JP2703844B2 - Computer for digital control - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital control calculator for giving a control command to an actuator to be controlled such that a physical quantity such as a position and a speed of the actuator coincides with a target value.

[0002]

2. Description of the Related Art FIG. 5 is a timing chart showing a processing execution means of a conventional digital control computer shown in, for example, "Introduction to Programmable Controllers in the Field" (issued by Ohmsha on July 30, 1986). The processing steps a to c are repeatedly performed for each sampling cycle. In each sampling cycle, a is an input processing step of inputting a control amount of the actuator to be controlled, b is a control operation step of calculating a control command for the actuator based on the current value of the control amount obtained in the input processing step a, c is This is an output processing step of outputting the control command calculated in the control calculation step b to the actuator.

Hereinafter, the operation of the conventional apparatus will be described with reference to FIG. First, in the input processing unit step, the control amount detected at the scan timing 10 is regarded as the current value and input processing is performed. Next, scan timing 5
When it becomes 0, an error which is a difference between the current value and the target value of the control amount obtained in the input processing step a is calculated in the control calculation step b. In the output processing step c using this calculated value, a control command is obtained at the scan timing 150 according to the control law, and this is output to the actuator.

As described above, the data input / output processing steps a to c are completed in one sampling cycle.
At the same scan timing in the next sampling cycle, data input processing, arithmetic processing, and output processing are sequentially performed, and each processing in one sampling cycle ends.

[0005]

In the conventional digital control computing device, since each data processing is fixed at each scan timing during each sampling cycle, the amount of control data taken in the input processing is reduced. Accordingly, there is a problem that the scan timing of the next process is shifted, for example, when data processing is started from a position after the scan timing 150, the output timing to the actuator is shifted to the scan timing of the next sampling cycle.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and a digital processing system capable of arranging and completing an output processing step such as a stop command to an actuator at an arbitrary position within one sampling period. The purpose is to obtain a control computing device.

[0007]

A computing device for digital control according to the present invention arithmetically processes input-processed data to generate a control command for a control target, outputs the control command to the control target, and outputs the control command to the control target. a program execution unit for executing the output processing of the control command in dependence on control data volume versus untreated emissions <br/> grayed determines whether delayed until the next sampling period taken by, when the slippage is determined, An estimating means for estimating from which control position the control command is to be output at which timing position in the next sampling period based on a control amount for the control target, and a movement command for moving the control command output process to the estimated timing position. Moving means for outputting to the program execution unit, and in response to the movement command, the program execution unit executes a process of outputting the control command to the next sampler. It is intended to run on the determined timing position in period.

[0008]

According to the present invention, there is provided a digital control computing device comprising:
The control unit predicts and calculates at which scan timing within the sampling period the control command should be output to the control target by the estimating means, and outputs the control command at the predicted calculated scan timing. The time lag of the control command output over a maximum of one sampling cycle depending on the amount of data is eliminated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing a controlled object controlled by a digital control computing device according to an embodiment of the present invention. In the drawing, reference numeral 1 denotes a stepped sleeve that has been inserted into a shaft (mandrel) of a steel plate winding device (not shown), 2 denotes a step portion of the stepped sleeve 1, and 3 denotes a steel plate wound around the stepped sleeve 1.

In this case, the control purpose of the digital control computing device is to rotate the stepped sleeve 1 clockwise from the state shown in FIG. At a fixed position at the tip end position (angle θ ₁ ) of the steel plate 3.

The procedure for executing the position control process will be described with reference to the timing chart of FIG. In the figure, A is an input processing step in which current rotation angle data from a rotation angle detector (not shown) of the stepped sleeve 1 is loaded into a memory in the computer. B is input processing step A
Is a control operation step of calculating a speed command of a motor which is an actuator of the stepped sleeve 1 based on the rotation angle data taken in step C; and C is an output processing step of outputting the speed command calculated in the control calculation step B to the actuator. It is.

