JPS5947613B2 - position control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a position control device, and in particular, the present invention compares a feedback signal obtained by detecting the actual movement position of a controlled moving object with a command signal from a position command circuit. This relates to a position control device that automatically stops a moving object when the
For example, it can be used as a position control device for a rolled material in automatic operation of a rolling mill.

Taking a rolling mill as an example, a large number of position control devices are used for automatic operation of a rolling mill, and preset control, automatic centering control, etc. are performed.

FIG. 1 is a block diagram showing an example of a conventional position control device. In FIG. 1, 1 is a drive device that drives a controlled moving body, 2 is a movement position detector that detects the moving position of the moving body and outputs a feedback signal B, and 3 is a command signal A from a position command circuit 4. and the feedback signal B from the moving position detector 2 as input, and compare the two, and depending on the comparison result, the drive device 1
5 is a setting device for setting the command signal A. In such a configuration, control is performed such that when the command signal A matches the feedback signal B based on the comparison result in the discrimination circuit 3, a stop signal is issued to stop the drive device 1. The conventional method for checking the quality of the control system of such a position control device is to have the operator measure the actual moving position using a scale and check whether it matches the command value. However, the current situation is that position control devices and devices are used without periodic checks being carried out, as they cannot be checked unless they are off-line.

Therefore, defects in the control system of the position control device cannot be discovered until after an accident has occurred, and the position control that could lead to a serious accident cannot be automated and is currently operated manually. An object of the present invention is to solve the above-mentioned problems in the prior art, to enable checking online and each time immediately before starting automatic operation, and to stop automatic operation when it is determined that there is a defect in the control system. An object of the present invention is to provide a position control device that can prevent a serious accident from occurring.

A feature of the present invention is that, in order to achieve the above object, the tip of the controlled moving body that starts moving in response to an automatic operation start command has two parts.
Count the number of pulse waves from the pulse generator when moving between the two fixed position detectors, and calculate the measured pulse number and the pulse number corresponding to the true distance between the two fixed position detectors. When the deviation between the two is smaller than the set level, it is determined that there is no abnormality in the control system and automatic operation continues, and when the deviation is greater than the set level, it is determined that there is an abnormality in the control system and a failure is displayed. , the configuration includes a check circuit for stopping automatic operation.

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

FIG. 2 is a block diagram of the present invention, in which a fixed position detector 6, a failure display circuit 7, and a fixed movement amount setter 8 are added to the conventional structure shown in FIG.

Two fixed position detectors 6 are installed so as to detect passage of the tip of the controlled moving body at two fixed positions at the start of automatic operation. The true distance between the two fixed position detectors is known in advance, and an amount equivalent to that distance is stored in the fixed movement amount setter 8.

First, when an automatic operation start command is received, the drive device 1 is activated and the moving object starts moving, and the passage of the tip of the moving object is detected by the two fixed position detectors 6, and the distance equivalent C is detected. is output as

This actually measured distance equivalent amount C and a set amount D corresponding to the true distance stored in the fixed travel amount setter 8 are compared in the discrimination circuit 3, and the deviation between the two is determined by the preset setting. If it is below the level, it is determined that there is no abnormality in the control system, and the command signal given from the position command circuit 4 to the discrimination circuit 3 is, for example, in the case of position control in a rolling mill, the position command value determined by the rolling schedule. At the same time as switching to E, automatic operation continues using the position control device. When the deviation is larger than the set level, it is determined that there is an abnormality in the control system, and the failure is notified to the operator via the failure display circuit 7, at the same time automatic operation is stopped and operation is switched to manual operation. FIG. 3 shows a circuit diagram of an embodiment for realizing the control operation of the configuration shown in FIG. 2 as described above.

