JPH10174495A - Method of controlling acceleration and deceleration drive of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To see that there is no error with accuracy, according to its pattern, in pulse rate by integrating the function of the pattern by the time when it is shown by the speed control pattern of the function of the time, and computing the quantity of drive for every drive unit time, and subtracting the integrated value of the pulse rate per drive unit time up to now from it. SOLUTION: CPU 3 outputs drive pulses and signals in rotational direction to a sequencer 7 through an output port 6, according to the input of the quantity of input, and a drive circuit 8 controls the switching of the excitation of a motor 9. CPU3 computes the speed control pattern which gives the pulse rate as the function of the time, according to the input of the quantity of shifting from an input part 1. Next, the pulse rate is set (drive a motor) by integrating the pattern by the time, and the integrated value (quantity of drive) of the pulse rate up to now is subtracted from the planned quantity of drive at the time for every drive time of acceleration and deceleration, so as to compute the pulse rate for every unit time and perform acceleration/deceleration drive/ braking. Consequently this can perform the output of the drive pulses in accord with the pattern with accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control method for a motor, and more particularly, to an acceleration / deceleration drive in which a motor is started from a low pulse rate, sequentially accelerated, continued at a constant speed depending on the amount of drive, and then sequentially decelerated. The present invention relates to a control method of acceleration / deceleration drive for driving by a given drive amount.

[0002]

2. Description of the Related Art When a motor is accelerated / decelerated and position-controlled by a drive amount (the number of drive pulses) given by a movement amount of a driven body to be moved by a motor, an acceleration drive time and a constant speed drive are required. In some cases, the sum of the pulse rates obtained for each drive unit time, such as the constant speed drive time and the deceleration drive time, may cause an error with respect to the given drive amount.

In order to reduce the error or eliminate the error, conventionally, it has been checked whether or not each target position has been reached at each required time during the acceleration / deceleration control without relying only on the acceleration / deceleration control. At each required time, the acceleration / deceleration control is corrected based on the check result.
JP-A-6-141594 discloses that when converting the pulse rate to an integer, the remainder after the decimal point is truncated, the remainder is sequentially integrated for each drive unit time, and 1 is added from the integrated value every time the integrated value becomes 1 or more. A method of subtracting and adding 1 to the pulse rate of each drive unit time at that time and outputting the result is disclosed (FIG. 5A). FIGS. 5A and 5B are graphs showing the conventional correction of the driving amount, and the hatched portions in FIG. 5 indicate the correction of the pulse rate.

In Japanese Patent Application Laid-Open No. Hei 5-219797, the number of correction pulses for correcting an error is determined in advance, and the number of correction pulses is divided into two to obtain correction pulses during acceleration and deceleration. A control method is disclosed in which driving at a pulse rate corresponding to the number is performed twice, for example (FIG. 5B).

[0005]

However, conventionally, when a speed control pattern representing a pulse rate for moving a motor by a driving amount (the number of driving pulses) as a function of time is given, the speed is accurately calculated. A method of setting the pulse rate according to the control pattern has not been considered. For this reason, particularly when the motor is accelerated / decelerated in a curved line, the speed control pattern can be obtained, but the speed control pattern is accurately followed, and the sum of the pulse rates for each drive unit time and the drive amount (drive pulse) It is difficult to determine the pulse rate for each drive unit time so as not to produce an error with (number).

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such a problem, and to accurately solve the problem according to a given speed control pattern.
It is another object of the present invention to provide a method for determining a pulse rate for each drive unit time so that an error between the total pulse rate for each drive unit time and the drive amount (the number of drive pulses) does not occur.

[0007]

According to the present invention, to solve the above-mentioned problem, according to the present invention, the motor is accelerated / decelerated by setting a pulse rate for each unit driving time of the motor by calculation in accordance with a given driving amount. When a speed control pattern representing the pulse rate as a function of time is given in the acceleration / deceleration drive control method for a motor, a function obtained by integrating the function of the speed control pattern with time is obtained, and each drive is obtained from the obtained function. The pulse rate for each drive unit time is obtained by calculating the drive amount to be driven for each unit time, and subtracting the integrated value of the pulse rate for each drive unit time up to the present from this drive amount. It is characterized by the following.

The driving unit time is an acceleration driving time,
Each is provided for a constant speed drive time or a deceleration drive time. According to the present invention, the amount of driving (the number of driving pulses) to be driven by the motor during each of the acceleration, constant speed, and deceleration driving times of the motor is clear, so that the motor is driven during each driving unit time. The error between the power to be driven (the number of drive pulses) and the actual drive amount (the number of drive pulses) delayed by one drive unit time is less than one pulse, and the pulse rate according to the given speed control pattern can be accurately and without error. Can be set.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a motor drive control system to which a motor acceleration / deceleration drive control method according to the present invention is applied. In FIG. 1, reference numeral 1 denotes an input unit 1 including an input board and the like. 2 is a control unit, C
It has a PU 3, a ROM 4, a RAM 5, an output port 6, and the like. 7 is a drive pulse from the output port 6 of the control unit 2,
A sequencer 8 that receives a control signal such as a rotation direction and the like is a drive circuit that drives and controls a motor 9 based on the output of the sequencer.

A target position or a moving distance, etc., for movement of a driven body (not shown) driven by driving a motor (for example, a stepping motor) 9 is input to the control unit 2 from the input unit 1 of the drive control system. The control unit 2 includes a CPU (central processing unit) 3 including a microprocessor, a ROM (read only memory) 4, a RAM (random access memory).
5 and an output port 6. ROM4 has CP
Fixed data necessary for control such as a control program of U3 is stored, and the RAM 5 is used as a work area of the CPU 3.

