Robot Gripper Safety Factor Control for Eccentric Object Handling

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Solution Overview

Problem

Conventional handling devices face challenges in stably holding objects of varying sizes and weights due to limitations in grip versatility, particularly with large or eccentrically weighted objects, where friction holding methods may fail to maintain stability during transport.

Innovation Solution

A handling device equipped with two or more supporting parts that calculate a safety factor to determine the optimal grip position and pressure, ensuring stable holding by adjusting the grip based on the object's size, weight, and shape, using sensors and a control system to adjust the grip mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If friction holding is used to hold various objects freely, then the versatility of holding methods is improved, but the stability of holding large or eccentric objects deteriorates

Engineering Contradiction:
Improveholding method versatilityVSAvoidholding stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically changes holding parameters (grip position, grip force, supporting part configuration) based on calculated safety factors that consider object weight, center of gravity position, and shape characteristics. This allows the same friction holding mechanism to adapt to both small objects and large/eccentric objects by adjusting parameters rather than changing the fundamental holding method

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system calculates safety factors based on sensor data about object characteristics and uses this feedback to determine optimal grip positions and forces. The safety factor calculation provides quantitative feedback that guides the control device to adjust holding parameters, ensuring stable holding across different object types while maintaining versatility

Inventive Principle:
Principle #23Feedback

2Ease of operation

If the holding position is set close to the center of gravity for complicated shapes, then the ease of operation is improved, but the reliability of holding large or eccentric objects deteriorates

Engineering Contradiction:
Improveholding position selectionVSAvoidholding stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system automatically adjusts the holding position parameter based on the calculated safety factor, which considers the object's center of gravity position, weight, and shape. For eccentric objects, the system may deliberately select a holding position that optimizes stability rather than simply choosing the center of gravity, thereby maintaining reliability while keeping operation simple through automated parameter optimization

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the hand size is reduced to increase precision, then the manufacturing precision is improved, but the adaptability to hold various sized objects deteriorates

Engineering Contradiction:
Improveholding precisionVSAvoidobject size range
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The holding part features movable supporting parts that can change their relative positions and configurations dynamically. This allows a compact holding structure to adapt its effective size and shape to match various object dimensions, maintaining precision through controlled movement while achieving versatility through reconfigurable geometry

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The holding part is divided into multiple movable supporting parts that can be independently positioned and configured. This segmentation allows the system to maintain a compact overall structure while creating different effective holding configurations for objects of various sizes, thereby preserving precision while increasing adaptability

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 device effectively stabilizes the holding of objects by selecting the best grip method based on calculated safety factors, preventing objects from falling during transport, even when they are large or have an off-center gravity, thereby enhancing handling precision and reliability.

Implementation Method 1

a strain gauge that detects a change in resistance in response to an applied force

Methodology Applied
Scientific EffectStrain gauge resistance change: Piezoresistive Effect

Implementation Method 2

a three-dimensional sensor that detects a shape of the object based on light that is reflected from the object

Methodology Applied
Scientific EffectLight reflection detection: Reflection

Data Source

PatentEP3881979A1Handling device and control device
Publication Date: 2021.09.22 KK TOSHIBA
  • EP3881979A1 patent drawingFigure 1
  • EP3881979A1 patent drawingFigure 2
  • EP3881979A1 patent drawingFigure 3

AI summary

A handling device (10), e.g. a robot comprising a holding part (200) that includes two or more supporting parts (201) , e.g. a gripper holding an object (O), wherein a safety factor is calculated , indicating safety of a state of the holding part (200) holding the object (O), in particular how safe the object (O) is held, e.g. small contact area and/or grip friction, and wherein the object (O) is held and moved according to the calculated safety factor, e.g. in high or low speed motion.