Hip Joint Link Apparatus Four-Bar Mechanism Single Actuator
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Solution Overview
Problem
Existing wearable robots require multiple actuators to assist varying moments at the hip joint during different gait phases, which increases complexity and cost, while existing solutions fail to efficiently utilize fewer actuators to provide all necessary moments.
Innovation Solution
A hip joint link apparatus with a four-bar linkage structure incorporating multiple revolute joints and links, allowing a single actuator to transmit input moments into desired output directions, thereby assisting flexion, extension, abduction, and adduction moments during walking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple actuators are used to assist all hip joint moments during walking, then all required moments (flexion, extension, abduction, adduction) can be provided, but the number of actuators increases and device complexity increases
Solution Approach 1:
The patent applies multi-functionality by enabling a single actuator to perform multiple functions through the four-bar linkage mechanism. The mechanism transforms one input moment into multiple output moments (flexion, extension, abduction, adduction) that would traditionally require separate actuators, allowing one actuator to replace multiple actuators while maintaining all required hip joint assistance functions
Solution Approach 2:
The four-bar linkage mechanism serves as an intermediary between the single actuator and the hip joint. It mediates the transmission of force by receiving input from the actuator and distributing it to produce multiple moment components, effectively acting as a force transformer that enables one actuator to control multiple degrees of freedom
2Device complexity
If one actuator per leg is used to simplify the design, then device complexity is reduced, but the ability to assist all varying moments during different gait phases is compromised
Solution Approach 1:
The patent applies parameter changes by utilizing the geometric parameters of the four-bar linkage (link lengths, joint positions) to transform the single actuator's input moment into varying output moments. By carefully designing these geometric parameters, the mechanism can generate the appropriate moment magnitudes and directions for different gait phases, enabling one actuator to adapt to varying moment requirements without increasing actuator count
3Adaptability or versatility
If a four-bar linkage structure with multiple revolute joints is implemented, then moment transformation capability is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the complex moment transformation function into separate modular components: multiple revolute joints and multiple links. Each joint and link is designed as an independent, standardized module that can be manufactured separately and then assembled, reducing overall manufacturing complexity while maintaining the sophisticated moment transformation capability of the complete four-bar linkage system
Data Source
AI summary
An embodiment of the present invention provides a hip joint link apparatus including: an upper body link fixed to an upper body of a wearable robot, and a hip joint jointer linking a thigh link linked to a thigh of the wearable robot, wherein the hip joint jointer has a four-revolute joint structure including a plurality of revolute joints and a plurality of links; an arbitrary input moment to the hip joint jointer is changed to an output moment in a predetermined direction based on a state of being transmitted to the plurality of links through the plurality of revolute joints; and the hip joint jointer assists a flexion moment, an extension moment, an abduction moment, and an adduction moment.