JPH03142192A - Detecting device for speed abnormality of robot - Google Patents

Abstract

PURPOSE:To increase safety by performing the speed abnormality detection by a hardware circuit even at the approaching work time to a robot during an automatic running mode which is a nonsteady work. CONSTITUTION:In the case of a signal A becoming '1' at automatic operative mode time, an output signal D transmitted from a speed detection circuit inside a servoamplifier becomes null, in the case of the output signal B of a peripheral control system cpu 2 becoming '1'. Namely, at an automatic operative mode time, the signal B is made '1' only at the high speed playback operative time, made '0' during the stoppage or in the low speed playback state by a fencing inside operative mode, etc. and moreover the deburring when a power sensor, etc. is used, and C control time in the case of the low speed of a polishing work time, and the signal D inside the servoamplifier 4 is made effective.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a signal for enabling/disabling a speed abnormality detection function of a hardware circuit of a robot having modes such as teaching and automatic operation.

[Conventional technology]

The conventional device uses the signal of the mode selection switch installed in the operating device, as specified in J15B8433 Industrial Robot Safety General Rules 4.4 Operating Device,
When set to teaching mode, a software speed limit was applied and a hardware speed abnormality detection circuit was enabled.

The speed abnormality detection function described above is a safety function for software abnormalities and abnormal operations that operate at a speed other than the pre-scheduled speed in cases that cannot be detected by software, and double monitoring is performed in the software and hardware circuits. are doing. In the event of an abnormality, an emergency stop process is performed to cut off the power supply to the robot.

In addition, related to this type of function is Japanese Patent Application Laid-Open No. 1-1
38464 etc. are mentioned.

[Problem to be solved by the invention]

The above-mentioned conventional technology does not take into consideration speed abnormality detection during automatic operation mode, and has a problem with the safety function against abnormal operation during stop operation and low-speed cycle operation. That is, there is a large possibility that a person will approach the device during stop operation or low-speed operation, which poses a problem.

The purpose of the present invention is to detect speed abnormalities during automatic driving mode using a hardware circuit, and furthermore, the condition signal for enabling/invalidating the speed abnormality detection function is interlocked with the mode selection signal. Another object of the present invention is to provide a speed abnormality detection device using a hardware circuit that is variable depending on an operating state signal and corresponds to the operating state of a robot in an automatic operation mode.

[Means to solve the problem]

In order to achieve the above purpose, the operating state of the robot is output from a CPU other than the one that monitors the speed abnormality of the robot using software and the contact signal of the mode selection switch installed on the operation panel. Contact signals that open and close depending on the invalid/enable signal for speed abnormality detection, which can be varied, are connected in series, and the contact signal driven by the logical product of these two signals is used as the contact signal of the abnormality detection signal in the hardware speed abnormality detection circuit. A circuit is configured to perform a logical OR operation, and its output is used as an emergency stop request.

[Effect]

The detection presence/absence signal to the speed abnormality detection circuit is passed through the a contact, and the mode selection switch is set to teaching mode! In the case of ・, the output circuit for the above signal is always turned off. That way, no matter what the signal from the software is,
During the teaching mode, speed abnormality detection will be performed. Therefore, the safety function for operation at a safe speed in the teaching mode specified in JIS is comprised only of a hardware circuit.

In addition, the request signal to disable speed abnormality detection, which is output based on the operating conditions of the robot in automatic operation mode, can be generated using a hardware circuit, but even if it is software, the speed Since it is output from a CPU different from the CPU of the servo processing system that monitors the abnormality, it is an independent function and therefore does not malfunction.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 shows a functional block diagram of the robot control device. This control device is used for system management control, robot operation control,
Master CP that controls file management of teaching data, etc.
peripheral control system cpu2.ul and peripheral control system that controls peripheral devices. It consists of a servo processing system CPU 3 that controls the drive motor attached to each axis of the robot based on position data feedback, and data is exchanged between these CPUs by dual port RAM 10a and 10b.
It has a multi-CPU configuration of a distributed processing system in which the PUs can operate independently.

In the case of position level regarding robot movement, mask c
The signal is transmitted to the servo processing system CPU3 via pul. The servo processing system CPU 3 transmits current commands for each axis to the servo amplifier 4 for power control based on the fitback data from the position detection sensor 7a attached to each axis of the robot 7. At that time, the servo processing system CPU 3 converts the position feedback data from the robot 7 not only as position data but also as speed data through differential processing, and based on the deviation from the command value in each of the position system and speed system. Abnormalities in the servo system are constantly detected. In addition, regarding speed abnormality detection, the position feedback data from the robot 7 input to the servo amplifier 4, which is provided separately from the input circuit of the CPUJ section, is converted into the speed of each axis and preset. It is monitored by a speed abnormality detection circuit that outputs an abnormal signal when the speed exceeds the specified speed.

