Virtual Dual Spring Model for Adaptive Gait Assistance
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Solution Overview
Problem
Current motion assistance apparatuses for elderly individuals and those with joint problems, as well as military applications, lack effective mechanisms to dynamically adjust support and force distribution during walking, leading to inefficient assistance and potential discomfort.
Innovation Solution
A motion assistance apparatus featuring a proximal support and a distal support with a virtual dual spring-mass model, where the controller adjusts the modulus of elasticity of virtual springs based on contact sensors and walking speed to provide tailored support and force distribution, mimicking the natural gait cycle by using a combination of springs and dampers to assist heel-strike and push-off phases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed support structure is used in motion assistance apparatus, then the structure is simple and reliable, but the assistance cannot be dynamically adjusted to match natural gait patterns
Solution Approach 1:
The patent applies dynamics by transitioning from a fixed support structure to a dynamic virtual dual spring-mass model that continuously adapts its parameters (modulus of elasticity, damping coefficient) based on real-time gait phase detection and walking speed, enabling the apparatus to mimic natural human gait patterns while providing phase-specific assistance
Solution Approach 2:
The controller dynamically adjusts key parameters including the modulus of elasticity and damping coefficient of the virtual springs based on detected gait phase and walking speed, allowing the support characteristics to change adaptively throughout the gait cycle without requiring complex mechanical reconfiguration
2Ease of operation
If uniform support is provided throughout the gait cycle, then the device structure is simple, but it cannot effectively assist specific phases like heel-strike and push-off
Solution Approach 1:
The patent implements periodic action by detecting the gait phase (heel-strike, mid-stance, push-off) and applying phase-specific virtual spring parameters that mirror the natural periodicity of human walking, providing enhanced assistance during critical phases like heel-strike and push-off while maintaining simplicity through controller-based regulation
3Object-affected harmful factors
If the support stiffness is kept constant, then the apparatus is mechanically simple, but it cannot reduce impact effectively during heel-strike
Solution Approach 1:
The patent applies beforehand cushioning by detecting the approach of heel-strike through gait phase monitoring and pre-adjusting the virtual spring parameters (increasing damping coefficient and modulus of elasticity) before impact occurs, thereby providing proactive impact reduction rather than passive resistance
4Adaptability or versatility
If the apparatus uses a single spring model, then the structure is simple, but it cannot accurately mimic the dual-leg coordination of natural gait
Solution Approach 1:
The patent applies segmentation by dividing the gait model into two independent virtual springs (first and second virtual springs) that can be controlled separately, allowing each spring to independently manage the gait phase of one leg while maintaining coordination through the controller, thus accurately mimicking dual-leg walking patterns
Data Source
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AI summary
The invention relates to a motion assistance apparatus comprising: a proximal support configured to support a proximal part of a user; a distal support configured to support a distal part of the user, the distal support comprising a first portion and a second portion; a support assembly configured to connect the proximal support and the distal support, to adjust a separation distance between the proximal support and the distal support, and to adjust a rotation angle of the distal support; the support assembly comprising: a first spring configured to connect the proximal support and the first portion of the distal support; and a second spring configured to connect the proximal support and the second portion of the distal support. The invention further relates to a method of controlling such a motion assistance apparatus