Wearable Action-Assist Device Kinetics Parameter Identification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wearable power-assist devices face challenges in providing effective assistance due to unknown kinetics parameters of individual wearers, leading to insufficient assistance for varying physical conditions and differences between assumed and actual wearer physiques, especially when shared devices are used.
Innovation Solution
Incorporating a biosignal detection unit, drive torque estimation, joint angle detection, and parameter identification to adjust the drive source's torque based on the wearer's specific kinetics parameters, allowing for personalized assistance without requiring dedicated devices for each user.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated power-assist device is prepared for exclusive use of every wearer, then the assisting force can be optimized for each individual, but the cost and complexity of the system increases significantly
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the kinetics parameters (weight, moment of inertia, coefficient of viscosity) based on detected wearer characteristics. The control unit modifies these parameters in real-time to match the actual wearer's physique, eliminating the need for dedicated devices while maintaining optimized assisting force for each individual.
2Ease of operation
If the kinetics parameters are set based on assumed wearer physique at initialization, then the device can be configured quickly, but the assisting force becomes inappropriate when the actual wearer differs from the assumed physique
Solution Approach 1:
The patent implements feedback by using sensors to detect actual wearer characteristics (such as joint angles, muscle activity, or body measurements) and continuously comparing these with the assumed physique parameters. The control unit then adjusts the kinetics parameters based on this feedback loop, ensuring the assisting force remains suitable despite differences between assumed and actual wearer physiques.
3Reliability
If the kinetics parameters are adjusted to match each individual wearer, then the assisting force becomes more suitable, but additional detection and control mechanisms are required
Solution Approach 1:
The patent applies universality by designing a single power-assist device with multi-functional capabilities. The device integrates detection units, control units, and adjustable kinetics parameters into one universal system that can adapt to any wearer. This eliminates the need for multiple dedicated devices while managing complexity through integrated design.
4Device complexity
If the device uses fixed kinetics parameters from initialization, then the control system remains simple, but the assisting force becomes too small or too large for wearers with different physiques
Solution Approach 1:
The patent applies dynamics by transforming the fixed kinetics parameters into dynamic, adjustable parameters. The control unit continuously modifies the weight, moment of inertia, and coefficient of viscosity based on detected wearer characteristics, enabling the device to adapt to different physiques while maintaining relatively simple control architecture through automated adjustment.
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 enables effective torque control that adapts to individual differences, ensuring sufficient assistance while minimizing the burden and incongruity caused by the device's weight and inertia, thus providing a more comfortable and efficient operation.
Implementation Method 1
a myoelectricity sensor (biosignal detection unit) which detects a myoelectricity signal accompanied with a wearer's muscular line activity
Data Source
AI summary
A wearable action-assist device includes a biosignal detection unit detecting a biosignal from a wearer, an action-assist wearing tool having a drive source supplying a torque acting on the wearer around each joint of the wearer as an axis of rotation, a control unit controlling the drive source to generate the torque according to the detected biosignal, a drive torque estimation unit estimating a drive torque generated by the drive source, a joint-angle detecting unit detecting an angular displacement of the joint, and a parameter identification unit identifying kinetics parameters concerned by substituting the estimated drive torque and the detected angular displacement into an equation of motion of an entire system including kinetics parameters intrinsic to the wearer. The control unit is configured to control the drive source according to a predetermined control method based on the equation of motion into which the identified parameters are substituted.