Powered Elbow Exoskeleton With Glove-Sensed Bidirectional Assist
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing upper-limb exoskeletons primarily focus on unidirectional support for the shoulder, neglecting the need for bi-directional assistance at the elbow joint, especially for dynamic lifting tasks, and lack effective control mechanisms for realistic working environments.
Innovation Solution
A powered elbow exoskeleton with bi-directional actuation, incorporating a battery pack, controller housing, and motor housings with Bowden cables, coupled to upper and lower arm portions, and a control strategy using pressure sensors in gloves to determine the direction and magnitude of assistance based on finger and palm pressure distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If passive exoskeletons with spring mechanisms are used for unidirectional support, then shoulder support during overhead tasks is improved, but bi-directional assistance and adaptability for dynamic tasks are limited
Solution Approach 1:
The patent transitions from passive spring mechanisms to an active powered exoskeleton with motors that can dynamically adjust support in both flexion and extension directions. The system uses sensors to detect elbow joint state and actively provides assistance in either direction based on real-time task requirements, enabling adaptability for dynamic lifting tasks above and below shoulder height.
Solution Approach 2:
The exoskeleton is designed to perform multiple functions: providing support during overhead tasks, assisting during below-shoulder lifting, and adapting to various dynamic task conditions. The single device integrates bidirectional actuation capabilities to handle diverse work scenarios, making it universally applicable to different manual handling tasks.
2Adaptability or versatility
If active systems with motor actuation are implemented, then bi-directional assistance for dynamic tasks is improved, but device complexity and control difficulty increase
Solution Approach 1:
The exoskeleton incorporates sensors that automatically detect the user's elbow joint state, task conditions, and required assistance direction. The system self-regulates its actuation based on sensor feedback without requiring complex external control interfaces or secondary operators, simplifying the control architecture while maintaining adaptability.
Solution Approach 2:
The system uses sensors to continuously monitor elbow joint position, user effort, and task requirements, then adjusts motor actuation in real-time based on this feedback. This closed-loop control enables the exoskeleton to adapt to dynamic tasks while using relatively simple control logic compared to open-loop systems.
3Device complexity
If exoskeletons are designed for restricted range of motion with unidirectional support, then device simplicity is maintained, but functionality for dynamic lifting tasks spanning above and below shoulder is limited
Solution Approach 1:
The exoskeleton employs dynamic range of motion adjustment through powered actuation rather than fixed mechanical constraints. The motor-driven system can accommodate various elbow angles and lifting trajectories within a natural range of motion, allowing the device to adapt to different task requirements without complex mechanical reconfiguration.
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 exoskeleton provides effective bidirectional assistance, reducing muscle strain and enhancing endurance by up to 55% and increasing the number of lifts by 140%, while maintaining comfort and minimizing protrusion and weight on the arms.
Implementation Method 1
The cable sheath may have a tensioning apparatus (e.g., a barrel screw), that tensions the sheath relative to the inner cable
Implementation Method 2
The linear, structural members of the upper and lower portions are coupled together at their ends by rotational bearing
Data Source
AI summary
A powered elbow exoskeleton for assistance in the lifting and movement of objects is disclosed. The device has control and motor components arranged on a hip belt, and force is transmitted from motors to pullies arranged laterally to a user's elbow by cables. A controller actuates the pullies to provide extension and flexion torque to a hinged assembly having an upper arm portion and a forearm portion. The device includes pressure sensors in an instrumented glove to measure pressure being exerted by the user's finger(s) and palm(s). The sign of the difference between finger pressure and palm pressure is determined and used to determine the direction of assistive torque provided by the device.