JPS6122806B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a position control device for a device (hereinafter referred to as a side guide) for correctly setting the position of a slab or the like in a rolling line of a steel manufacturing plant, for example.

A conventional device of this type is shown in FIG.

In the figure, 1 is a side guide, 2 and 3 are gears G for transmitting power to the side guide 1, 4 is a mechanical tie position that synchronizes the left and right side guides 1, and 5 is a motor that generates torque according to the voltage. M, 6 is a position detector PLG based on the rotation angle of the motor 5, 7 is a position control device, 8 is a speed control circuit,
Reference numeral 9 denotes an amplifier for the speed reference output of the speed control circuit 8.

Here, details of the position control device 7 will be explained with reference to FIG. 2. The position control device 7 outputs a position control signal according to the speed of the side guide 1 from the maximum speed to the stop, and the position control signal is obtained from the position detector 6 from the position reference value P of the target position at which the side guide 1 should be stopped. Based on the deviation obtained by subtracting the current position value, a corresponding position control signal is output in accordance with the deceleration curve C shown in FIG. In addition,
When the deviation is positive, it corresponds to the speed value in the direction in which the side guide 1 spreads according to the position control signal value, and when the deviation is negative, it is the opposite of what was described above, and the deceleration curve C moves the position reference point P to the origin O It is symmetrical as .

Next, the operation will be explained. The position control device 7 uses a position reference value given from the outside and a position detector 6.
A comparison calculation is made with the current position of the side guide obtained by , and based on the obtained deviation, a position control signal value is outputted to the speed control circuit 8 according to the deceleration curve C shown in FIG. The speed control circuit 8 converts it into a predetermined speed reference current or voltage and outputs it to the amplifier 9. Amplifier 9 outputs driving power for motor 5 according to the speed reference value. The power of the motor 5 operates the side guide 1 via the tie device 4 and the gear 2 or 3. At the same time, the motor 5 rotates the position detector 6, and the position control device 7 reads the change and repeats the above control until the target position is reached.

Since the conventional position control device is configured as described above, if the frictional force generated between the side guide 1 and the gear 2 or 3 and other frictional forces vary depending on the position of the side guide 1, The amount of work required to move varies depending on the target position, and since the deceleration curve is fixed, there is a drawback that stopping accuracy is poor, such as stopping early or overshooting the target position.

The present invention has been made in order to eliminate these drawbacks, and provides a position control device with high stopping accuracy regardless of the target position of the moving body.

An embodiment of the present invention will be described below with reference to FIG. In FIG. 3, the same reference numerals as in FIG. 1 indicate the same or corresponding parts. Reference numeral 10 denotes a motor current detector PG that detects the current of the motor 5. If there is a frictional force, etc. in the drive system of the motor 5, which generates a predetermined torque with a predetermined voltage, the current changes in accordance with the frictional force, etc. You will get it. Reference numeral 11 denotes a frictional force memory device which obtains the frictional force associated with the position of the entire operating range of the side guide 1 from the output of the motor current detector PG when the side guide 1 is actually moved. The frictional force memory device has a current value pulse input function (not shown) and a correction value calculation function (not shown) at a fixed time period, and also has a table (not shown) for storing signals from these functions. There is. Reference numeral 12 denotes a deceleration curve correction device which receives control signals corresponding to the current position input from the position control device 7 and the deceleration curve C shown in FIG. A corrected position control signal is output depending on the value.

Next, the operation of the embodiment of this invention will be explained. First of all, prior to actual operation, the motor 5
is driven to move the side guide 1 over the entire movement range, and at the end of the movement of the side guide 1 over the entire movement range, the above-mentioned periodic processing function calculates a correction value based on the recorded data, Correction values corresponding to the position data of the side guide 1 are stored in the table described above. Here, motor current detector 10
The current value represents the frictional force of the entire drive system to be controlled. As a result, the frictional force corresponding to the position of the side guide 1 is stored in the frictional force storage device 11.
and complete the preliminary operation. Next, the actual operation will be explained. When the position reference value P is given to the position control device 7 from the outside as in the conventional example, the position control device 7 calculates the position reference value P and the current position according to the current position of the side guide 1 obtained from the position detector 6. A position control signal based on the deceleration curve C in FIG. 4 is output to the deceleration curve correction device 12 along with the current position according to the obtained deviation. The deceleration curve correction device 12, which has received the position control signal and the current position, retrieves the friction force value corresponding to the current position from the friction force storage device 11 as a correction value from the above-mentioned table, and adds this correction value to the above-mentioned position control signal. By adding , a modified position control signal according to the modified deceleration curve D shown in FIG. 4 is output to the speed control circuit 8. Note that the above-mentioned position control signal is a speed reference signal given to the speed control circuit 8. The speed control circuit 8 receives the corrected position control signal, converts it into a predetermined speed reference current or voltage, and outputs it to the amplifier 9. The amplifier 9 outputs driving power for the motor 5 according to the speed reference value,
The power of the motor 5 is powered by the tie device 4 and the gear 2 or 3.
Activate side guide 1 via. At the same time, the motor 5 rotates the position detector 6, and the position control device 7 reads the change and repeats the above control until the target position is reached.

Because it acts like this, the effect is,
In the entire operating range by controlling the position of side guide 1,
A correct stopping position can be obtained with respect to the target position regardless of the frictional force related to the side guide 1.

Although the case of the side guide in a steel blunt has been described above, the present invention is not limited to this, and can be applied to a heating furnace bushier, an extractor,
It may also be used to control the position of all other devices, such as various mill screw reduction devices, in which the frictional force varies depending on the position within the entire operating range. Further, although a motor current detector has been described as a means for detecting frictional force, the present invention is not limited to this embodiment.

As described above, the present invention has the advantage that a correct stopping position can be obtained with respect to the target position when position control is performed, regardless of variations in the frictional force over the entire motion range of the moving body. be.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a conventional position control device, Fig. 2 is a graph showing a deceleration curve C, Fig. 3 is a block diagram of an embodiment of the inventive device, and Fig. 4 is shown in Fig. 3. It is a diagram for explaining things. In the figure, 1 is a slab side guide, 2 and 3 are gears for transmitting power to the side guide 1, 4 is a mechanical tie device that synchronizes the left and right side guides 1, 5 is a motor, and 6 is the rotation angle of the motor 5. 7 is a position control device, 8 is a speed control circuit, 9 is an amplifier for the speed reference output of the speed control circuit 8, 10 is a motor current detector, 11 is a friction force storage device, 12 is a deceleration curve correction device It is. In the drawings, the same or corresponding parts are designated by the same reference numerals.

Claims (1)

[Claims] 1. A pair of side guides movable in the left-right direction, a motor for driving the side guides, a position detector for detecting the rotational position of the motor, and a side guide connected to the position detector. a position control device, a motor current detector for detecting the drive current of the motor, a friction force storage device connected to the motor current detector, a speed control circuit connected to the motor, and the position control device. a deceleration curve correction device connected to the frictional force storage device and the speed control circuit, the device comprises a deceleration curve correction device connected to the frictional force storage device and the speed control circuit, the device is configured to apply a frictional force corresponding to a position of the entire operating range of the side guide to the side guide. A position characterized in that the rotation of the motor is controlled via the deceleration curve correction device after storing it in the friction force storage device as a current change of the motor current detector when the motor is actually moved. Control device.