Unidirectional Exoskeleton Actuation for Lightweight Force Assistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exoskeletons face challenges in achieving a balance between being lightweight, providing high force/torque/power, maintaining comfort, and ensuring efficient energy conversion while minimizing interference with natural body motion.
Innovation Solution
The exoskeleton design incorporates unidirectional actuators, such as a brushless electric motor with a winch or belt mechanism, and sensors for precise control, allowing for compact, lightweight, and efficient force application while minimizing interference with natural joint motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If active exoskeletons use batteries and electric motors to provide high force and torque, then the force output capability is improved, but the device mass increases
Solution Approach 1:
The patent employs pneumatic actuators filled with compressed gas to generate force and torque. The pneumatic system uses a cylinder-piston mechanism where compressed gas expands to move the piston, providing the necessary force. This approach replaces traditional electric motors and batteries, achieving high force output with significantly reduced device mass, as the pneumatic components are lighter and do not require heavy power sources.
2Force
If the exoskeleton uses a mechanical joint in parallel with a biological joint to assist motion, then the force assistance is improved, but the device complexity increases
Solution Approach 1:
The exoskeleton is divided into modular segments, with each segment containing a mechanical joint parallel to a biological joint. This segmentation allows the complex system to be broken down into manageable units, each providing localized force assistance. The modular design simplifies the overall system by allowing independent optimization of each segment and facilitating easier assembly and maintenance.
Solution Approach 2:
The patent introduces a mechanical joint as an intermediary between the pneumatic actuator and the biological joint. This intermediary component translates the linear motion from the pneumatic piston into rotational motion that aligns with the biological joint's movement pattern. The mechanical joint acts as a mediator that coordinates the force application with the natural range of motion, reducing complexity in the control system.
3Weight of moving object
If the exoskeleton is designed to be lightweight and compact, then the device mass is reduced, but the force and torque output may be compromised
Solution Approach 1:
The patent utilizes parameter changes in the pneumatic system to optimize the balance between weight and force output. By varying the pressure, volume, and configuration of the pneumatic components, the system achieves high force output with minimal mass. The pneumatic cylinder dimensions, gas pressure, and piston surface area are carefully selected to maximize force while keeping the overall device lightweight and compact.
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 design achieves a compact, lightweight exoskeleton that provides powerful assistance with minimal bulk, maintains user comfort, and efficiently transfers energy, enhancing control and compatibility with natural body movements.
Implementation Method 1
The motor may be any type of motor, but is preferably brushless in configuration where its diameter is larger than its length
Implementation Method 2
The present invention also provides a mechanical joint in parallel with a biological joint. The exoskeleton device preferably includes an electric motor and a winch, chain, belt, cam transmission or other mechanism for providing unidirectional force.
Data Source
AI summary
The present invention is directed to an autonomous exoskeleton device that includes one or more actuators, one or more controllers, one or more sensors with one or more unidirectional transmissions. The present invention provides a mechanical joint in parallel with a biological joint. The exoskeleton device preferably includes and electric motor and winch, chain, belt, cam transmission or other mechanism for providing unidirectional force to assist rotation about the biologic joint. Moreover, a controller, a motor angle sensor, joint angle sensor and/or force sensor may be used for additional control and monitoring of the device. The motor may be any type of motor, but is preferably brushless in configuration where its diameter is larger than its length to provide a compact and lightweight exoskeleton device.