JPS63236105A - Position controller - Google Patents

Abstract

PURPOSE:To prevent the movement of a device after a forcible stop state set by a forcible stop switch is released by changing a target value signal into a position detecting signal received from a position detector at the relevant time point via a target changing circuit when the forcible stop switch is turned on. CONSTITUTION:When a forcible stop switch 15 is turned on, a signal s16 is outputted to a position controller 6 and an action similar to that carried out when a target position is secured owing to a fact that the output of the controller 6 is set at zero. Thus, a device 9 is stopped. At the same time, a relay 103 is energized to close an (a) contact 104 and also to switch a changeover switch 105 to an (a) side terminal. Then, a position detecting signal s13 received from a position detector 10 is supplied to an adder 102 together with a target value signal s3b given from a D/A converter 3. The adder 102 obtains a difference of both signals for production of a difference signal s106 and outputs this signal s106 to an adder 101. The signal s106 shows the difference between the actual position and the target one of the device 9.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a position control device that operates equipment to a preset target position, and particularly relates to a forced stop switch that forcibly stops equipment. This relates to something that prevents the device from starting its operation again even if it is canceled.

(Prior Art) In a multi-function device such as a manipulator, each joint is often moved in a point-to-point motion (hereinafter referred to as PTP motion). This is due to the following reasons. In the case of PTP operation, the upper central processing unit (
Contin
When performing a uous pass operation (hereinafter referred to as CP operation), the host CPU constantly monitors the relative position of each axis,
It is necessary to constantly control the speed of each axis and monitor whether each axis reaches its target value. In other words, during PTP operation, each axis reaches the target value at different timings, so there is no problem, but during CP operation, it is necessary for each axis to reach the target value at the same time.

Therefore, when performing the CP operation, a processing speed matching the actual operating speed of the manipulator is required, and control based on the relative position of each axis is also required, so it is necessary to use a large computer as the host CPU.

On the other hand, during PTP operation, the CPU only needs to transmit the target value once and start each controller, and a small computer is required, resulting in low cost. In addition, in a manipulator that is in practical use (Fatory Au'1ation, hereinafter referred to as FA use), there is no problem with FTP operation due to its work content, so PTP operation is the mainstream for current manipulator control.

The operation of the position control device in the PTP operation will be explained below with reference to FIG. Reference numeral 1 in the figure is the CPU;
A target value signal S2 is input from the external memory 2 to this CPLll. The target value signal S2 input to cpui is D
The data is transmitted to the /A converter 3 as a signal s1a, and when this transmission is completed, a reception completion signal s3a is output from the D/A converter 3 to the CPUI. After inputting this reception completion signal s3a, the CPLI 1 sends a start signal Slb to the D/A converter 3.
Output. After inputting this activation signal @S1b, the D/A converter 3 outputs the target value to the adder 5 as a signal S3b. This adder 5 outputs a signal S5 to the position controller 6,
The output of the adder 7 is inputted as a signal S7 to the speed controller 8, and the signal @S8 from the speed controller 8 causes the device 9 to When the device 9 is driven, a position detector 10 detects the position changed by this drive, and a speed detector 11 detects the driving speed of the device 9.

The speed detection signal s12 of the speed detector 11 is input to the adder 7, and the adder 7 calculates the difference between this speed detection signal S12 and the signal (speed command signal) 86 from the position controller 6. The signal S7 is used to increase or decrease the speed command. Further, the actual position detection signal 813 of the position detector 10 is inputted to the adder 5. Adder 5 receives this real position detection signal s13 and D
The target value signal s3b from the /A converter 3 is compared with the target value signal s3b, and the difference is outputted to the position controller 6 as a difference signal S5.

When the device 9 reaches the preset point IIA (il) by performing the above-described control, the actual position detection signal 813 of the position detector 10 and the target value signal s3b match. That is, the output of the adder 5 S5 becomes zero. Therefore, the input to the position controller 6 and the output of the position controller 6 also become zero. Therefore, the difference at the adder 7 becomes negative, and the speed controller 8
The input to becomes negative, and as a result, the device 9 decelerates and stops.

