Robot Gripper Slip Detection for Adaptive Clamping Force

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Solution Overview

Problem

Robotic grippers face challenges in adapting clamping forces to prevent slippage without causing damage or excessive energy consumption, especially with multi-finger grippers, and existing methods are complex and costly.

Innovation Solution

A robotic gripper with sensors that detect relative movement and a control system using machine learning to adjust clamping forces based on slip detection scores, iteratively and incrementally, without requiring force or friction measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clamping force is increased to prevent slippage, then the grip stability is improved, but the energy consumption increases and the object may be damaged

Engineering Contradiction:
Improvegrip stabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements a feedback control system that uses sensors to detect slippage and dynamically adjusts the clamping force. The control system receives sensor data indicating relative movement between the gripper and object, processes this information through machine learning algorithms to determine slip detection scores, and adjusts the clamping force accordingly. This feedback mechanism ensures the gripper applies only the necessary force to maintain grip stability, avoiding excessive energy consumption and object damage.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs dynamic adjustment of clamping force based on real-time slip detection. Instead of applying a constant high clamping force, the system dynamically modulates the force level according to detected slippage conditions. The machine learning model iteratively adjusts the clamping force in response to changing grip conditions, allowing the gripper to adapt to varying object properties and external disturbances while minimizing energy consumption.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the clamping force is increased to prevent slippage, then the grip stability is improved, but the object may be damaged by excessive force

Engineering Contradiction:
Improvegrip stabilityVSAvoidobject damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The feedback control system continuously monitors grip conditions through sensors and adjusts clamping force in real-time. By detecting slippage and responding with minimal necessary force increases, the system maintains grip stability while avoiding excessive forces that could damage the object. The machine learning algorithm processes sensor data to determine appropriate force adjustments, ensuring forces remain within safe limits.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the clamping force parameter dynamically based on detected slippage conditions. Rather than using a fixed high force, the system adjusts the force parameter in response to slip detection scores generated by the machine learning model. This parameter modulation ensures sufficient grip stability while keeping forces low enough to prevent object damage.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If traditional force optimization methods are used to determine minimum forces, then the grip stability is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvegrip stabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical force measurement and optimization systems with a sensor-based detection and machine learning approach. Instead of using multiple force sensors and complex GRASP matrix calculations, the system uses simpler sensors to detect relative movement and employs machine learning algorithms to determine appropriate clamping forces. This substitution reduces device complexity and cost while maintaining grip stability.

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

Solution Approach 2:

The patent uses machine learning models trained on simulation data to replicate the functionality of complex force optimization methods. The neural network is trained offline using GRASP matrix calculations and force optimization algorithms, then deployed as a lightweight model that can quickly determine appropriate clamping forces without performing complex real-time calculations. This copying approach transfers the intelligence of complex methods to a simpler implementation.

Inventive Principle:
Principle #26Copying

Data Source

PatentEP4585375A1Robot gripper and control method
Publication Date: 2025.07.16 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4585375A1 patent drawingFigure 1~2
  • EP4585375A1 patent drawingFigure 3
  • EP4585375A1 patent drawingFigure 4~5

AI summary

A robotic gripper comprising: One or more fingers, at least one actuator for acting on the fingers to grip an object, the gripper comprising at least one sensor sensitive to a relative movement between the object manipulated by the gripper and the latter, this sensor delivering an output signal, - a control system configured to execute at least one machine learning algorithm trained to deliver from the output signal(s) from the sensor(s) at least one slip detection score representative of the algorithm's confidence in the presence of slippage, and to transmit control data to the actuators controlling the finger(s), the control data being generated so as to link the intensity of the forces applied by the finger(s) to said score.