Robot Arm Speed Zoning With Adaptive Collision Sensitivity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional robot systems require safety fences to separate operators and robots, increasing costs and limiting safety when robots operate in the same workspace as humans, which hampers productivity.

Innovation Solution

A robot system that adjusts collision detection sensitivity between high-speed and low-speed operation regions, allowing higher speeds in high-speed regions while maintaining safety by setting regions closer to operators as low-speed areas with heightened collision detection sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the robot operates at high speed in the same workspace as the operator, then productivity is improved, but safety risk increases

Engineering Contradiction:
Improverobot operation speedVSAvoidsafety risk to operator
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The workspace is divided into high-speed operation regions and low-speed operation regions based on proximity to the operator. The robot operates at high speed in distant regions and automatically reduces speed when entering regions closer to the operator, thereby maintaining productivity while ensuring local safety near the human worker.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The robot's operation speed is made dynamic rather than fixed. The control section automatically adjusts the speed according to the robot's location relative to the operator's workspace, enabling high-speed operation when safe and low-speed operation when near the operator, thus resolving the contradiction between productivity and safety.

Inventive Principle:
Principle #15Dynamics

2Object-affected harmful factors

If safety fence is provided to separate robot and operator workspaces, then operator safety is secured, but introduction cost increases

Engineering Contradiction:
Improveoperator safetyVSAvoidintroduction cost
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical safety fence system with a software-based speed control system. Instead of using physical barriers to ensure safety, the system uses sensors and control algorithms to dynamically adjust robot speed based on proximity to the operator, eliminating the need for expensive safety fences while maintaining safety.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If collision detection sensitivity is increased to detect operator contact, then safety is improved, but false detection rate increases

Engineering Contradiction:
Improvecollision detection accuracyVSAvoidmisdetection rate
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

Different collision detection sensitivities are applied to different regions of the workspace. High sensitivity is used in low-speed regions near the operator where safety is critical, while lower sensitivity is used in high-speed regions where false detections would disrupt productivity. This localized approach balances safety and reliability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The collision detection sensitivity is dynamically adjusted based on the robot's operation speed and location. When operating at high speed, lower sensitivity prevents false detections, while when operating at low speed near the operator, higher sensitivity ensures accurate collision detection, thus resolving the contradiction between safety and reliability.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3238893B1Robot system
Publication Date: 2022.04.13 KAWASAKI JUKOGYO KK
  • EP3238893B1 patent drawingFigure 1
  • EP3238893B1 patent drawingFigure 2
  • EP3238893B1 patent drawingFigure 3

AI summary

A controller (3) is configured to operate a robot arm (10, 12) at a speed that is equal to or lower than a first maximum speed in a high-speed operation region (20H), and operate the robot arm (10, 12) at a speed that is equal to or lower than a second maximum speed lower than the first maximum speed in a low-speed operation region (20L), and change a collision detection sensitivity between the high-speed operation region (20H) and the low-speed operation region (20L) so that the collision detection sensitivity in the high-speed operation region (20H) becomes lower than the collision detection sensitivity in the low-speed operation region (20L).