The position controller 6 outputs a target value attainment signal s14 to the CPU 1 when the input becomes zero. By inputting the target value attainment signal s14, the CPU 1 reads the next target value from the external memory 2 and performs the same operation as described above. The above is the operation during normal operation.

Next, a case where the forced stop switch 15 is operated will be explained. Assume now that the device 9 is operating toward a target value under control by the position control device. In other words, the above-mentioned normal operation is performed. At this time, there may be an obstacle in the direction of movement of the device 9, and if the device 9 continues to move forward, interference with the obstacle may be expected.

In such a case, the forced stop switch 15 is operated to stop the operation of the device 9. In other words, forced stop switch 1
5 turns on, a message @516 to that effect is input to the position controller 6. The position controller 6 makes its output zero by receiving this signal s1B. As a result, an operation similar to the operation when the target value is reached is performed, and the device 9 is stopped. however,
In this case, since the device 9 has not yet reached the target value, the position detection signal 513 (
Difference signal S5 between the actual position of the device 9) and the target value signal s3b
(The output of the adder 5) is not zero but always outputs a difference. Therefore, since the input to the position controller 6 is not zero, the target value attainment signal S14 is not output.

Therefore, if the forced stop switch 15 is turned off, the device 9 will operate again toward the target value.

The above configuration has the following problems. That is, in the current control device, there is a problem in that when the forced stop switch 15 is released, the device 9 restarts.

The reason why the operator operates the forced stop switch 15 is assumed to be because the device 9 is about to interfere with some kind of obstacle, as described above, and this is done in order to prevent such interference. Therefore, if the device 9 moves further toward the target value than the stopped position after the forced stop switch 15 is turned off, this means that the device 9 and the obstacle will interfere. To solve this problem, avoid placing obstacles around the FA equipment, or place only temporary items that can be moved immediately to avoid interference between equipment 9 and obstacles. Although interference is prevented, in nuclear power plants and the like where such external environment cannot be guaranteed, the above-mentioned problems still remain and improvements have been required.

The present invention has been made based on the above points, and its purpose is to prevent equipment from restarting after the forced stop switch is turned off, and to prevent malfunctions caused by restarting the equipment, such as problems with the equipment. An object of the present invention is to provide a position control device that can prevent interference with obstacles.

[Structure of the Invention] (Means for Solving the Problems) That is, the position control device according to the first invention is a position control device that operates equipment according to a preset target, and a central processing device that reads a target value from an external memory. a first adder that inputs a target value signal from the central processing unit and a position detection signal from a position detector that detects the position of the device and outputs the difference as a difference signal; A position controller that inputs the difference signal from the adder and outputs a position control signal, and inputs the position control signal from this position controller and the speed detection signal from the speed detector that detects the speed of the above equipment. a second adder that outputs the difference as a difference signal; a speed controller that inputs the difference signal from the second adder and outputs a speed control signal to the device;
a forced stop switch that outputs a forced stop signal to the position controller in order to forcibly stop the equipment; and a target value changing circuit that outputs the position detection signal from the position detector to the first adder as a target value signal when the forced stop switch is turned on. That is.

Further, a position control device according to a second invention is a position control device that operates a device according to a preset target.
A central processing unit that reads a target value from an external memory, and a main unit that inputs a target value signal from this central processing unit and a position detection signal from a position detector that detects the position of the equipment, and outputs the difference as a difference signal. a position controller that inputs the difference signal from the first adder and outputs a position control signal, and a speed detector that detects the position control signal from the position controller and the speed of the device. A second circuit that inputs the speed detection signal from the device and outputs the difference as a difference signal.
a speed controller that inputs the difference signal from the second adder and outputs a speed control signal to the device, and a forced stop signal to the position controller to forcibly stop the device. A forced stop switch is inserted on the output side of the central processing unit, and normally outputs the target value signal from the central processing unit to the first adder, and when the forced stop switch is turned on, the above position is set. a target value changing circuit that outputs the position detection signal from the detector as a target value signal to the first adder; and a target value changing circuit that outputs the position detection signal from the position detector as a target value signal to the first adder; The present invention is characterized by comprising a position detection signal correction circuit that outputs a correction signal obtained by adding a difference from a target value to the first adder.

