Capacitive Sensing with Object-Specific AC Polarization Frequencies

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Solution Overview

Problem

Current capacitive sensing devices in robots are unable to discriminate between a human operator and other objects, or between different objects in their environment, limiting their ability to adapt behavior accordingly.

Innovation Solution

A method and device that utilize capacitive electrodes and detection electronics to selectively detect surrounding objects by polarizing them at different alternating electric potentials, allowing for discrimination based on frequency, enabling the device to distinguish between objects and adapt behavior accordingly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional capacitive detection is used to detect surrounding objects, then the presence of objects can be detected, but the ability to discriminate between different objects (such as human operator vs. other objects) is lost

Engineering Contradiction:
Improveobject discrimination capabilityVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by varying the polarization frequency applied to different objects. Specifically, the human operator is polarized at a first frequency while other objects are polarized at a second frequency, allowing the detection device to distinguish between them by detecting signals at their respective frequencies. This frequency-based parameter differentiation enables precise object discrimination without requiring complex additional hardware.

Inventive Principle:
Principle #35Parameter changes

2Loss of information

If multiple objects are polarized at the same potential, then the detection system remains simple, but the ability to selectively detect and discriminate specific objects is reduced

Engineering Contradiction:
Improveobject identity informationVSAvoidenergy consumption for polarization
Core Design Contradiction:
Loss of informationVSUse of energy by stationary object

Solution Approach 1:

The patent implements periodic action by applying alternating polarization signals at different frequencies to different objects. The human operator receives a periodic polarization signal at a first frequency, while other objects receive periodic signals at a second frequency. This periodic, frequency-modulated approach allows the detection device to selectively extract information about specific objects by tuning to their respective frequencies, preserving object identity information while managing energy consumption through efficient signal modulation.

Inventive Principle:
Principle #19Periodic action

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 the capacitive detection device to accurately discriminate between objects, including humans and other environmental objects, allowing for personalized behavior adjustments and improved safety features.

Implementation Method 1

polarization of a first surrounding object at a first alternating electrical potential, different from a ground potential, and different from an electrical potential of at least one second surrounding object, at least at a first frequency; and determination of a first discriminating signal representative of a capacitance, called electrode-object capacitance, seen by said at least one measuring electrode, at said first frequency

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Data Source

PatentEP3909133B1Method and device for discriminatory capacitive detection, and apparatus provided with such a device
Publication Date: 2024.03.06 FOGALE SENSORS
  • EP3909133B1 patent drawingFigure 1~2a
  • EP3909133B1 patent drawingFigure 2b~3b
  • EP3909133B1 patent drawingFigure 4~5b

AI summary

The invention relates to a method for the capacitive detection of nearby objects (102, 104) possibly located in the surroundings of an apparatus provided with a capacitive detection device (100), comprising what is called a discriminatory detection step, comprising the following operations: - biasing a first nearby object (102) at a first alternating potential (V1), different from a ground potential (M) and from the potential of at least one second nearby object (104), at a first frequency (F1); and - determining a first discriminatory signal representative of a capacitance, called electrode-object capacitance, seen by said at least one measurement electrode, at said first frequency (F1).