The speed abnormality detection circuit in the servo amplifier is described in detail in Japanese Patent Application Laid-Open No. 1-138464, and its explanation will be omitted.

A request to inhibit speed abnormality detection is issued by the master CPU and transmitted to the ink clock circuit section 5 of the hardware via the peripheral control system CPU2.

The bar I/wear interlock circuit is an emergency stop processing circuit that shuts off the robot's power circuit due to an abnormality in each unit, an emergency stop button, etc., and a servo-on or robot I
- Consists of an interlock circuit that releases the brake. A signal from a mode selection switch installed on the operation panel 6 is also input manually to this interlock circuit, interlocked with the speed abnormality detection prohibition request, and transmitted to the speed abnormality detection circuit of the servo amplifier 4.

FIG. 2 shows a logic circuit of a hardware-based speed abnormality detection function section.

In the teaching mode, the signal A becomes II□I+, and the signal C becomes "0" regardless of the state of the signal output from the peripheral control system CPU2, which is the output from the speed abnormality detection circuit in the servo amplifier. The state of signal 2 becomes the state signal of e. In other words, when it is normal, it is 1'' and when it is abnormal, it is 0''.The signal that is ANDed with the abnormal signal in other servo amplifiers is outputted from the servo amplifier as "1" when it is normal, and "0" when it is abnormal. In the interlock circuit section, the abnormal signal output from the servo processing system CPU 3 is logically ANDed with other abnormal signals that should perform emergency stop processing, and when an abnormality occurs, the signal A instantly becomes +1011. Emergency stop is processed.

Also, if the signal A becomes "1" in the automatic operation mode, the output signal No. 2 from the speed detection circuit in the servo amplifier will be the output signal port (speed abnormality prohibition request) of the peripheral control system CPU2.
If it becomes 1″, it becomes invalid.

In the automatic operation mode, the above signal port is set to "1" only during high-speed playback operation, and it can be used for deburring and polishing when stopped or in low-speed playback state due to fenced operation mode, etc., and when using a force sensor, etc. For low-speed work, etc., the signal is set to "0" during control, etc., and the second signal in the servo amplifier 4 is enabled.

According to this embodiment, double speed abnormality monitoring is performed by Hatoware during the automatic driving mode, so there is an effect of improving safety.

In addition, in this embodiment, speed abnormality detection during high-speed playback may be limited by a current limiter, etc., but if necessary, this function will be added so that it is always activated and an emergency stop is performed in the event of an abnormality. All you have to do is allow the processing to take place.

〔Effect of the invention〕

According to the present invention, speed abnormality can be detected by a hardware circuit even when approaching a robot in an automatic operation mode, which is an unsteady work, thereby improving safety.

Also, if feedback control is performed using force sensors, etc., the robot may malfunction due to abnormalities such as sensors, etc.
Although there is a possibility of damaging the workpiece or tool, this function also has the effect of improving reliability because it can also detect the above-mentioned abnormal operation.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of the robot control device. FIG. 2 is a logic circuit diagram of a hardware-based speed abnormality detection function according to an embodiment of the present invention. 1... Master CPU, 2... Peripheral device control system Cl)
11.3...Servo processing system CPU, 4...Servo amplifier (power control), 5...Hardware ink interlock circuit section, 6...Operation panel, 7...Robot.

Claims (1)

[Claims] 1. In a robot controlled by a computer,
A function to monitor the operating speed of the robot by a hardware circuit, and enable the said function by a signal indicating the operating state of the robot interlocked with a mode selection signal.
A speed abnormality detection device for a robot, characterized in that a means for disabling it is provided. 2. A speed abnormality detection device for a robot according to claim 1, characterized in that a signal that is enabled except during startup in an automatic operation mode is interlocked with a mode (teach/automatic operation) signal. 3. The speed of the robot according to claim 1, characterized in that in the automatic operation mode, a signal indicating a state in which a human can enter the robot's fence is interlocked with a mode (teaching/automatic operation) signal. Anomaly detection device. 4. In claim 1, in automatic operation where low-speed operating conditions are given in advance, the condition signal is set to mode (
A robot speed abnormality detection device that is characterized by interlocking with a teaching/autonomous driving signal.