Robotic Arm Joint Accelerometers for Precise Collision Safety Control

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Solution Overview

Problem

Existing collision detection methods in collaborative robots are plagued by low accuracy, low sensitivity, and high costs, posing a risk to human safety due to the proximity of human operators and robotic arms during high-speed movements.

Innovation Solution

A robotic arm equipped with multiple acceleration sensors on its joints, which collect motion information to determine collision position and force, enabling a safety control strategy to be executed, thereby achieving high accuracy and sensitivity collision detection at a lower cost through a control circuit that processes this data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional collision detection methods are used, then the system can detect collisions, but the detection accuracy and sensitivity are low

Engineering Contradiction:
Improvecollision detection accuracyVSAvoidcollision detection sensitivity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The robotic arm is divided into multiple segments (joints), with acceleration sensors installed on each joint. This segmentation allows independent monitoring of each joint's motion state, enabling precise localization of collision events and accurate measurement of collision forces at specific joints, thereby improving both detection accuracy and sensitivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces traditional mechanical collision detection methods with acceleration sensor-based detection. The acceleration sensors convert mechanical collision forces into electrical signals for processing, enabling more accurate and sensitive detection while reducing mechanical complexity and improving response speed.

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

2Reliability

If high-accuracy collision detection is implemented, then safety is improved, but the system cost increases

Engineering Contradiction:
Improvesafety functionVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses acceleration sensors, which are relatively low-cost components compared to other high-precision detection devices. These sensors can be mass-produced and integrated into each joint at minimal cost, enabling high-accuracy collision detection across multiple joints without significantly increasing the overall system cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The acceleration sensors serve multiple functions: detecting collision forces, localizing collision positions, and monitoring joint motion states. This multi-functionality reduces the need for additional specialized sensors, thereby lowering the overall system cost while maintaining high safety standards.

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

3Measurement precision

If multiple acceleration sensors are installed on different joints, then collision detection accuracy is improved, but the device complexity increases

Engineering Contradiction:
Improvecollision position accuracyVSAvoidsensor arrangement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The robotic arm is divided into multiple segments (joints), with acceleration sensors installed on each joint. This segmentation allows independent monitoring of each joint's motion state, enabling precise localization of collision events and accurate measurement of collision forces at specific joints, thereby improving both detection accuracy and sensitivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control circuit receives acceleration data from multiple sensors and processes this feedback information to determine collision events, their positions, and force magnitudes. This feedback mechanism enables the system to automatically adjust its response based on the detected collision characteristics, improving detection accuracy without requiring complex manual intervention.

Inventive Principle:
Principle #23Feedback

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 solution enables real-time, accurate, and sensitive collision detection, ensuring the robotic arm can react appropriately to prevent injuries, meeting industrial safety standards like ISO 10218 and ISO 13849-1, while reducing production costs.

Implementation Method 1

determining that a collision occurs in the robotic arm, and obtaining a first motion information of each joint through a corresponding acceleration sensor

Methodology Applied
Scientific EffectAcceleration sensing: Accelerometer

Data Source

PatentEP4454828A1Robotic arm and safety control method thereof
Publication Date: 2024.10.30 KUKA ROBOTICS GUANGDONG CO LTD
  • EP4454828A1 patent drawingFigure 1
  • EP4454828A1 patent drawingFigure 2~3
  • EP4454828A1 patent drawingFigure 4~5

AI summary

The present disclosure provides a robotic arm and a safety control method thereof. The robotic arm includes a plurality of joints and a plurality of acceleration sensors, and different the plurality of acceleration sensors are arranged on different the plurality of joints. The method includes: determining that a collision occurs in the robotic arm, and obtaining a first motion information of each joint through a corresponding acceleration sensor; determining a position information and a collision force information of the collision occurring based on the first motion information; and obtaining a safety control strategy based on the position information and the collision force information, and controlling the robotic arm to execute the safety control strategy. The present disclosure obtains the first motion information of the joint or joints in the region by means of the acceleration sensor(s) arranged on the joint(s), for determining the position information and collision force information of a collision occurring based on the first motion information, obtains a corresponding safety control strategy based on the position information and the collision force information, and controls the robotic arm to execute the safety control strategy, which is capable of realizing the collision detection of the robotic arm with a high degree of accuracy and a high degree of sensitivity.