Foot Acceleration Signal Processing for Step Distance Accuracy

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Solution Overview

Problem

Existing systems for processing foot acceleration signals struggle with accuracy in determining step distance and user information due to errors induced by peak values associated with foot impact, which affect subsequent calculations such as speed and distance measurements.

Innovation Solution

A system comprising an acceleration sensor and a signal processing system that identifies and processes peak acceleration values to generate a smoother second acceleration signal, reducing errors by adjusting or averaging values around the peak, allowing for more accurate step distance determination and providing insights into running style and shoe characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If peak acceleration values associated with foot impact are included in the signal processing, then the system captures complete motion data, but measurement precision of step distance deteriorates due to errors induced by peak values

Engineering Contradiction:
Improvestep distance measurement precisionVSAvoidsignal accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent extracts and removes peak acceleration values associated with foot impact from the acceleration signal. The signal processing system identifies these peak values and excludes them from subsequent integration calculations, thereby eliminating the source of error that would otherwise compromise step distance measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter processing approach by selectively filtering acceleration signal values based on their magnitude characteristics. Peak values exceeding a predetermined threshold are identified and removed, transforming the raw signal into a cleaned signal suitable for accurate integration and step distance calculation.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If peak acceleration values are removed from the signal, then measurement precision improves, but loss of information occurs regarding impact characteristics

Engineering Contradiction:
Improvestep distance measurement precisionVSAvoidimpact characteristic information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the acceleration signal processing into two distinct pathways: one pathway removes peak values for accurate step distance calculation, while another pathway preserves these same peak values for analyzing impact characteristics. This segmentation allows both objectives to be achieved simultaneously without compromising either measurement precision or information completeness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary processing stage that separates the handling of peak acceleration values. The signal processing system acts as an intermediary that routes peak values to different processing streams - one for exclusion from integration and another for impact analysis - thereby preventing information loss while maintaining measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 system achieves more accurate step distance calculations and user information, such as running style and shoe performance, by smoothing the acceleration signal, thereby reducing errors and enhancing the reliability of fitness tracking data.

Implementation Method 1

at least one acceleration sensor measures the acceleration of a foot during a movement of the foot from a first position of the foot on a surface to a second position of the foot on the surface

Methodology Applied
Scientific EffectAcceleration measurement: Accelerometer

Data Source

PatentEP3112811B1System and method for processing a foot acceleration signal
Publication Date: 2019.02.27 EMBEDDED SENSOR SOLUTIONS BV
  • EP3112811B1 patent drawingFigure 1
  • EP3112811B1 patent drawingFigure 2
  • EP3112811B1 patent drawingFigure 3

AI summary

The disclosure relates to a system and method for pro-cessing a first acceleration signal. At least one acceleration sensor is provided for measuring acceleration of a foot during a movement of the foot from a first position of the foot on a surface to a second position of the foot on the surface and for generating the first acceleration signal comprising a plurality of acceleration values in response to measuring the acceleration. The system comprises a signal processing system configured to identify one or more acceleration values in the first acceleration signal associated with an impact of the foot on the surface and to process the identified one or more acceleration values to obtain a processing result. The processing result may comprise a step distance and/or user information relating to user performance and/or material characteristics.