Exoskeleton Knee Joint Self-Locking With Progressive Friction Control
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Solution Overview
Problem
Existing knee joint exoskeletons for rehabilitation require frequent manual or remote control for locking and unlocking, leading to potential manipulation errors, poor user experience, and inability to mimic the high bionics of human walking.
Innovation Solution
The exoskeleton joint self-locking mechanism uses a progressive friction force control system, where a rotating outward expanding locking member forms friction surfaces with the second base, allowing for gradual locking and unlocking of the knee joint, mimicking natural joint activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If manual or remote control locking mechanism is used, then locking function is achieved, but frequent human intervention is required leading to manipulation errors and poor user experience
Solution Approach 1:
The system uses sensors to detect user movement state and automatically controls the locking mechanism without requiring manual intervention. The control unit receives sensor signals and autonomously activates or deactivates the locking mechanism based on detected walking or standing states, making the system serve itself rather than requiring continuous human control
Solution Approach 2:
The system incorporates sensors that continuously monitor user movement and provide feedback to the control unit. This feedback loop enables the system to detect when the user is walking versus standing, and automatically adjust the locking state accordingly, creating a closed-loop control system that responds to real-time user conditions
2Ease of operation
If progressive friction force control is used, then smooth natural movement is achieved, but complex control system is required
Solution Approach 1:
The system replaces complex mechanical control mechanisms with an electronic control system. Instead of using intricate mechanical linkages to achieve progressive friction control, the invention uses electronic sensors, a control unit, and an actuator to regulate the friction force between the locking member and base, simplifying the overall system architecture while maintaining smooth movement control
Solution Approach 2:
The system dynamically adjusts the friction force parameter between the locking member and base by controlling the actuator's position. The control unit modulates the friction force based on sensor feedback, creating progressive locking and unlocking effects that mimic natural joint movement without requiring complex mechanical structures
3Power
If traditional motor groups or hydraulic systems are used, then powerful actuation is achieved, but large weight and size are required
Solution Approach 1:
The system extracts and eliminates heavy motor groups and hydraulic systems from the exoskeleton design. Instead of using these bulky power actuation systems, the invention employs a compact actuator that works in conjunction with a passive friction-based locking mechanism, removing unnecessary heavy components while maintaining sufficient actuation power for knee joint control
Solution Approach 2:
The system uses periodic activation of the actuator to control the friction force, rather than continuous high-power motor operation. The actuator is activated only when needed to adjust the locking state, allowing the exoskeleton to leverage the user's own movement energy while requiring minimal active power input from the system
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
This solution reduces power consumption, extends battery life, and enhances user safety and comfort by allowing smooth, natural movement of the knee joint, while eliminating the need for complex motor groups or hydraulic systems.
Implementation Method 1
a mutual friction surface is formed between the rotating outward expanding locking member on the first base and the inner wall of the second base
Data Source
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AI summary
The present invention provides an exoskeleton joint self-locking mechanism, a knee joint and a bionic rehabilitation robot, wherein the self-locking mechanism comprises a first base, a rotating outward expanding locking member, a second base and a locking driving member; the rotating outward expanding locking member comprises a first rotating frame and a second rotating frame, and outer sides of the first rotating frame and the second rotating frame have a first friction surface; one end of the first rotating frame is pivoted with one end of the second rotating frame; the second base is rotationally mounted on the first base, and an inner wall of the second base defines a second friction surface enclosing the first friction surface; the locking driving member applies/removes a force pushing away from free ends of the first rotating frame and the second rotating frame, to make the first friction surface close contact to lock/unlock the second friction surface. The present invention locks and unlocks the joint by controlling the friction force, which is more in line with the activity habits at the joint and safer.