JPH02139607A - Position controller for moving body - Google Patents

Abstract

PURPOSE:To considerably shorten the time required for arrival at the final target position of a moving body by stepwise driving a servo motor at a certain speed up to a prescribed set position and driving the servo motor at a speed suitable for the distance to the final target position after arrival at the set position. CONSTITUTION:A position which is a desired length short of the final target position of the moving body is preliminarily set in a data memory 11, and this set position and the position of the moving body obtained by an encoder are compared with each other by a comparator 12, and the servo motor is driven at a prescribed fixed speed until the moving body reaches the set position. The servo motor is driven at a speed corresponding to the deviation between a position command pulse and a position feedback signal from the encoder until the moving body reaches the final target position after arriving at the set position. Thus, the time required for arrival at the final target position of the moving body is considerably shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a position control device for a moving object, and particularly to a position control device for a moving object that can shorten control time.

[Prior art]

As shown in FIG. 4, the conventional position control device for a moving object uses a command pulse train generator 2 to generate position command pulses for a servo motor 1 that drives the moving object as a command pulse train to the final target position of the moving object, and uses this pulse train signal to The position feedback signal from the encoder 3 fixed to the rotating shaft of the servo motor 1 is applied to the position control circuit 4, and the deviation between the two is applied as an analog speed command signal to the speed control circuit 6 via the D/A converter 5. A torque command signal obtained from the deviation from the analog speed signal of the servo motor 1 obtained from the speed calculating section 7 is applied to the sine wave signal generation circuit 8, and a commutation sensor fixed to the rotating shaft of the servo motor 1 The signal from 9 is applied to a sine wave signal generation circuit 8, and the sine wave signal from this sine wave signal generation circuit 8 is applied to the servo motor 1 via a gate circuit 10.

In such a conventional position control device for a moving object, as shown in FIG. The position becomes a stepped line as indicated by the position feedback signal from the encoder 3 (position control).

In this case, the speed command is usually changed in a stepwise manner so as to reach a maximum approximately halfway between the initial position and the final target position, as shown in FIG.

[Problem to be solved by the invention]

As described above, in the conventional position control device for a moving object, it is necessary to set in advance a position command pulse until the moving object reaches the target position, and the processing speed is slow.

The moving body position control device of the present invention is designed to eliminate the above-mentioned drawbacks.

[Means to solve the problem]

The moving body position control device of the present invention includes a mechanism for setting a position of a moving body a desired distance before the final target position, a mechanism for driving the moving body at a constant speed until the moving body reaches the set position, and a mechanism for driving the moving body at a constant speed until the moving body reaches the set position. It is characterized by comprising a mechanism that drives the moving body at a speed corresponding to the distance between the moving body and the final target position until the moving body reaches the final target position.

[Function] According to the moving object position control device of the present invention, the time required to move the moving object to the final target position can be significantly reduced.

〔Example〕

The present invention will be explained in detail below with reference to the drawings.

In the present invention, as shown in FIG.
A position a desired distance ahead of the final target position of the moving body is preset within the camera, and this set position and the position of the moving body obtained from the encoder 3 are compared by a comparator 12, and the servo motor 1 is operated until the moving body reaches the set position. After reaching the set position, the servo motor 1 is driven at a speed corresponding to the deviation between the position command pulse and the position feedback signal from the encoder 3, as before, until the final target position is reached. (position control).

〔Effect of the invention〕

As described above, according to the moving body position control device of the present invention, the second
As shown in the figure, until the set position is reached, the servo motor 1 is driven stepwise at a constant speed (speed control)) After reaching the set position, the servo motor 1 is driven at a speed commensurate with the remaining distance until the final target position is reached (position control ), the time required for the moving object to reach the final target position can be significantly reduced, and there is a great advantage that a pulse train generator is not required.

O...Gate circuit, 11...Data memory, 12.
...Comparator.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a moving body position control device according to the present invention;
Figure 2 is a diagram showing the relationship between the position of a moving body and control time, Figure 3 is a diagram showing the relationship between its velocity and control time, and Figure 4 is a block diagram of a conventional position control device for a moving body. , FIG. 5 is a diagram showing the relationship between the position of the moving object and the control time, and FIG. 6 is a diagram showing the relationship between the speed and the control time.

Claims (1)

[Claims] 1. A mechanism for setting a position a desired distance before the final target position of a moving object, a mechanism for driving the moving object at a constant speed until the moving object reaches the set position, and a mechanism for driving the moving object at a constant speed until the moving object reaches the final target position from the set position. and a mechanism for driving the moving body at a speed corresponding to the distance between the target position and the final target position.