(Operation) In other words, in the case of the first invention, when the forced stop switch is turned on, the target value signal is changed to the position detection signal from the position detector at that time by the target change circuit, and the forced stop switch is thereby changed. This prevents the equipment from moving after the forced stop state is released.

In the case of the second invention, the target changing circuit changes the position detection signal from the position detector as a target value, and at the same time, the correction circuit corrects the position detection signal from the position detector to the first adder. The target value signal is outputted to the first adder as the same signal as the target value signal, thereby compensating for the time delay caused by only the target changing circuit.

(Example of Eggplant) An example of the second invention will be described below with reference to FIG. It should be noted that the same parts as in the prior art are denoted by the same reference numerals and the explanation thereof will be omitted. Reference numerals 101 and 102 in the figure are adders, respectively, and the adder 102 receives a position detection signal s13 from the position detector 10 and a target value signal s from the D/A converter 3.
3b is input. The adder 102 takes the difference between these two signals and outputs a difference signal 5102 to the adder 101.

The adder 101 receives this difference signal 5101 and the position detector 1.
The position detection signal S13 from 0 is input, and the difference between these two signals is taken and outputted to the adder 5 as a difference signal 5101. Further, reference numeral 103 in the figure is a first relay, and this first
The relay 103 is energized by the ON operation of the forced stop switch 15. The relay 103 is provided with a normally open contact (hereinafter referred to as a contact) 104 and a changeover switch 105, of which the a contact 104 is inserted on the output side of the adder 102, and the changeover switch 105 is connected to the CP
It is inserted on the output side of tJl. Further, reference numeral 106 in the figure is an A/D converter, and the position detection signal s13 from the position detector 10 is input to this A/D converter 106.
This position detection signal S13 is converted by the A/D converter 106 and then output as a signal 5106 to the a side terminal of the changeover switch 105. And the changeover switch 105
is normally closed to the b side terminal, that is, the cpui side, and when the forced stop switch 15 is turned on, the relay 103
When the terminal is excited, it switches to the a side terminal. Furthermore, the reference numeral 107 in the figure is a second relay, and this second relay 107
is energized by the target attainment signal 514 from the position controller 6, and the energization of this second relay 107 opens a normally closed contact (hereinafter referred to as a contact) 108. This b
When the contact 108 is opened, the relay 103 becomes de-energized, and when the a contact 104 is opened, the changeover switch 1
05 is switched to the CPU1 side (b). This restores the original state.

The operation will be explained based on the above configuration. First, CPtJl
A target value signal s2 is inputted from the external memory 2 to. C
The target value input to PLll is sent to the D/A converter 3 as a signal S.
1a, and when this transmission is completed, a reception completion signal s3a is output from the D/A converter 3 to the CPU.

After inputting this reception completion signal s3a, the CPU 1
/A start signal S1b is output to the A converter 3. After inputting this activation signal Slb, the D/A converter 3 inputs the adder (first
The target value is output to the adder) 5 as a signal s3b. This adder 5 outputs a signal S5 to a position controller 6, and the position controller 6 outputs a signal S6 to an adder (second adder) 7. The output of this adder 7 is sent to the speed controller 8 as a signal S7.
The device 9 is driven by the signal S8 from the speed controller 8. When the device 9 is driven, a position detector 10 detects the position changed by this drive, and a speed detector 11 detects the driving speed of the device 9. The speed detection signal 812 of the speed detector 11 is input to the adder 7, and the adder 7 calculates the difference between this speed detection signal S12 and the signal (speed command signal) s6 from the position controller 6 to calculate the difference. Command @S7 and increase/decrease the speed command. Further, the actual position detection signal 813 of the position detector 10 is inputted to the adder 5. The adder 5 receives this real position detection signal s13 and the D/A
It compares the target value signal S3b from the converter 3 and outputs the difference therebetween to the position 11Jtlll unit 6 as a difference signal S5.