FIG. 3 is a functional block diagram showing the basic structure of a digital control computing device in which input and output processing steps A and C and control operation processing step B are loaded as programs. 3B is a program execution order control unit that controls the program execution order, 3C is an output processing unit movement request output to the program execution order control unit 3B together with the output processing movement data 3D from the program execution unit 3A, 3
E is a movement command of the output processing step C output to the program execution unit 3A based on the movement request 3C of the output processing step C, the movement data 3D including the rotation angle data and the speed command, and executes the program according to the movement command. Part 3
A outputs a stop command to the actuator. Incidentally, in the program execution order control unit 3B estimation means 3B _1, includes moving means 3B _2.

Next, the operation of one embodiment of the present invention will be described with reference to FIGS. Normally, the output processing step C is executed immediately after the control calculation step B as shown in FIG. 2. However, the control calculation step B indicates that there is an optimum stop command output timing within the next one cycle after the end of the control calculation. Only when it can be determined, the timing of the output processing step C is shifted as shown in FIG.
Then, a stop command is output.

A method of shifting the output execution timing of the control command is as follows. If it is determined in the control calculation step B of FIG. 2 that there is an optimum stop command output timing in the next one cycle, the rotation data of the stepped sleeve 1 calculated in the control calculation step B, that is, the stepped sleeve 1
Based on the distance between the stepped portion 2 of the steel plate 3 and the tip of the steel plate 3 and the speed command of the motor, the control command output processing step C for generating the motor stop command is performed in comparison with the normal case shown in FIG. And how much to shift the movement data Δt
(3D) (FIG. 2 (B) refer) and pass the move request 3 C to the program execution order control unit 3B as shown in FIG.

The program execution order control unit 3B, to which the movement data 3D and the movement request 3C have been passed, becomes the program execution order control unit 3B shown in FIG.
As shown in (B), the execution position of the output processing step C is denoted by Δt.
Just move and shorten from the normal position. As a result, after performing the control calculation, the program execution unit 3A executes the output processing step C whose timing has been shifted.

In the next sampling period, the movement request 3C is sent from the program execution unit 3A to the program execution order control unit 3B.
Are not output, the program execution unit 3A processes the position control program according to the procedure shown in FIG.

In the above embodiment, the case where the specific part of the rotating device is stopped at the fixed position at the tip of the stopped steel plate 3 has been described. However, as shown in FIG. The same effect as in the above embodiment can be obtained even in the case where the output processing for giving a control command to another device M is performed when the tip reaches the specific position.

[0018]

As described above, according to the present invention, the estimating means for estimating at which timing position in the next sampling cycle a control command is to be output, and the output timing position of the control command according to the estimation result. A moving means for moving is provided, the control command output for the control target is estimated at which point in the next sampling cycle should be output, and the control command output timing is moved and executed at the estimated point in time. High-precision control can be performed irrespective of variations in the sampling period.

[Brief description of the drawings]

FIG. 1 is a side view showing a control target according to an embodiment of the present invention.

FIG. 2 is a timing chart showing a processing execution procedure according to an embodiment of the present invention.

FIG. 3 is a functional block diagram showing an embodiment of the present invention.

FIG. 4 is a side view showing another control target according to the embodiment of the present invention.

FIG. 5 is a timing chart showing a processing execution procedure of a conventional digital control computing device.

[Explanation of symbols]

3A program executing section 3B the program execution order control unit 3B ₁ estimator 3B ₂ moving means A input processing unit B control calculation unit C output processing unit

Claims (1)

(57) [Claims] 1. A control command for a control target is generated by performing arithmetic processing on input-processed data, output to the control target, and output processing of the control command depending on an amount of control data taken in by the input process. a program execution unit for executing Thai Mi ring of determining whether delayed until the next sampling period, when the slippage is determined, the one to execute the output processing of the control command at any timing position in the next sampling period Estimating means for estimating from a control amount for a control target, and moving means for outputting a moving command for moving the output processing of the control command to the estimated timing position to the program execution unit, wherein a program is executed in accordance with the moving command. Patent that the execution unit which executes the output processing of the control command by the determined timing position in the next sampling period Digital control computing device.