Robot Arm Predictive Temporary Stop for Restricted Zone Entry

Solution Overview

Problem

Existing robot systems face inefficiencies due to frequent forced stops when workers enter the robot's operation area, leading to increased downtime and reduced work efficiency, as existing methods require a return operation to resume robot activity after a forced stop.

Innovation Solution

A control method for a robot system that predicts the robot arm's future positions and temporarily stops the robot before entering a restricted area when a potential entry is detected, avoiding the need for a return operation upon resuming, by using a control unit and functional safety unit to manage the robot's operation and safety inputs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the robot arm enters the entry restriction region, then the robot can perform its work, but the worker's safety is compromised and forced stops occur

Engineering Contradiction:

Improvework efficiencyVSAvoidsafety

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The control unit predicts future positions of the robot arm before actual entry into the entry restriction region occurs. By detecting current position and predicting at least one future position, the system takes preliminary action to identify potential safety issues before they materialize, allowing preventive control measures to be implemented.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control unit executes a temporary stop as a preventive measure before the robot arm enters the entry restriction region. This preliminary anti-action counteracts the potential harmful effect of unauthorized entry by stopping the robot arm in advance, avoiding the need for forced stops that would require return operations.

Inventive Principle:

Principle #9Preliminary anti-action

2Reliability

If a forced stop is executed when the robot arm enters the entry restriction region, then safety is ensured, but work efficiency decreases due to required return operations

Engineering Contradiction:

ImprovesafetyVSAvoidwork efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The control unit predicts future positions of the robot arm before actual entry into the entry restriction region occurs. By detecting current position and predicting at least one future position, the system takes preliminary action to identify potential safety issues before they materialize, allowing preventive control measures to be implemented.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control unit executes a temporary stop as a preventive measure before the robot arm enters the entry restriction region. This preliminary anti-action counteracts the potential harmful effect of unauthorized entry by stopping the robot arm in advance, avoiding the need for forced stops that would require return operations.

Inventive Principle:

Principle #9Preliminary anti-action

3Reliability

If the robot arm is temporarily stopped before entering the entry restriction region, then safety is maintained and return operations are avoided, but operation time is increased

Engineering Contradiction:

ImprovesafetyVSAvoidoperation interruption time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The control unit predicts future positions of the robot arm before actual entry into the entry restriction region occurs. By detecting current position and predicting at least one future position, the system takes preliminary action to identify potential safety issues before they materialize, allowing preventive control measures to be implemented.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The control unit dynamically adjusts the robot arm operation by executing a temporary stop only when prediction indicates potential entry into the entry restriction region. This dynamic control approach adapts the stopping behavior to actual operational needs, avoiding unnecessary stops while maintaining safety when required.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP4434689A1Control method, robot system, and non-transitory computer-readable storage medium storing program

Publication Date: 2024.09.25 SEIKO EPSON CORP

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AI summary

In a robot system, when an entry restriction region is enabled and a robot arm enters the entry restriction region, a forced stop of an operation of the robot arm is performed. A control method in which a control unit controls the robot arm includes: detecting a current position of a control point of the robot arm; predicting, using at least position information indicating the current position, at least one position to which the control point of the robot arm moves after a current time point; and performing, when the entry restriction region is enabled and there is a possibility that the robot arm enters the entry restriction region based on the at least one predicted position, control to avoid entry of the robot arm into the entry restriction region, the control including execution of a temporary stop which is a temporary stop of the operation of the robot arm before the robot arm enters the entry restriction region and which does not require a return operation when resuming the operation after the stop.