When the device 9 reaches a preset target value by performing the above-described control, the actual position detection signal s13 of the position detector 10 and the target value signal s3b match. In other words, the output S5 of the adder 5 becomes zero. Therefore, the input to the position controller 6 and the output of the position controller 6 also become zero. Therefore, the difference at adder 7 becomes negative, the input to speed controller 8 becomes negative, and as a result, equipment 9 decelerates and stops.

The position controller 6 outputs a target value attainment signal S14 to the CPU 1 when the input becomes zero. By inputting the target value attainment signal s14, the CPU 1 reads the next target value from the external memory 2 and performs the same operation as described above. The above is the operation during normal operation, and is similar to the operation described in the description of the conventional example.

Next, a case will be described in which the operation of the device 9 is forcibly stopped by operating the forced switch 15. At this time, the position control device performs the operations described above in order to move the device 9 to a predetermined position. Then, when the forced stop switch 15 is turned on, a signal s1 to that effect is sent.
6 is output to the position controller 6. The position controller 6 makes its output zero in response to this signal 816. Since the output of the position controller 6 becomes zero, the same operation as when the target is reached is performed and the equipment 9 is stopped. At the same time, force stop switch 1
5, the relay 103 is excited. The energization of the relay 103 closes the a contact 104 and switches the changeover switch 105 to the a side terminal. The adder 102 receives a position detection signal 91 from the position detector 10.
3 and the target value signal s3b from the D/A converter 3 are input, and the adder 102 takes the difference between these two signals and generates a difference signal 5.
As 106, it is output to the adder 101 via the a-contact 104. The difference signal 5106 indicates the difference between the actual position of the device 9 and the target value. In the adder 101, this difference signal 6106 and the position detection signal s13 are input and added. Signal 5101 from adder 101 is output to adder 5.

Here, the signal 5101 is the difference signal 51 at the actual position of the device 9.
06 is added, so it is exactly the target value itself. Therefore, the output S5 of the adder 5 becomes zero, and the output S6 of the position controller 6 also becomes zero. As a result, a target attainment state is created in a simulated manner, and the position controller 6 receives a target attainment signal 91.
4 to CPU 1.

On the other hand, the position detection signal 813 is input to the A/D converter 106, and after being A/D converted, it is input as a signal 5106 to the D/A converter 103 via the a side terminal of the changeover switch 105. The signal 5106 is the actual position of the device 9 and means that the target value is changed to the current position of the device 9. At that time, the adder 102 uses the position detection signal 81
3 and target value signal s3b are input, and this target value signal s3
Since b corresponds to the above signal 8106, the signal 5102 becomes zero. Therefore, the output 510 of adder 101
1 is the same as the position detection signal 813, so the adder 5
The output S5 also becomes zero. Therefore, the position controller 6 outputs a target value reception signal (which has the same meaning as a target value attainment signal) S14.

By outputting this target value reception completion signal 814, the relay 10
7 is excited, and the b contact 108 is opened.

When the b contact is opened on the 10th day, the a contact 104 is opened and the selector switch 105 is switched to the b side terminal, returning to the original state. In this restored state, the target value matches the current position of the device 9, and the output S5 of the adder 5
is zero, and the output of the position controller 6 is also zero, so
The device 9 will not be moved again.

According to the ninth embodiment, the following effects can be achieved.

According to this embodiment, even if the forced stop switch 15 is turned from on to off, the device 9 does not move again, so the forced stop switch 15 is operated to prevent the device 9 from interfering with obstacles. In such a case, even if the forced stop switch 15 is turned off, the device 9 will not move, so interference with obstacles is reliably prevented.

(2) At that time, re-movement of the device 9 is regulated by simply changing the target value to the current position of the device 9, but it is expected that the device 9 will move slightly due to problems such as responsiveness. In this regard, in the case of this embodiment, when changing the target value, first the adder 101
Since the output of the adder 7 is set to zero by the action of It has improved significantly.

