Knee Joint Motion Assistance Apparatus with Curved Guide
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motion assistance technologies do not effectively replicate the natural motion of human joints, particularly the knee joint, leading to reduced user wearability and efficiency in assisting elderly or patients with joint problems during walking.
Innovation Solution
A motion assistance apparatus comprising a proximal frame, distal frame, force transmitting member, connecting member, and actuator that allows for 2-DOF motion, with a mechanism that includes a rotary body, wire, and slider to simulate knee joint movement, providing adaptive support and reducing the inertial moment of the actuator for improved energy efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing motion assistance technologies are used, then the apparatus can provide basic motion support, but it cannot effectively replicate natural knee joint motion, reducing user wearability and assistance efficiency
Solution Approach 1:
The patent implements a dynamic motion reproduction mechanism where the rotary body rotates to different angles corresponding to different phases of knee joint movement (flexion, extension, locking). This dynamic adjustment allows the apparatus to adapt to the natural kinematics of the knee joint throughout the walking cycle, effectively replicating the complex multi-degree-of-freedom motion patterns while maintaining user comfort and wearability
2Measurement precision
If a complex mechanism is used to simulate knee joint movement, then motion accuracy improves, but device complexity and actuator inertial moment increase, reducing energy efficiency
Solution Approach 1:
The patent segments the knee joint motion into distinct phases (flexion, extension, locking) and uses a rotary body with specific angular positions to represent each phase. This segmentation allows the complex continuous motion to be controlled through discrete rotational positions, simplifying the control mechanism while maintaining high motion accuracy. The force transmitting member then translates these segmented rotational positions into the corresponding linear and rotational movements needed to replicate knee joint behavior
Solution Approach 2:
The patent introduces a force transmitting member as an intermediary between the rotary body and the distal frame. This intermediary component converts the rotational motion of the rotary body into the complex combined motions (linear displacement, rotation, and angular changes) required to accurately simulate knee joint movement. By using this intermediary mechanism, the system achieves high motion accuracy without requiring a directly complex actuation system, thereby improving energy efficiency
3Use of energy by moving object
If the actuator inertial moment is reduced, then energy efficiency improves, but the ability to provide sufficient force for motion assistance may be compromised
Solution Approach 1:
The patent employs a curved guide surface on the proximal frame that works with the force transmitting member to provide mechanical advantage. As the force transmitting member moves along the curved guide surface, the geometry of the curve amplifies the force output while maintaining a compact actuator with low inertial moment. This curved mechanism allows the system to achieve high force transmission capability without requiring a large, high-inertia actuator, thereby maintaining energy efficiency
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
A motion assistance apparatus including a proximal frame configured to support a proximal part of a user, a distal frame configured to support a distal part of the user, and a force transmitting member slidably connected to the proximal frame, and rotatably connected to the distal frame is provided.