Electrostatic Foot Gesture Detection for Reliable Step Triggering

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing devices for monitoring user activity and step counting are not reliable in accounting for individual variations in physical conditions or movements, leading to inaccurate step counting due to unpredictable conditions such as short steps or arm movements, and require high computational load.

Innovation Solution

A system and method using an electrostatic charge variation sensor to detect specific gestures like upward and downward foot movements, generating a command signal to control device functionalities, with a processing unit that extracts significant parameters from the charge variation signal to differentiate between intended gestures and complex activities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If triaxial accelerometers and step recognition algorithms are used for step counting, then step counting functionality is provided, but accuracy deteriorates due to individual variations in physical conditions and movements

Engineering Contradiction:
Improvestep counting accuracyVSAvoidstep detection accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical acceleration-based detection system with an electrostatic field-based detection system. Instead of using triaxial accelerometers that measure mechanical acceleration, the invention uses sensors that detect variations in electrostatic field caused by foot movements, thereby substituting a mechanical measurement approach with an electrical field-based approach that is less sensitive to individual movement variations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the detection parameter from mechanical acceleration to electrostatic field variation. By measuring the change in electrostatic field strength caused by foot movements rather than relying on acceleration patterns, the system adapts to different user characteristics and movement styles, improving accuracy for individual users with varying physical conditions.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If sophisticated algorithms integrate various acquired data flows to determine output parameters, then measurement precision is improved, but computational load increases

Engineering Contradiction:
Improveactivity parameter accuracyVSAvoidcomputational energy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent extracts and isolates the specific signal component related to foot movements from the electrostatic field variations. By focusing detection on the particular pattern and characteristics of foot movement-induced electrostatic changes, the system separates the useful signal from background noise and other movements, reducing the need for complex computational algorithms to identify relevant patterns.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a simpler detection approach that captures only the essential electrostatic field variations caused by foot movements, rather than comprehensively analyzing all possible movement parameters. This partial detection approach provides sufficient accuracy for step counting while significantly reducing computational requirements compared to sophisticated multi-parameter analysis algorithms.

Inventive Principle:
Principle #16Partial or excessive action

3Adaptability or versatility

If electric field sensors are used to detect user activity, then alternative detection method is provided, but reliability deteriorates due to unpredictable conditions and complex activities

Engineering Contradiction:
Improvedetection method flexibilityVSAvoidgesture detection reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the electrostatic field detection into specific components related to foot movements. By analyzing particular characteristics of the electrostatic signal pattern that are unique to foot lifting and placing actions, the system distinguishes genuine step gestures from other body movements, thereby improving reliability while maintaining adaptability to different users and conditions.

Inventive Principle:
Principle #1Segmentation

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

This approach provides a reliable, economical, and low-computational-load method for controlling device functionalities based on user gestures, ensuring accurate step counting and activity monitoring by isolating specific signal components from background noise and complex movements.

Implementation Method 1

detecting as a consequence of this gesture a variation of the electrostatic charge of the user's body

Methodology Applied
Scientific EffectElectrostatic charge variation: Electrostatic Induction

Data Source

PatentEP3910923B1System and method for detecting upward and downward movements of a foot of a user with the aim of triggering a functionality of a device of the user, and user device
Publication Date: 2024.09.04 STMICROELECTRONICS SRL
  • EP3910923B1 patent drawingFigure 1
  • EP3910923B1 patent drawingFigure 2
  • EP3910923B1 patent drawingFigure 3

AI summary

System and method for controlling at least one functionality of an electronic device (4) on the basis of a gesture of a user, comprising: detecting, by means of a suitable sensor, a variation of electrostatic charge of the user during the execution of the gesture and generating a charge variation signal (SQ). The gesture includes moving at least one foot upward and, subsequently, downward. By means of a processing unit (2): acquiring the charge variation signal; detecting, in the charge variation signal, a characteristic identifying the gesture of moving the foot upward; detecting, in the charge variation signal, a characteristic identifying the gesture of moving the foot downward; and controlling the functionality of the electronic device (4) only in the event that both the first and the second characteristics have been detected.