase signal retention time data is the time from the start of one pattern of the excitation phase signal to the start of the next pattern.

The excitation phase signal data memory 3 stores excitation phase signal data. This excitation phase signal data is a bift pattern of the excitation phase signal in the next timing, and this bit pattern is fixed by the excitation method of the stepping motor 7.

The excitation phase holding time table 4 stores a column of excitation phase holding time data prepared in advance. The timer 5 is hardware that has a function of notifying the CPU 1 when a set time is reached, and counts the time for switching the excitation phase.

The driver 6 analyzes the excitation phase signal data given from the CPUI, and controls the current supplied to the stepping motor 7 according to this data.

FIG. 5 shows the operating procedure. First, excitation phase signal data is read from the excitation phase signal memory 3 and outputted to the driver 6 (step #1).

Next, the minimum unit time for counting is set in the timer 5, and time counting is started (#2). Next, 1 is subtracted from the excitation phase signal retention time data read from the excitation phase signal retention time data memory 2 (#3). The excitation phase signal holding time data is determined (#4), and when the timer 5 times out when this is not O, the process returns to step #1. When the excitation phase signal holding time data becomes 0, the next excitation phase signal data is read from the excitation phase signal data memory 3, this is adjusted by arithmetic processing (#5), and the next excitation phase holding time data is then set. When the timer 5 completes the time adjustment (#6), the process returns to step #1.

Problems to be Solved by the Invention In the conventional control device described above, when the number of stepping motors controlled by one CPU increases, the minimum unit time cannot be reduced due to internal processing time, and this makes it difficult to increase the speed. It was causing a hindrance. On the other hand, if the number of stepping motors is large and the minimum unit time is small, time will elapse while processing for some motors is not completed, making it impossible to count down. This caused a decrease in control accuracy.

Means for Solving the Problems> The present invention reduces the rotational speed of a plurality of stenoping motors to one
In a stepping motor control device controlled by a CPU, there is provided a control means for controlling the holding time of an excitation phase signal that controls the current flowing through the coil of the stepping motor, and the nearest excitation phase in excitation phase switching processing of each stepping motor. and a calculation means for calculating minimum retention time data quantized in the minimum unit time of the time until switching, and the control means controls the excitation phase signal according to the minimum value of the excitation phase retention time calculated by the calculation means It is characterized by controlling the retention time of

Function> In the stepping motor control device according to the present invention, the control means controls the holding time of the excitation phase signal of each of the plurality of stepping motors according to the minimum value of the excitation phase holding time calculated by the calculation means. It is characterized by

Embodiment FIG. 1 shows the structure of a stepping motor control device according to this embodiment. In the figure, 1 is a CPU, 2 is an excitation phase retention time data memory, 3 is an excitation phase signal data memory, 4 is an excitation phase retention time table, 5 is a timer, and 6
is a driver, 7 is a stepping motor, and 8 is a minimum retention time data memory. The structure is the same as the conventional structure (FIG. 4) except for the minimum retention time data memory 8, and the same elements are given the same reference numerals as in FIG. 4. In addition, there are the same number of elements marked with * in the diagram as there are steering and bing motors.

The minimum retention time data stored in the minimum retention time data memory 8 is data quantized in the minimum unit time of the time until switching of the nearest excitation phase in the excitation phase switching process. FIG. 2 shows the relationship between the change in excitation phase and the minimum holding time data between the two stenoping motors A and B. The minimum time between the switching of the excitation phase of motor A and the switching of the excitation phase of motor B is the minimum holding time.

FIG. 3 shows the processing procedure.

First, the maximum value that can be set in the timer 5 is set as the initial value of the minimum retention time data (step #1). next,
Determine whether the excitation phase holding time data is O (#2), and
When this is the case, the next excitation phase holding time value is taken out from table 4 and the excitation phase holding time data is changed (#3), and the next excitation phase signal data is read out from memory 3 and set by calculation (#4).

Then, it is determined whether the excitation phase retention time data is smaller than the minimum retention time data (#5), and if the excitation phase retention time data is smaller than the minimum retention time data, the content of the excitation phase retention time data is changed to the minimum retention time. Assign to data (#6). When the excitation phase holding time data is not smaller than the minimum holding time data, the minimum holding time data is not changed.

Further, when the determination result in step #2 is not O, the process moves to step #5.

The above processes from step #2 to step #6 are executed for the number of step knocking motors.

After that, the minimum holding time data is subtracted from the excitation phase holding time data of each motor (#7).

After the above processing, when timer 5 time amps (#
8) Output the excitation phase signal data to the driver 6 (#
9). Then, the minimum holding time data is set in the timer 5, the timer is activated, and the process returns to step #2.

Note that the mark * in FIG. 3 indicates that this process is executed for the number of stepping motors.

Effects of the Invention According to the present invention, since the motor control process is performed at the maximum number of times the excitation phase is switched for all motors, the time between switching can be reduced. Therefore, higher speed stepping motors can be achieved. Further, since there is no possibility that the time will be delayed due to a time-out before processing is completed for some motors, deterioration of control accuracy can be prevented. Furthermore, since other processes can be executed at times other than the excitation phase switching process, the system utilization efficiency is improved.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the structure of the embodiment of the present invention, Fig. 2 is a diagram showing signal waveforms of the embodiment of the invention, Fig. 3 is a flowchart showing the processing procedure of the embodiment of the invention, and Fig. 4 is FIG. 5 is a block diagram showing the structure of the conventional example, and FIG. 5 is a flowchart showing the processing procedure of the conventional example. 1 ・ ・ ・ CPU ・Excited phase holding time data memory ・Excited phase signal data memory ・Excited phase holding time table timer driver stepping motor minimum holding time data memory 2nd flash*

Claims (1)

[Claims] The rotational speed of multiple stepping motors can be combined into one CP.
A control device for a stepping motor controlled by U includes a control means for controlling the holding time of an excitation phase signal that controls the current flowing through the coil of the stepping motor, and switching of the nearest excitation phase in excitation phase switching processing of each stepping motor. and calculation means for calculating the minimum retention time data quantized in the minimum unit time of the time,
A control device for a stepping motor, wherein the control means controls the holding time of the excitation phase signal in accordance with the minimum value of the excitation phase holding time calculated by the calculation means.