Robot Control Device Emergency Stop Verification

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Solution Overview

Problem

Existing robot control devices rely on manual checks of the emergency stop circuit, which can be forgotten or omitted, potentially compromising operator safety as the functionality is not automatically verified before starting teaching jobs.

Innovation Solution

A robot control device with an emergency stop control unit that automatically confirms the disconnection of the power supply line when switching between operation modes, using a connection/disconnection means and an auxiliary monitor contact to ensure the emergency stop function is operational, and issues an alarm if the disconnection fails, preventing reactivation if the emergency stop circuit is faulty.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual checking of the emergency stop circuit is required before teaching jobs, then operator safety can be confirmed, but the check may be forgotten or omitted reducing reliability

Engineering Contradiction:
Improveemergency stop function reliabilityVSAvoidoperation complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The robot control device automatically performs the emergency stop circuit check itself without requiring manual intervention. The control unit automatically disconnects and monitors the power supply line to the drive motor, verifying the emergency stop function is operational before allowing teaching jobs to proceed, thereby eliminating human error in safety checks

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The emergency stop circuit check is performed automatically in advance before the teaching job begins. The control unit verifies the emergency stop function is working properly prior to allowing the operator to enter the teaching mode, ensuring safety is confirmed before the potentially dangerous operation starts

Inventive Principle:
Principle #10Preliminary action

2Reliability

If automatic emergency stop circuit verification is implemented, then safety is consistently ensured, but device complexity increases

Engineering Contradiction:
Improvesafety verification consistencyVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The existing control unit of the robot control device is enhanced to perform multiple functions: it controls the operation modes (automatic/teaching), manages the power supply to the drive motor, and automatically verifies the emergency stop circuit functionality. By making the control unit multi-functional, the patent avoids adding separate dedicated hardware for safety verification, thus limiting the increase in device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP1785237B1Robot control device
Publication Date: 2011.06.08 FANUC LTD
  • EP1785237B1 patent drawingFigure 1
  • EP1785237B1 patent drawingFigure 2
  • EP1785237B1 patent drawingFigure 3

AI summary

A robot control device includes an operation mode change-over switch for switching between a first operation mode for prohibiting an operator from approaching a predetermined area around a robot when power is supplied to a drive motor for driving the robot and a second operation mode for allowing the operator to approach the predetermined area around the robot even when power is supplied to the drive motor, and an electromagnetic contactor for switching the connection and disconnection of the power supply line to the drive motor. The robot can be stopped in case of emergency by using the electromagnetic contactor to disconnect the power supply line. The apparatus further includes an emergency stop control unit. The emergency stop control unit issues a disconnection command to the electromagnetic contactor, when the switching between the first and second operation modes is sensed, and automatically confirms whether or not the power supply line is disconnected.