The CPU 3 executes a control program in the ROM 4 and controls the driving of the motor 9 in accordance with the amount of movement inputted numerically from the input unit 1. In this case, the CPU 3 outputs a drive pulse and a signal in the rotation direction to the sequencer 7 via the output port 6, and the excitation of the motor 9 by the drive circuit 8 is switched by the sequencer 7 according to the signal, and the motor 9
Is driven.

Next, the principle of the acceleration / deceleration drive control of the motor by the CPU will be described. FIG. 3 is a graph showing a speed control pattern, and FIG. 4 is a graph showing a function obtained by integrating the speed control pattern with time. In response to an input (movement amount) from the input unit 1, the CPU 3 firstly provides a speed control pattern p for giving a pulse rate as a function of time t as shown in FIG.
(T) is obtained by calculation.

Next, as shown in FIG. 4, a function P (t) obtained by integrating the speed control pattern with time t is obtained by calculation. The drive amount to be driven at that time from the function P (t) for each drive unit time in the acceleration or deceleration drive time, with the time when the pulse rate is started to be set (the motor starts to be driven) set to 0. (Number of drive pulses)
Is calculated, and the pulse rate for each unit time is calculated by subtracting the integrated value of the pulse rate (drive amount up to the present) from this drive amount to each drive unit time up to the present.

Next, the processing procedure of the acceleration / deceleration control by the CPU will be described in detail. FIG. 2 is a flowchart illustrating a processing procedure of the acceleration / deceleration drive control according to the embodiment. CPU3
When performing acceleration / deceleration driving of the motor 9, first, a numerical value of the movement amount of the driven body is input from the input unit 1 (step S).
101). Next, a speed control pattern p (t) corresponding to the driving amount of the motor 9 corresponding to the input moving amount is obtained (step S102).

Next, the above speed control pattern function p
A function P (t) obtained by integrating (t) with time t is obtained (step S103). From the obtained function P (t), a drive amount (number of pulses) at which the motor should be driven in each drive unit time is calculated (step S104). Specifically, assuming that the time in a certain drive unit time is tn, the drive amount to be driven is P (tn).

The pulse rate in the drive unit time is calculated by subtracting the integrated value S of the pulse rate output up to the present time from the drive amount P (tn) (step S105). That is, the pulse rate in the drive unit time is P (tn) -S. Next, the calculated pulse rate for each drive unit time is output (step S106).

Next, the pulse rate is added to the pulse rate integrated value S (step S107). Then, in step S108, it is determined whether or not the acceleration and deceleration driving has ended, and if not, the process returns to step S104. Step S10 for each drive time of acceleration or deceleration
By repeating the processing of the loop from 4 to S108, a pulse rate is output for each drive unit time and acceleration / deceleration drive control is performed.

In this manner, the driving by the amount to be driven is completed, and the acceleration / deceleration driving is completed. It is needless to say that the present invention is not limited to the acceleration / deceleration drive control, but can also be applied to a case where the control is carried out in addition to the constant speed drive control. According to the method of the present embodiment as described above, the driving amount (the number of driving pulses) to be driven in each driving unit time including the time when the driving is finally completed and the actual driving unit time delay of one driving unit time. The error of the driving amount is less than one pulse, and the driving pulse can be output exactly according to the speed control pattern.

[0019]

As is apparent from the above description, according to the present invention, the motor is controlled by setting the pulse rate for each unit drive time of the motor in accordance with the given drive amount (the number of drive pulses). In the acceleration / deceleration drive method for a motor that drives acceleration / deceleration, when a speed control pattern representing the pulse rate as a function of time is given, the function of the speed control pattern is determined in order to obtain the pulse rate for each drive unit time. Since the function integrated with time is used, the driving amount (the number of driving pulses) to be driven in each driving unit time including the time when the driving is finally completed and the actual driving amount (one driving unit time delay) The error of the number of drive pulses is less than one pulse, and a drive pulse can be output exactly according to the speed control pattern.

In view of the above, when driving a motor that requires high precision, particularly when performing a smooth curved drive (S-shaped acceleration / deceleration), it is complicated to obtain a pulse rate for each drive unit time. A high-speed and accurate pulse rate can be set without requiring a calculation process. Therefore, when performing smooth acceleration / deceleration (S-shaped acceleration / deceleration) of the motor, the pulse rate is accurately set according to the control pattern, so that there is also an effect that the followability of the motor is improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a motor drive control system to which an acceleration / deceleration drive control method according to the present invention is applied;

FIG. 2 is a flowchart illustrating a processing procedure of acceleration / deceleration drive control according to the embodiment;

FIG. 3 is a graph showing a speed control pattern.

FIG. 4 is a graph showing a function obtained by integrating a speed control pattern with time.

FIGS. 5A and 5B are graphs showing a conventional drive amount correction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input part 2 Control part 3 CPU 4 ROM5 RAM 6 Output port 7 Sequencer 8 Drive circuit 9 Motor

Claims (2)

[Claims] 1. A motor acceleration / deceleration drive control method for setting a pulse rate for each unit drive time of a motor in accordance with a given drive amount by calculation and driving the motor in an acceleration / deceleration manner, wherein the pulse rate is a function of time. A motor acceleration / deceleration drive control method characterized by using a function obtained by integrating a function of the speed control pattern with time in order to obtain a pulse rate for each drive unit time, when a speed control pattern represented by 2. A function obtained by integrating a function of the speed control pattern with respect to time is calculated, a driving amount to be driven for each driving unit time is calculated from the obtained function, and each driving amount from this driving amount to the present is calculated. 2. The motor acceleration / deceleration drive control method according to claim 1, wherein the pulse rate for each drive unit time is obtained by subtracting the integrated value of the pulse rate for each unit time.