JPS61139215A - Disconnection detecting circuit for control wire - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a disconnection detection circuit suitable for use in detecting a disconnection in control wiring of a pulse generator for detecting the position of a movable part of an industrial robot, for example.

[Conventional technology]

Industrial robots as shown in FIGS. 4 and 5 have previously been proposed. In FIGS. 4 and 5, +1) is an industrial robot, (2) is a central processing unit (2a), and servo circuits (2b), (2c), and (2R).

(2Z), this industrial robot (1
), (3) is a programming device that programs the operation of this industrial robot (1), and (4) is a teaching device that performs fine adjustment of the program such as the operating position of this industrial robot (1). It is a device.

This industrial robot (1) rotatably supports a first arm (6) at the upper end of a base (5).
), a motor M1 driving this first arm (6);
Drive units such as a tacho generator TG that detects the rotational speed of this motor M1 and a pulse generator PG that detects the rotational phase of this motor M1 are provided. Further, the base of the second arm (7) is fixed to a rotating shaft rotatably provided at the tip of the first arm (6), and the second arm (7) is attached above the base of the first arm (6). A drive unit (8) is provided, including a motor M3 that drives the arm (7), a tacho generator TG that detects the rotational speed of this motor M2, and a pulse generator PG that detects the rotational phase of this motor M2. Further, an operating rod α [on which a chuck (9) is provided is provided at the tip of the second arm (7) so as to be rotatable in the circumferential direction R and movable by a predetermined length in the vertical direction Z.

In this case, a drive unit such as a pulse generator PG, which is composed of a motor MR that drives the rotation of the operating rod α in the circumferential direction R, and a pulse generator that detects the rotational speed and rotational phase, is connected to the base portion (5). ) Connector box (1
1), and a motor Mz for controlling the movement of the operating rod α in the vertical direction Z and a pulse generator PG for detecting the movement speed and the movement position are provided at the lower part of the second arm (7). A drive section (12) is provided. In this case, the control signal from the control device (2) is interrupted via the control line at the connector box (11).
1) Control wiring (13) (13)...
It is supplied to each drive unit of motor Mt+M2, MR and MZ via. This control wiring (13) is connected to motor M1. M
Drive control wiring (13a) that supplies drive signals to z, MR, and Mz, and a servo circuit (2b) that connects output signals from the tacho generator TG or pulse generator PC.
(2e).

(2R), (2Z) Feedback control wiring (
13f') and a wiring (13b) for supplying the output signal from the pulse generator PG to the central processing unit (2a).

In this case, the servo system for motors M1 and Mz is configured as follows. That is, the output voltage corresponding to the rotational speed of the tachogenerator TG of each of the motors M1 and Mz is connected to the feedback control wiring (1
3f) to the servo circuits (2b) and (2C) provided in the control device (2) as comparison signals, and also to the program from the central processing device (2a) and the position signal from the pulse generator PG. The control signals calculated accordingly are supplied to the servo circuits (2b) and (2c), and the output signals of the servo circuits (2b) and (2c) are transmitted through the drive control wiring (13a) and (13a), respectively. It is supplied to motors M1 and Mz as a drive signal.

In addition, the output signals of the pulse generators PG of the motors M1 and Mz are connected to the wiring (13) as rotational phase detection signals.
b) to the central processing unit (2a), and control signals calculated according to the phase detection signals are supplied to the servo circuits (2b) and (2C).

Also, the servo system of motors MR and Mz is
Frequency-voltage conversion circuits (2d) and (2e) generate output voltages according to the frequencies of the output signals of the respective pulse generators PC of Z via feedback control wiring (13f).
) and this pulse generator PG.
The output signals are supplied as position detection signals to the central processing unit (2a) of the control device (2) via the wiring (13b). This pulse generator PC is the motor M1
゜For example, 500 pulses are generated per rotation of Mz, MR, and Mz, and the number of pulses (1
3p).

In this case, the control signal calculated according to the program from the central processing unit (2a) and the position detection signal from this pulse generator PC is transmitted to the servo circuit (2R) and (2).
At the same time, the output voltages of the frequency-voltage conversion circuits (2d) and (2e) are supplied as rotational speed detection signals to the servo circuits (2R) and (2z), respectively. The output signal of (2z) is sent to the motor M via drive control wiring (13a) (13a), respectively.
It is supplied to R and Mz as drive signals, respectively.

This industrial robot (1) has a programming device (
In 3), the operation of this industrial robot (1) is programmed, the program signal from this program device (3) is transmitted to the control device (2) and stored, and this program is executed according to this program signal. The control device (2) generates a control signal, transmits this control signal to the industrial robot (1), and causes the industrial robot (1) to operate according to the program. In this case, if the position of this operation is not accurate, the teaching device (4) supplies a fine adjustment signal for correcting the position to the control device (2), and the control device (2)
Modify the program signal stored in the . In this case, information such as the operation of this industrial robot (1) can be displayed on the monitor (3a) of the programming device (3). Also, when the industrial robot 7) (1) stops working, the program signal stored in the control device (2) must be transferred back to the program device (3), and this program signal must be stored on a floppy disk (3b), etc. control device (2
), and there is no need to back up this storage device.

