Foot Sensor Stride Width Estimation via Joint Movement Decoupling
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Solution Overview
Problem
Existing techniques for estimating stride width during walking are inaccurate due to the influence of knee and hip joint movements, which affects the calculation of walking posture indices.
Innovation Solution
An estimation device and method that calculate the angle formed by the tip directions of the left and right feet using acceleration and angular velocity data from sensors on each foot, allowing for more precise estimation of stride width without being influenced by knee and hip joint movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the trajectory during walking is specified based on acceleration detected by a gait change determination device attached to the lumbar region, then the stride width can be calculated, but the trajectory cannot be obtained accurately due to the influence of the movements of the knees and hip joints
Solution Approach 1:
The invention divides the measurement system into multiple independent sensor units placed on each foot separately, rather than using a single device on the lumbar region. This segmentation allows each foot's movement to be measured independently, eliminating the cumulative error from knee and hip joint movements that affects trajectory accuracy when using a centralized lumbar-mounted device.
2Ease of operation
If a gait change determination device is attached to the lumbar region to detect acceleration, then the stride width can be estimated, but the measurement is influenced by knee and hip joint movements reducing accuracy
Solution Approach 1:
The invention uses the feet as intermediary measurement points instead of measuring directly from the lumbar region. By placing sensors on the feet, the system directly captures the actual foot movement and orientation, using the feet as mediators that are less affected by the complex biomechanics of knee and hip joints, thereby improving 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
Enables accurate estimation of stride width and subsequent fatigue assessment by using sensors in each shoe sole to measure acceleration and angular velocity, improving calculation accuracy and reducing the impact of joint movements.
Implementation Method 1
only by the acceleration and the angular velocity measured by a sensor device provided in each sole of both feet
Data Source
AI summary
An estimation device calculates an angle formed by a tip direction of a left foot and a tip direction of a right foot. The estimation device estimates a stride width indicating an interval between heels of the left foot and the right foot, based on the angle.