Knee Joint Guide: 6-Bar Linkage for Self-Alignment and Walking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional knee joint mechanisms struggle to accommodate diverse knee joint shapes and require individual customization, leading to high costs and difficulty in commercialization due to increased degrees of freedom and power transmission issues.
Innovation Solution
A knee joint guide apparatus with a planar rigid body 6-bar linkage mechanism, comprising revolute and prismatic joints, allows for self-alignment and mechanical advantage change based on flexion angle, enabling a single product to support multiple users without complex customization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a knee joint mechanism is designed with self-alignment function to accommodate various knee joint shapes, then adaptability to multiple users is improved, but the device complexity and degrees of freedom increase making power and speed transmission difficult
Solution Approach 1:
The patent applies universality by designing a knee joint mechanism that can accommodate various knee joint shapes and instantaneous center of rotation paths without requiring individual customization. The mechanism uses a combination of revolute joints and prismatic joints arranged in a specific configuration that allows it to function universally across different users while maintaining self-alignment capability.
Solution Approach 2:
The patent segments the knee joint mechanism into distinct functional components: proximal and distal body links connected through a 6-bar linkage mechanism with specific revolute and prismatic joints. This segmentation allows each component to perform its specific function while collectively achieving the self-alignment and adaptability goals without excessive overall complexity.
2Reliability
If a knee joint mechanism is customized according to individual body type to avoid strain on the wearer, then comfort and reliability are improved, but manufacturing cost increases and commercialization becomes difficult
Solution Approach 1:
The patent achieves universality through a standardized 6-bar linkage mechanism that can be manufactured as a single product line. The mechanism's design allows it to adapt to different knee joint geometries through its inherent degrees of freedom, eliminating the need for expensive individual customization while maintaining comfort and strain reduction benefits for various users.
Solution Approach 2:
The patent utilizes parameter changes by allowing the mechanism's geometric parameters (link lengths, joint angles) to vary within certain ranges to accommodate different knee joint shapes. This enables the same basic mechanism design to serve multiple users effectively without requiring custom manufacturing for each individual, thus controlling production costs while maintaining reliability.
3Device complexity
If a simple revolute joint mechanism is used, then device complexity is reduced, but it cannot accommodate multiple knee joint shapes and instantaneous center of rotation paths
Solution Approach 1:
The patent introduces dynamics by transitioning from a simple fixed revolute joint to a dynamic 6-bar linkage mechanism with multiple revolute and prismatic joints. This dynamic configuration allows the mechanism to adapt its geometry in real-time based on the instantaneous center of rotation path, enabling it to accommodate various knee joint shapes while maintaining relative simplicity through planar motion constraints.
Solution Approach 2:
The patent applies dimensionality change by extending the mechanism from a single-degree-of-freedom revolute joint to a multi-degree-of-freedom planar mechanism. The addition of prismatic joints and multiple links introduces new dimensional capabilities that allow the system to handle variable instantaneous center positions while maintaining the simplicity of planar rigid body motion, avoiding the need for complex three-dimensional mechanisms.
Data Source
AI summary
Disclosed is a knee joint guide apparatus which can be driven even at any point on a plane in which an instantaneous rotation center of a knee joint can be positioned by a self-alignment function, and can also implement output performance required for a walking operation through a mechanical advantage change depending on a flexion angle. The knee joint guide apparatus includes: a proximal body link provided above a knee joint; a distal body link provided at a location corresponding to the proximal body link below the knee joint; and a planar rigid body 6-bar linkage mechanism including a plurality of revolute joints and a plurality of prismatic joints, and a plurality of links between the proximal body link and the distal body link to output a mechanical advantage depending on a flexion angle of the knee joint in movement of the knee joint with a self-alignment function.