[Problem that the invention seeks to solve]

In such an industrial robot (1), the second arm (
The drive part (8) of 7) is fixed on the first arm (6), and this drive part (8) moves together with the first arm (6) and also moves in the vertical direction Z of the actuating rod Ql. A drive part (12) for controlling the movement is fixed to the second arm (7), this drive part (12) moves together with the second arm (7), and this drive part (8) and (12) move together with the second arm (7). ) The control wiring (13) from the control box (11) to the control box (11) was constantly bent and stretched, and there was often a risk of disconnection.

In this case, the central processing bag is detected by the pulse generator PC which detects the phase of this motor M2. A pulse (13p) is sent to the central processing unit (2a) from the wiring (13b) that supplies the pulse (13ρ) to (2a) and the pulse generator PC that detects the rotational speed and position of the motor M2.
When the wiring (13b) supplying the servo circuit (
The control signals supplied to 2c) and (2z) are no longer normal, causing this industrial robot to be driven.
) could go out of control, leading to human accidents and mechanical damage.

In view of this point, the present invention provides, for example, an industrial robot (
The purpose is to prevent 1) from going out of control.

[Means for solving problems]

As shown in FIG. 1, the control wiring disconnection detection circuit of the present invention generates a predetermined number of pulses (
13p), a control device (2) that controls the rotation of the rotating bodies M2 and Mz,
The output of this pulse generator PG is
) control wiring (13b).

(13f), this control wiring (13b), (1
3f) to which pulse (13p) peak value, for example 12
A specific voltage supply circuit (14) that applies a specific voltage corresponding to an intermediate level of V, for example, 5V, without disturbing the steady state of this control device (2), and a specific voltage that appears in this control wiring (13b). It consists of a specific voltage detection circuit (15) that detects whether the voltage is high or not.

[Effect]

According to the present invention, the control device (2) is connected to the control wiring (13b).
), a specific voltage corresponding to the intermediate level of the peak value of the pulse (13p) obtained from the pulse generator PC is applied so as not to disturb the steady state of the pulse (13p) obtained from the pulse generator PC. ) is supplied to the specific voltage detection circuit (15), so equivalent detection is not performed, but when this control wiring (13b) is disconnected, this specific voltage, for example 5■, is supplied to the specific voltage detection circuit (15).
), and the disconnection of this control wiring (13b) can be known.

〔Example〕

Hereinafter, one embodiment of the control wiring disconnection detection circuit of the present invention will be described with reference to FIGS. 1, 2, and 3. In FIGS. 1 and 2, parts corresponding to those in FIGS. 4 and 5 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

In this example, in the circuit configuration shown in FIG. 5, the output signals of the pulse generator PC of the motors MZ and M2 are specified in the control device (2) of the wiring (13b) that supplies the central processing unit (2a). A voltage supply circuit (14) and a specific voltage detection circuit (15) are provided. The relationship between the pulse generator PG of the motors Mz and M2, the specific voltage supply circuit (14), and the specific voltage detection circuit (15) will be explained in more detail. ) and the specific voltage detection circuit (15) are representatively shown in FIG.

To explain this FIG. 2, (16a) shows a pulse generating means for generating a number of pulses corresponding to the rotation angle of the motor MZ constituting the pulse generator, for example, a phototransistor when optically generating pulses; The output signal of the generating means (16a) is connected to an npn transistor (
16b) and this transistor (16b
) is grounded, and the collector of this transistor (16b) is connected via a resistor (16c) to a voltage terminal (16d) to which a DC voltage of, for example, 12V is supplied. The pulse (13p) obtained at the collector of this transistor (16b) is supplied to the central processing unit (2a) via the control wiring (13b) as an output signal of the pulse generator PC. In this case, the peak value of the pulse (13p) obtained at the collector of this transistor (16b) is, for example, 12V of the power supply voltage as shown in FIG. 3, and the lowest value is OV when the transistor (16b) is conductive.

(14a) is the peak value of the pulse (13ρ), for example 1
It shows a specific power supply terminal to which a specific voltage corresponding to the intermediate level of 2V, for example, a DC voltage of 5V, is supplied, and this specific power supply terminal (14a) is controlled via a resistor (14b) and a diode (14c) for preventing backflow. It is connected to the wiring (13b) and a specific voltage is supplied to the control wiring (13b). In this case, in the steady state, the transistor (16b)
When is non-conducting, the voltage of this wiring (13b) is pulsed (
13p) is determined by the voltage 12V, and has nothing to do with the specific voltage 5■. Also, when the transistor (16b) is conductive, the voltage of this wiring (16b) is the lowest voltage OV of the pulse (13p), and this It has nothing to do with the specific voltage of 5V.

