Capacitance-Based Center of Gravity Detection for Wearable Motion Assist
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The centroid position detector devices using pressure-sensitive sensors have poor durability due to repeated deformation from the weight of the wearer, leading to potential fractures in the film-like conductive layers.
Innovation Solution
A centroid position detector device utilizing a load measuring part with a sheet-like elastic plate, upper and lower electrodes, and a capacitance detection mechanism that measures load changes based on capacitance variations, allowing for durable detection of center of gravity shifts even with electrode damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressure-sensitive sensors are used to detect load changes, then the centroid position can be detected, but the durability deteriorates due to repeated deformation causing film-like conductive layer fractures
Solution Approach 1:
The patent replaces the mechanical pressure-sensitive sensor system with a capacitance-based detection system. Instead of using film-like conductive layers that physically deform under pressure, the invention uses capacitive sensors that measure load changes through electrical field variations. This substitution eliminates the mechanical stress and fracture problems inherent in pressure-sensitive sensors while maintaining the ability to detect load changes for centroid position determination.
Solution Approach 2:
The patent changes the detection parameter from mechanical pressure to electrical capacitance. By measuring capacitance variations instead of physical pressure, the system avoids the durability issues of pressure-sensitive materials. The capacitance changes in response to load-induced distance variations between electrodes, providing a non-contact, wear-free measurement method that significantly improves reliability.
2Measurement precision
If pressure-sensitive sensors with film-like conductive layers are used, then load detection is achieved, but the device complexity increases due to the need for durable sensor construction
Solution Approach 1:
The patent replaces complex mechanical pressure sensor construction with simpler capacitive sensor architecture. Instead of layering fragile conductive films on flexible substrates, the invention uses straightforward capacitor structures (electrodes separated by dielectric material) that are inherently more robust and easier to manufacture without compromising measurement precision.
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 reliable detection of center of gravity shifts and significantly increases the durability of the centroid position detector device by using capacitance-based load measurement, which is less prone to damage from repeated deformation.
Implementation Method 1
the load measuring part is configured to measure the value of the load on the sole side of the foot of the person based on a capacitance that varies according to a shift of a weight of the person
Implementation Method 2
a sheet-like elastic plate having elasticity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Load measuring parts 50 and 52 are provided with reaction sensors 50a, 50b, 52a and 52b to measure loads at two positions, the tiptoe and the heel, on each sole of right and left feet of a wearing person 12. The reaction sensor 50a detects a reaction force to a load on a front side of the right foot (right tiptoe), the reaction sensor 50b detects a reaction force to a load on a rear side of the right foot (right heel), the reaction sensor 52a detects a reaction force to a load on a front side of the left foot (left tiptoe), and the reaction sensor 52b detects a reaction force to a load on a rear side of the left foot (left heel). The reaction sensors 50a, 50b, 52a and 52b are arranged to detect, based on a change of a capacitance, the loads on the right and left feet during a walk action. A change of the load accompanied with a shift of the weight and a contact between the wearing person's foot and the ground can be detected.