Two-Stage Robotic Arm Stops for Collision Force Absorption

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing robotic systems lack effective mechanisms to safely limit and stop the rotational motion of robotic arms, which can lead to damage or injury in case of failure.

Innovation Solution

The development of multi-stage stop devices that utilize a compressible member to absorb and dissipate collision forces in the first stage, followed by a hard stop in the second stage to prevent further rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hard stop device is used to limit rotational motion of robotic arms, then damage prevention is improved, but collision forces are not effectively absorbed leading to potential injury or damage

Engineering Contradiction:
Improvedamage preventionVSAvoidcollision force impact
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies beforehand cushioning by incorporating a compressible member (such as a spring or elastomeric element) between the robotic arm and the hard stop. This compressible member is pre-positioned to absorb collision forces before they reach the hard stop, thereby cushioning the impact in advance and preventing direct transmission of harmful forces to the robotic arm or surrounding components.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If a single-stage hard stop is used, then rotational motion is stopped effectively, but the stopping process generates high impact forces that can cause damage or injury

Engineering Contradiction:
Improverotational motion controlVSAvoidimpact force during stopping
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The patent applies segmentation by dividing the stopping function into two distinct stages: a first stage where a compressible member absorbs collision forces through compression, and a second stage where a hard stop prevents further rotation. This segmentation of the stopping process allows the system to handle impact forces gradually rather than through a single abrupt stop, thereby reducing peak impact forces while maintaining effective rotational motion control.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The multi-stage stop devices effectively absorb and dissipate collision forces, reducing the risk of damage or injury, while providing a reliable hard stop to prevent further rotation, thus enhancing the safety and reliability of robotic systems.

Implementation Method 1

the rotational motion compresses a compressible member to absorb and dissipate at least some of the force generated by the collision

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3938150B1Multi-stage stop devices for robotic arms
Publication Date: 2025.04.16 OMRON CORP
  • EP3938150B1 patent drawingFigure 1
  • EP3938150B1 patent drawingFigure 2A~2B
  • EP3938150B1 patent drawingFigure 2C

AI summary

This application describes multi-stage stop devices for robotic arms. During a first stage, rotational motion of a link of a robotic arm compresses a compressible member of the multi-stage stop device to absorb and dissipate at least some of the force generated by the collision. A second stage provides a hard stop the stops any further rotation. The multi-stage stop devices described herein can include a collapsing pin configured to compress a compressible member during the first stage. After the pin has collapsed a rigid sidewall provides a hard stop preventing further rotation during the second stage.