Power Generating Leg Torque Regeneration and Control
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Solution Overview
Problem
Existing power generating leg technologies do not effectively convert walking mechanical power into electrical power across various terrains and phases of movement, such as ascending and descending stairs, while also providing assistance and energy storage.
Innovation Solution
A power generating leg with a torque generator and power unit that operates in regeneration, utilization, and dissipation modes, utilizing hydraulic and electric components to convert mechanical power into electrical power, store it, and control torque based on movement phases, with sensors and signal processors managing energy flow and resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a power generating leg converts mechanical power into electrical power during walking, then energy is generated for storage or use, but the device complexity increases due to multiple modes and components
Solution Approach 1:
The torque generator is designed to perform multiple functions: it can operate in power generation mode to convert mechanical energy to electrical energy, in power utilization mode to assist leg movement, and in dissipation mode to control unwanted motion. This multi-functionality allows a single device to address multiple needs without requiring separate systems for each function, thereby managing complexity while improving energy utilization
Solution Approach 2:
The system dynamically switches between different operational modes (generation, utilization, dissipation) based on real-time detection of leg movement phase, terrain, and energy storage status. The signal processor continuously monitors sensors and adjusts the torque generator's function accordingly, enabling adaptive operation that optimizes energy conversion while managing system complexity through intelligent control
2Ease of operation
If the torque generator provides assistance during ascent, then muscle stress is reduced, but energy is consumed from storage rather than generated
Solution Approach 1:
The system uses sensors to detect leg movement phase, terrain conditions, and energy storage levels, then the signal processor uses this feedback to determine when to switch between generation and utilization modes. During ascent, the system monitors energy availability and terrain difficulty to decide whether to draw from storage for assistance or to generate energy during the stance phase, creating a closed-loop control that balances assistance needs with energy conservation
Solution Approach 2:
The torque generator's operational parameters are dynamically adjusted based on detected conditions. During ascent on level ground with sufficient energy storage, the system switches to utilization mode with specific torque parameters to provide assistance. When terrain becomes more challenging or energy is low, the system changes parameters to prioritize energy generation during stance phase, adapting its behavior to current needs
3Adaptability or versatility
If the system operates in multiple modes (generation, utilization, dissipation), then functionality is enhanced, but control complexity increases
Solution Approach 1:
The control system is segmented into distinct functional modules: sensors detect specific parameters (movement phase, terrain, energy levels), the signal processor analyzes this data and determines optimal mode, and the torque generator executes the appropriate function. This segmentation allows each component to handle a specific aspect of control, reducing overall complexity while maintaining multi-mode functionality across different terrains and movement phases
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
The solution efficiently converts mechanical power into electrical power during stance phases, especially when descending, and provides assistance during ascent, while storing energy for later use, enhancing the functionality of orthotic and prosthetic legs.
Implementation Method 1
A torque generator 213 is configured to impose a torque that affects the movements of thigh link 103 and shank link 105 relative to each other. A power unit 215 coupled to torque generator 213 is configured to cause torque generator 213 to convert a portion of the power associated with the product of the generated torque and the angular velocity of shank link 105 and thigh link 103 relative to each other into electrical power
Implementation Method 2
Two hydraulic torque generators are coupled to each of the knee joints. A power unit, capable of providing power, is coupled to the torque generators. The power unit includes a first hydraulic path between a fluid reservoir and each of the hydraulic torque generators, said first hydraulic path comprising a hydraulic pump connected in series with a pump isolating valve, said hydraulic pump being rotatably coupled to an electric motor
Data Source
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AI summary
A power generating leg, configurable to be coupled to a person's lower limb, comprising a thigh link, a shank link, a knee mechanism, a torque generator, and a power unit The knee mechanism is connected to said thigh link and said shank link, and allows movements of said thigh link and said shank link relative to each other The torque generator is configured to generate torque between said shank link and said thigh link The power unit is coupled to said torque generator, and configured to cause said torque generator to generate torque In a power regeneration mode, said power unit causes said torque generator to generate a torque that opposes the angular velocity of said thigh link and said shank link and said power unit converts a portion of the power associated with the product of said torque into electrical power to be stored in a storage device.