Capacitive Insole Sensing for Accurate Automated Footwear Lacing
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Solution Overview
Problem
Existing footwear technologies face challenges in accurately determining foot presence and orientation using sensors, which is crucial for activating automated lacing systems properly, while also being cost-effective and reducing device complexity.
Innovation Solution
A capacitive sensor system is integrated into the footwear, specifically in the arch and heel regions, to detect changes in electric fields and accurately determine foot presence and orientation. This system uses a modular design that allows for interchangeable lacing engines and provides tactile and visual feedback to the user.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional pressure sensors are used to detect foot presence, then foot presence can be detected, but the device complexity and cost increase
Solution Approach 1:
The patent replaces mechanical pressure sensors with a capacitive sensing system that uses electrical fields to detect foot presence. The control circuit measures capacitance changes between the insole and the foot, eliminating the need for complex mechanical sensor assemblies while maintaining detection accuracy.
Solution Approach 2:
The patent introduces capacitance as an intermediary measurement parameter. Instead of directly measuring mechanical pressure, the system measures electrical capacitance changes that occur when the foot contacts the insole, providing a simpler detection mechanism that reduces device complexity.
2Measurement precision
If multiple sensors are used to determine foot orientation, then detection accuracy improves, but manufacturing cost and assembly complexity increase
Solution Approach 1:
The patent makes the capacitive sensor system multi-functional by using the same capacitance measurement mechanism to detect both foot presence and foot orientation. The control circuit analyzes capacitance patterns from different insole regions to determine both whether the foot is present and how it is oriented, eliminating the need for separate sensor systems.
Solution Approach 2:
The insole is divided into multiple capacitive sensing zones that can independently measure capacitance. By segmenting the insole into regions with different capacitive characteristics, the system can determine foot orientation based on which zones show capacitance changes, providing accurate orientation detection with a single integrated sensor layer.
3Productivity
If automated lacing system is activated without accurate foot presence detection, then lacing can be initiated, but lacing may occur before foot is properly positioned
Solution Approach 1:
The patent performs preliminary foot presence and orientation verification before activating the automated lacing system. The control circuit continuously monitors capacitance changes and only initiates lacing when it detects a stable capacitance pattern indicating the foot is properly positioned, preventing premature lacing activation.
Solution Approach 2:
The system uses real-time feedback from capacitive sensor measurements to determine when to activate lacing. The control circuit monitors capacitance patterns and provides feedback control, only triggering the lacing mechanism when the feedback indicates proper foot presence and orientation, ensuring reliable activation timing.
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 capacitive sensor system effectively determines foot presence and orientation, enabling precise activation of automated lacing mechanisms, while reducing sensor costs and assembly complexity, and providing reliable operation and customization options.
Implementation Method 1
A capacitive sensor system is integrated into the footwear, specifically in the arch and heel regions, to detect changes in electric fields
Data Source
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AI summary
A foot presence sensor system for an active article of footwear can include a sensor housing configured to be disposed at or in an insole of the article, and a controller circuit, disposed within the sensor housing, configured to trigger one or more automated functions of the footwear based on a foot presence indication. In an example, the sensor system includes a capacitive or magnetic sensor configured to sense changes in a body's proximity to the sensor in footwear. Characteristics of the sensed proximity can be used to update an automated footwear function, such as an automatic lacing function, or can be used to determine a step count, foot strike force, a rate of travel, or other information about a foot or about the footwear.