However, when this wiring (13b) is disconnected, the transistor (18b) is disconnected, so the connection point (13c) between the specific voltage supply circuit (14) and the wiring (13b) is disconnected.
) is this specific voltage, for example 5V.

The input voltage at this connection point (13c) is the first voltage, for example, 8
．． A first voltage detection circuit (15a) whose output signal becomes a high level signal “1” when the voltage is 2V or less, and a second voltage detection circuit whose input voltage is
For example, when the voltage is 1.6 V or more, the output signal becomes a high level signal "1".The output signal becomes a high level signal "1". The output terminals of (15a) and (15b) are pulsed (
13p) at the rise and fall of this specific voltage, for example, 5
In order to prevent the detection of Supplying the output signal of the AND circuit (15e) to the clock terminal of the D-flip-flop circuit (15f),
The output side of this AND circuit (15e) is a high level signal '
1”, this D-flip-flop circuit (15
f) to obtain a control signal at the Q output terminal (15g). In this case, the control signal obtained at the Q output terminal (15g) is used to stop the motor M2, such as turning off the power to the motor MZ.

In this example, the other configurations are the same as those in FIGS. 4 and 5.

Since this example is configured as described above, the wiring (13b
) is not disconnected, the voltage at the connection point (13c) of this wiring (13b) is equal to the pulse (13b) obtained at the collector of the transistor (16b) of the pulse generator PC.
) is determined by the peak value and minimum value of the specific voltage detection circuit (1
5) does not detect an equivalent specific voltage and operates as well as the conventional method.

When this wiring (13b) is disconnected, the connection point (13c)
) and the transistor (16b) of the pulse generator PC
Since it is not connected to the collector of
3c) becomes a specific voltage, for example, 5V, and the output sides of the first and second voltage detection circuits (15a) and (15b) both become a high level signal 61'', which is the time constant circuit (1
5c) and (15d) continues, the output side of the AND circuit (15e) becomes a high level signal ``1'', and a control signal is sent to the Q output terminal (15g) of the D-flip-flop circuit (15f). occurs, which causes motor M
Stop Z and M2.

Therefore, according to this example, when a disconnection occurs in the wiring (13b), this is immediately detected and the motor Mz is disconnected.

Since M2 is stopped, the industrial robot (1) will not run out of control, and since the disconnection can be immediately discovered, repair work can be carried out immediately. Further, by applying this example, it is possible to easily discover errors in wiring work in this part when assembling this industrial robot (1).

Although the above-mentioned embodiment has been described with reference to an example in which the present invention is applied to an industrial robot, it goes without saying that the present invention can also be used in a disconnection detection circuit for control wiring of other devices that control movable parts. Further, the present invention is not limited to the above-described embodiments, and it goes without saying that various other configurations may be adopted without combining the gist of the present invention.

〔Effect of the invention〕

According to the present invention, when the control wiring (13b) is disconnected, it can be immediately detected, and thereby the industrial robot, etc. can be stopped without having to move far, so it is possible to prevent human disasters, It is possible to prevent damage to objects. In addition, the cause of the failure can be clearly known, and repair work can be carried out immediately, which also has the advantage of being useful for future maintenance management.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the control wiring disconnection detection circuit of the present invention, FIG. 2 is a connection diagram showing an example of the main parts of the present invention, and FIG. 3 is a diagram for explaining the present invention. FIG. 4 is a perspective view showing an example of the system configuration of an industrial robot, and FIG. 5 is a system diagram showing an example of the control configuration of FIG. 4. +1) is an industrial robot, (2) is a control device, (2a)
L is the central processing circuit, (2b), (2c),
(2R) and (2Z) are respectively servo circuits, (3)
is the programming device, (4) G is the teaching device, (1
3) is the control wiring, (13b) is the wiring from 4, (14) is the specific voltage supply circuit, (15) is the specific voltage detection circuit, ML,
M2, MR and Mz are motors, respectively, and PC is a pulse generator.

Claims (1)

[Claims] a pulse generator that outputs a predetermined number of pulses according to a rotation angle of a rotating body; a control device that controls rotation of the rotating body; a control wiring that supplies the output of the pulse generator to the control device; A specific voltage supply circuit that applies a specific voltage corresponding to the intermediate level of the peak value of the pulse to the control wiring without disturbing the steady state of the control device, and detects whether or not the specific voltage appears in the control wiring. A control wiring disconnection detection circuit comprising: a specific voltage detection circuit that detects a specific voltage;