JP2906773B2 - Industrial robot controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an industrial robot in which a temperature sensor is built in a motor of a manipulator or a rotation detector directly connected to the motor.

[0002]

2. Description of the Related Art Conventionally, when a motor for driving a manipulator is overloaded and the motor temperature rises, a rise in temperature is detected by a temperature sensor built in a motor or a rotation detector directly connected to the motor, When the temperature exceeds the allowable value, an alarm is issued, and further, the power supply for driving the motor driving the manipulator is cut off and the brake is applied. Thereafter, the manipulator could not be driven until the temperature detected by the temperature sensor fell below the allowable value.

[0003]

In the prior art, once the temperature rises and exceeds an allowable value, the power supply for driving the motor is cut off and the operation of the manipulator is prohibited. Such a situation mostly occurs when an industrial robot is actually working on a production line. If the manipulator is prohibited from operating due to a rise in temperature during actual work, and is stopped until the motor temperature falls below the allowable value, the production line becomes inoperable during that time. For example, when carrying a work to convey a work to the driver's seat of a car, the robot stops while the manipulator arm is inserted into the car's driver's seat, and when the operation is prohibited, the transfer conveyor that conveys the car is Operation is prohibited,
There has been a problem that the operation of all the production lines related to the conveyor has been stopped, and the ripples have a great deal of damage. However, when the temperature of the motor rises above the allowable temperature, the manipulator is used under marginal conditions, and it is not so often when the manipulator is manually moved from the danger zone of the production line to a safe zone. Does not load the motor. The present invention has been made in view of such circumstances, the temperature rise exceeds the allowable value and stopped,
It is an object of the present invention to provide an industrial robot apparatus having means for canceling the prohibited state when the operation is prohibited.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and detects a temperature by a motor for driving a manipulator or a temperature sensor built in a rotation detector directly connected to the motor. and means for outputting a signal when the temperature exceeds the upper limit value, means for warning when it detects the signal, and means for interrupting the driving power of the motor at the time of warning, the moving speed when the signal occurs Low
The present invention is characterized in that it is provided with limiting means for turning on the drive power of the motor and enabling operation only in the manual mode limited to the speed, and means for displaying that the limitation is being performed during the limitation.

[0005]

According to this, even when the temperature rise exceeds the allowable value and the operation is stopped and the operation is prohibited, the operator can judge it.
The prohibition state can be released if necessary.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. 1 is an absolute encoder (hereinafter referred to as an encoder), 2 is a temperature sensor, and 3 is a control CPU 3 for controlling the encoder. The encoder 1 also has a function of outputting an absolute position signal and an incremental pulse. The output pulses (A phase, B phase, C phase) of the encoder are
Output via 9 and 10. However, as described later, in the present invention, the signal lines 7, 9, and 10 are used not only as simple output lines but also as two-way signal lines for notifying an abnormal state and confirming it. Reference numeral 4 denotes a temperature sensor attached to the encoder, and reference numeral 2 denotes an A / D converter for converting an analog output of the temperature sensor 4 into a digital value. The control CPU 3 takes in the output of the A / D converter 2 every control cycle and compares it with an allowable value. When the temperature of the motor 5 to which the encoder 1 is attached rises due to overload or the like,
Since the temperature of the absolute encoder also increases, the output value of the temperature sensor also increases. The control CPU 3 has A /
If the read value exceeds the allowable value when reading the output of the D converter, the serial communication CP
U8 is notified that the encoder 1 is in the alarm state, and the pulse output line 10 is switched to the input state.

[0007] When the serial communication CPU 8 knows that the encoder is in the alarm state, it requests the control CPU 3 via the signal line 10 to report the cause of the alarm. The control CPU 3 notifies the serial communication CPU 8 via the signal line 9 that the temperature sensor 4 is overheated. When the serial communication CPU knows that the temperature sensor 4 is overheated, it informs the CPU 11 of the robot controller via the bus 22 that the temperature sensor 4 is overheated.
When the CPU 11 of the robot controller detects the overheating state, the CPU 11 of the robot controller cuts off the driving power supply 23 through the signal line 14 with the driving power supply cutoff device 13 of the motor driving device 6, and supplies the motor driving device 6 with the current to the motor 5 through the signal line 12. To shut off.
Further, the brake is applied to the motor 5 by the brake control device 15 through the signal line 16. Further, the robot control device 1
7, an alarm is displayed on the display device 18 indicating that the encoder is overheated. In this case, since the serial signal is put on the pulse output line, the position of the feedback pulse cannot be managed.
Drop everything. Thereafter, when the system is turned on again, if the temperature sensor 4 is in an overheated state, the control CPU 3 again sets the encoder 1 to an overheated state and enters an alarm state.
U8 is notified that the temperature sensor of the encoder is overheated, and the pulse output line 10 is switched to the input state. The serial communication CPU 8 informs the CPU 11 of the robot controller 17 via the bus 22 that the temperature sensor 4 is overheated.

