3D Force Application Robotic Apparatus with Decoupled Gantry

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Solution Overview

Problem

Existing robotic systems for locomotor rehabilitation, such as those used for spinal cord injury patients, face challenges with high inertia and the need for multiple strong actuators due to non-decoupled degrees of freedom, limiting precise force application in three-dimensional spaces.

Innovation Solution

A robotic apparatus combining passive and active elements to minimize actuation requirements, decouple degrees of freedom, and use differently sized actuators for various load and speed targets, allowing precise force application with lower inertia.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a moving gantry structure is used to allow three-dimensional application of forces, then the workspace and force application capability are improved, but the inertia and device complexity increase significantly

Engineering Contradiction:
Improvethree-dimensional force application capabilityVSAvoidinertia of moving gantry
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The system segments the force application task across multiple fixed gantries, each equipped with independent actuators. Instead of one large moving gantry, multiple smaller fixed structures work cooperatively to provide three-dimensional force application, reducing individual inertia while maintaining overall capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from a single moving gantry in three-dimensional space to multiple fixed gantries arranged in space, where the dimensional capability is achieved through spatial distribution rather than mechanical movement of a single large structure.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If a parallel mechanism with multiple actuators is used to provide three-dimensional support, then the force application range is improved, but the actuator coupling increases system complexity and reduces control precision

Engineering Contradiction:
Improveforce application rangeVSAvoidactuator coupling
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system segments the control architecture so that each actuator controls its own degree of freedom independently. This decoupling allows each actuator to be controlled separately, simplifying the control system while maintaining the ability to apply forces in three-dimensional space through coordinated action of multiple actuators.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using a traditional parallel mechanism where multiple actuators are coupled through a common moving platform, the system inverts the approach by using multiple independent actuators on fixed structures that cooperate to achieve the same goal, eliminating the coupling problem.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If all actuators are dimensioned for the fastest velocity and highest force requirements, then the system can handle extreme conditions, but the cost and device complexity increase

Engineering Contradiction:
Improvesystem performance under extreme conditionsVSAvoidactuator dimensioning
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Each actuator is dimensioned according to its specific local requirements - the force and velocity demands of its particular degree of freedom. This localized optimization allows smaller, less expensive actuators to be used where full performance is not needed, while still maintaining the capability to handle extreme conditions when required through coordinated actuation.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3316844B1Apparatus to apply forces in a three-dimensional space
Publication Date: 2022.05.18 ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL)
  • EP3316844B1 patent drawingFigure 1
  • EP3316844B1 patent drawingFigure 2
  • EP3316844B1 patent drawingFigure 3~4

AI summary

The present invention relates to a robotic system useful to unload an object/person from its weight. The robotic system is useful in locomotor rehabilitation programs and allows the manipulation of forces in a three-dimensional space with far lower actuator requirements and a much higher precision than prior-art systems. The apparatus combines passive and active elements to minimize actuation requirements while still keeping inertia to a minimum and control precision to a maximum. It requires minimal actuators and at the same time has a low inertia.