This is the case with a position control device for a coal lipter after winding a steel coil in a rolling mill. In FIG. 3, 11 is the coil at the start of winding, 12 is the coil at the end of winding,
13 indicates a call repter. In the conventional control method, after the coil winding is completed, the Colelipter 13 is raised to bring the Coallipter 13 into contact with the coil 12. In this case, the amount of movement of the call repter 13 differs depending on the size of the coil diameter. If the diameter of the coil is small, it takes time to raise the Coal Lipter 13 until it comes into contact with the coil. Therefore, by raising the coil lipor 13 in advance to a position corresponding to the diameter of the coil after winding, production efficiency can be improved. However, if the amount of movement of the call repter 13 is incorrect, not only will the coil be damaged, but in the worst case, the reel drum will also be damaged, leading to a major accident. Therefore, conventionally, automatic printer standby control has not been performed.
In contrast, the present invention aims to make it possible to check in advance whether there is any abnormality in the control system. In FIG. 3, 14 is a position oscillator fixedly attached to the tip of the call repter 13, 15 and 16 are fixed position detectors provided at two fixed positions on the device side, 17 is a pulse transmitter, and 18 is a cylinder, 19 is a solenoid valve, 20 is a power relay, 21 is a control circuit, 22 is a fault indicator, 23
is a counter, 24 is a comparator, 25 is a register, and 26 is a calculator. When the automatic operation start signal is output from the computer 26 to the control circuit 21, the power relay 20, the solenoid valve 19,
The cylinder 18 is driven and the Colelipta 13 starts to rise. When the position oscillator 14 attached to the tip of the call repter 13 passes the position of the fixed position detector 15, the counter 23 is reset and starts counting the number of pulse waves from the pulse oscillator 17 again. When the position oscillator 14 passes the position of the fixed position detector 16, the call repter 13 temporarily stops, and the counter 23 sends the number of pulse waves counted so far to the comparator 24. On the other hand, at the same time as the automatic operation start signal is output, the computer 26 outputs the two fixed position detectors 15 and 16 stored in advance.
The pulse wave number corresponding to the true distance between the two is set and stored in the register 25. The pulse wave number stored in this register 25 is read out by the comparator 24 and compared with the pulse wave number of the count result from the counter 23, and when the deviation between the two is below a preset level, It is determined that there is no abnormality in the control system, and the comparator 24
A signal indicating that automatic operation is possible is sent to the computer 26 from the computer 26. When the computer 26 receives a signal indicating that automatic operation is possible from the comparator 24, it sends a signal to the control circuit 21 to start driving again, and at the same time sets the number of pulses corresponding to the Ripter standby position in the register 25, and raises the Ripter 13 again. let Further, when the above-mentioned deviation that causes the comparator 24 to fail is larger than the above-mentioned set level, the comparator 24 determines that there is an abnormality in the control system, displays the fault on the fault indicator 22, and stops the automatic operation. The signal is sent to the computer 26. As described above, according to the present invention, an automatic driving control device having a position control system
With this system, it is possible to check online for abnormalities in the position control system immediately before setting the actual movement position at the start of automatic operation, improving work efficiency and control system reliability, and preventing serious accidents from occurring. can be prevented.

[Brief explanation of drawings]

Fig. 1 is a block configuration diagram of a conventional device, Fig. 2 is a block configuration diagram of an embodiment of the present invention, and Fig. 3 is a circuit diagram of an embodiment of the present invention. 2...Movement position detector, 3...Position discrimination circuit, 4...
...Position command circuit, 5...Position command setting device, 6
...Fixed position detector, 7...Failure display circuit, 8...Fixed travel amount setting device, 13...
・・・Calllipta, 14・・・Position oscillator, 15
, 16...Fixed position detector, 17...
Pulse oscillator, 18...Cylinder, 20...
...Power relay 21...Control circuit, 22.
...Fault indicator, 23...Counter, 2
4...Comparator, 25...Register, 2
6...Calculator.

Claims (1)

[Claims] 1 In a position control device that compares a feedback signal obtained by detecting the actual movement displacement of a controlled moving object with a command signal from a position command circuit, and automatically stops the moving object when the two match, A fixed travel amount setting device that can set and output a signal corresponding to the distance between two fixed position detections prior to operation, and a fixed movement amount setting device that can set and output a signal corresponding to the distance between two fixed position detections, and an actual a determination means for comparing a feedback signal obtained by detecting the movement position of the signal and determining whether or not a deviation between the two signals is less than or equal to a predetermined value; 1. A position control device comprising: position command means for switching a command signal to the position command circuit from a signal from the fixed movement amount setter to a position command signal for automatic operation when the value is smaller than .