The above effects will be explained with reference to FIG. 2. In the case of the example shown in FIG. 2, the device 9 is rotated by a drive motor 111, and is at the position indicated by the symbol in the figure before operation. Then, it gradually moves to the target position (indicated by ■ in the figure) under the control of the movement control device (at that time, if it is found that there is an obstacle 112 in the direction of rotation, the forced stop switch 15 is activated. As a result, the above-mentioned operation is performed, and the device 9 is forcibly stopped at the position shown by ■ in the figure.At the same time, the target value changes from the position shown by symbol ■ in the figure to the position shown by symbol ■ in the figure. Therefore, even if the forced stop of the device 9 is canceled, the target value itself has been changed to the current position, so it will not start moving again.

Therefore, interference between the device 9 and the obstacle 112 is reliably avoided.

In the case of the first invention, there is only a target change circuit, so in the worst case, it is expected that the device 9 will move slightly due to a slight time delay, but if the distance to the obstacle is long, Interference will be reliably prevented, and even if interference occurs, major accidents will be prevented.

[Effects of the Invention] As detailed above, according to the position control device according to the present invention, even if the forced stop switch is turned off to avoid the forced stop state, the equipment will not start moving again. Even if there is an obstacle in the moving direction of the device and the device is forcibly stopped, the situation in which the device starts moving again after the forced stop state is released and interferes with the obstacle can be avoided.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are diagrams showing one embodiment of the present invention.
1 is a block diagram of a position control device, FIG. 2 is a diagram for explaining the effect, and FIG. 3 is a block diagram of a conventional position control device. 1...CPtJ, 2...External memory, 3...D/
A converter, 5... Adder, 6... Position controller, 7,
101゜102...Adder, 8...Speed controller, 9
...Equipment, 10...Position detector, 11...Speed detector, 15...Forced stop switch, 103.107.
... Relay, 104... Normally closed contact, 105... Changeover switch, 108... Normally closed contact. Applicant's agent Patent attorney Takehiko Suzue Foil Figure 1■ Figure 2

Claims (2)

[Claims] (1) In a position control device that operates equipment according to a preset target value, there is a central processing unit that reads the target value from an external memory, and a position detector that detects the target value signal from this central processing unit and the position of the equipment. a first adder that inputs a position detection signal from the adder and outputs the difference as a difference signal; a position controller that inputs the difference signal from the first adder and outputs a position control signal; a second adder that inputs the position control signal from the position controller and the speed detection signal from the speed detector that detects the speed of the device and outputs the difference as a difference signal; a speed controller that inputs a difference signal from the device and outputs a speed control signal to the device; a forced stop switch that outputs a forced stop signal to the position controller to forcibly stop the device; and a forced stop switch that outputs a forced stop signal to the position controller to forcefully stop the device; It is inserted on the output side of the processing device, and normally outputs the target value signal from the central processing device to the first adder, and when the forced stop switch is turned on, the position detection signal from the position detector is output as the target value signal. and a target value changing circuit for causing the first adder to output the target value. (2) In a position control device that operates equipment according to preset target values, there is a central processing unit that reads the target value from an external memory, and a position detector that detects the target value signal from this central processing unit and the position of the equipment. a first adder that inputs a position detection signal from the adder and outputs the difference as a difference signal; a position controller that inputs the difference signal from the first adder and outputs a position control signal; a second adder that inputs the position control signal from the position controller and the speed detection signal from the speed detector that detects the speed of the device and outputs the difference as a difference signal; a speed controller that inputs a difference signal from the device and outputs a speed control signal to the device; a forced stop switch that outputs a forced stop signal to the position controller to forcibly stop the device; and a forced stop switch that outputs a forced stop signal to the position controller to forcefully stop the device; It is inserted on the output side of the processing device, and normally outputs the target value signal from the central processing device to the first adder, and when the forced stop switch is turned on, the position detection signal from the position detector is output as the target value signal. a target value changing circuit that outputs a target value change circuit to the first adder, and a correction signal that is obtained by adding the difference between the position detection signal and the target value to the position detection signal from the position detector when the forced stop switch is turned on. A position control device comprising: a position detection signal correction circuit outputting to the first adder.