The CPU 11 of the robot controller 17 requests the control processor 3 through the serial communication CPU 8 to ignore any value of the output of the A / D converter 2. That is, even if the temperature sensor outputs an overheated state, it is ignored. The CPU 11 of the robot control device stores in the memory 21 via the bus 22 that the temperature sensor is currently overheated, and displays on the display device 18 that the encoder is overheated. Further, the CPU 11 of the robot controller permits the manipulator driving operation by the operator only when the robot controller 17 is set to the manual mode. That is, only when the robot controller 17 is designated to the manual mode, the drive power supply 23 is turned on from the drive power supply cutoff device 13 of the motor drive device through the signal line 14 of the motor drive power supply, and The electric current to the motor 5 is supplied to the motor driving device 6. Further, it instructs the brake control device to release the brake of the motor through the signal line 16. In this state, the operator can manually drive the manipulator, and can withdraw the stopped manipulator in the production line to a safe area. After retreating the manipulator to a safe area, turn off all power supplies in the block diagram shown.
After a while, when the power is turned on again and the temperature sensor is not in an overheated state, the control CPU 3 informs the CPU 1 of the robot controller through the serial communication CPU 8 that the temperature is normal.
Inform 1 When the CPU 11 of the robot controller recognizes that it is normal, it allows the operator to energize the motor and release the brake.

Although the case where the temperature sensor is built in the absolute encoder has been described above, the temperature sensor may be built in the motor itself. Further, if the output of the A / D converter is directly monitored by the CPU 11 of the robot controller, it is not necessary to perform serial communication as described above or to temporarily turn off the system. However, in this case, the serial communication CPU 8 and the AD
A signal line connecting the converter 2 is required.

[0010]

As described above, according to the present invention, when the manipulator is operating in the danger zone of the production line, the motor temperature rises due to an overload condition or the like, and the temperature sensor built in the manipulator is overheated. Even if the manipulator is stopped upon detection of a manual operation, a manual operation that can move only at a low speed allows the operator to retreat to a safe area while confirming the danger and quickly restore the production line.

[Brief description of the drawings]

FIG. 1 is a block diagram of a system illustrating the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absolute encoder, 2 A / D conversion device 3 Control CPU 4 Temperature sensor 5 Motor 6 Motor drive device 8 Serial communication CPU 11 Robot control device CPU 13 Motor drive power supply cutoff device 15 Brake device 17 Robot Control device 18 Display device 19 Keyboard 20 Memory 23 Power supply for motor drive

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ identification code FI G05D 3/00 G05D 3/00 X (58) Field surveyed (Int.Cl. ⁶ , DB name) G05B 19/18 G05B 19 / 406 G05B 19/414 B25J 19/06 G05B 9/02 G05B 23/02 302

Claims (2)

(57) [Claims] A means for detecting a temperature by a motor for driving a manipulator or a temperature sensor built in a rotation detector directly connected to the motor, and outputting a signal when the temperature exceeds an upper limit value; Means for giving a warning when detected, means for cutting off the drive power of the motor at the time of the warning, and turning on the drive power of the motor only in a manual mode in which the moving speed is limited to a low speed when the signal is generated. A control device for an industrial robot, comprising: a restricting means operable; and means for displaying that restriction is being performed during the restriction. 2. A temperature sensor incorporated in a rotation detector directly connected to a motor for driving a manipulator detects a temperature, and when the temperature exceeds an upper limit, an original rotation position detection signal output line of the rotation detector. Means for outputting an abnormal signal using the above, and a robot control device that has received the signal,
Using the rotation position detection signal output line to issue a signal for confirming the reason for the abnormality, and displaying a warning if the reason returned via the rotation position detection signal output line is due to exceeding the upper limit temperature, Shut off the drive power of the motor,
An industrial system comprising: a limiting means for turning on the drive power of a motor to operate only in a manual mode in which a moving speed is limited to a low speed; and a means for indicating that the motor is being limited during the limitation. Robot control device.