JPS63191210A - Positioning control system for actuator - Google Patents

Abstract

PURPOSE:To accurately position an actuator at its target stopping position regardless of the variance of dimensions among mechanism parts of the actuator or the total error produced by the assembly of the actuator, by deciding the stopping position of the actuator based on a relative position detecting marker. CONSTITUTION:When an actuator 9 is stopped at a desired position, a microcomputer 1 performs a monitor job by means of the relative position detecting markers 8 set at each stop position and a relative position detector of the actuator 9 and decides whether or not the markers 8 are coincident with each desired stop position. When a desired marker 8 is recognized, the microcomputer 1 counts the pulse signals of a pulse encoder 4 connected directly to a miniature motor 3 which are outputted from a forward/reverse pulse discriminating circuit 6 based on the edge of the marker 8. Then the count value of the pulse signals is compared with the number of pulses equivalent to the width of the marker 8. Then the drive of the motor 3 is stopped as soon as the coincidence is obtained from said comparison. Thus the actuator 9 is set at a desired stopping position.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a positioning control system for a motor-driven actuator that moves a plurality of positions +1tl.

(Prior art) The conventional positioning control method for this type of actuator is as follows:
It has the configuration shown in FIG. That is, 11 is a microcomputer that controls and monitors the small motor drive circuit 12 and the reversible counter 15. A small motor 13 is directly connected to a pulse encoder 14 and drives an actuator.

In such a conventional system, the microcomputer 11
transmits a signal to the small motor drive circuit 12 to drive the motor 13
An actuator (not shown) is moved by rotating the . When the actuator is stopped at a target position, a pulse signal output from a pulse encoder 14 directly connected to the motor 13 is integrated by a reversible counter 15 and converted into a count value corresponding to the rotation direction of the motor 13. The microcomputer 11 compares and calculates the accumulated count value with a predetermined count value given to the target stop position, and at the same time when they match, the signal to the small motor drive circuit 12 is cut off to stop the small motor 13, and the actuator Stop 2 and position.

In this way, the microcomputer 11 performs a comparison calculation between the integrated count value of the pulse encoder 14 and a predetermined count value given to the stop position, and controls the drive of the small motor 13 to move the actuator to the desired position. It is used for positioning.

(Problem to be Solved by the Invention) In such conventional systems, the predetermined count values required for each stop position of the actuator are determined and set by calculation, but in reality, variations in mechanical parts and Due to cumulative errors that occur during the assembly of parts, the predetermined count value obtained by calculation and the count value required for the actual stop position are not the same, and vary by several pulses.

Therefore, in order to position at the actual stop position, measure the amount of variation at each stop position, calculate the count value according to the measured value, and calculate the count value of all the stop positions obtained by calculation. There is a problem in that the value must be changed to the value determined by measurement, and the correction cannot be made quickly.

In view of the above points, the present invention has been developed to enable positioning at a desired stop position without being affected by variations in the dimensions of the actuator's mechanical parts or variations in the stop position due to cumulative M errors that occur when assembling these parts. The present invention provides a positioning control method for an actuator.

(Means for Solving the Problems) Therefore, the present invention provides a method in which a relative position detector is attached to an actuator that is moved by the driving force of a motor that rotates and stops in response to command signals from a microcomputer.
A relative position detection marker is provided at each desired stop position of the actuator, and the microcomputer detects the edge of the relative position detection marker when the actuator moves and the relative position detector detects the edge of the relative position detection marker at the desired stop position. The computer starts counting pulse signals from a pulse encoder directly connected to the motor, compares the number of pulses with the number of pulses corresponding to the width of the marker, and stops the motor at the same time when a match is found.

(Function) When the relative position detector attached to the actuator detects the edge of the marker set at the desired stop position, the pulse encoder starts counting the pulse signals, and the computer compares them with the number of pulses corresponding to the width of the marker. Since the motor is stopped when the calculation matches, the actuator can be stopped at the desired position, and even if there are cumulative errors due to assembly of the actuator's mechanical parts, these errors will not affect the actuator at all. First, the actuator can be positioned at the desired position.

(Embodiment) FIG. 1 shows an embodiment of the present invention, in which 1 is a microcomputer, a small motor drive circuit 2. Controls and monitors the forward/reverse pulse discrimination circuit 6 and the relative position detector 6. 3 is a small motor for moving the actuator 9, and a pulse encoder 4 is directly connected thereto. 8 is a relative position detection marker provided at each desired stop position of the actuator 9.

Rotation and stop control of the small motor 3 is performed by the microcomputer 1 transmitting signals to the small motor drive circuit 2.

Therefore, when the actuator 9 is stopped at a desired position, the relative position detection marker 8 attached to each stop position is
The microcomputer 1 monitors this using a relative position detector attached to the actuator 9, and determines whether the relative position detection marker 8 is at the desired stop position. When the target relative position detection marker 8 is recognized, the microcomputer 1 firstly counts the pulse signal of the pulse encoder 4 directly connected to the small motor 3 which is output from the forward/reverse pulse discrimination circuit 6 using the edge of the marker 8 as a reference. , and the number of pulses corresponding to the width of the marker 8, and when they match, the small motor 3 is stopped and the actuator 9 is positioned at the desired stop position.

When changing the stop position of the actuator 9, the mounting position of the relative position detection marker 8 may be changed. The final positioning at the time of stopping is performed by calculating the amount of pulses of a pulse encoder directly connected to the motor, so that the same accuracy of positioning as the resolution of the pulse encoder can be obtained. Furthermore, since the relative position detector is attached to the actuator and the pulse encoder is directly connected to the motor, positioning errors due to the transmission system between the motor and the operating section are reduced.

(Effects of the Invention) As described above, according to the present invention, since the stop position of the actuator is determined based on the relative position detection marker, the cumulative error caused by variations in the dimensions of the actuator's mechanical parts and zero assembly is eliminated. Even if there is a problem, the vehicle can be positioned at the desired stopping position without being affected by this.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a schematic block diagram of a conventional positioning control system for a motor-driven actuator. 1...Microcomputer, 3...Motor, 4
...Pulse encoder, 7. Relative position 11 detector, 8. Relative position detection marker, 9. Actuator.

Claims (1)

[Claims] A relative position detector is attached to an actuator that is moved by the driving force of a motor that rotates and stops in response to a command signal from a microcomputer, and a relative position detection marker is provided at each desired stop position of the actuator. When the actuator moves and the relative position detector detects the edge of the relative position detection marker at the desired stop position, the pulse encoder directly connected to the motor starts counting pulse signals, and the computer starts counting pulse signals for the width of the marker. A positioning control method for an actuator, characterized in that the motor is stopped at the same time when the number of pulses matches the number of pulses.