Capacitive Detection Surface With Elastic Electrode Gap Sensing

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Solution Overview

Problem

Current capacitive object detection systems in robotics require separate sensors for approach/contact and force/pressure detection, leading to increased complexity, cost, and interference issues.

Innovation Solution

A single sensor device with measuring and second electrodes, separated by an elastically modifiable distance, applies alternating potentials to measure both approach/contact and force/pressure signals using a single set of electrodes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate sensors are used for approach/contact detection and force/pressure detection, then detection functionality is complete, but device complexity and cost increase

Engineering Contradiction:
Improvedetection functionalityVSAvoidsensor system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines approach/contact detection and force/pressure detection into a single capacitive sensor system. The measurement electrode and second electrode form a capacitive structure that can detect both the approach/contact of objects and the force/pressure applied, eliminating the need for separate sensor systems and reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The capacitive sensor system performs multiple detection functions simultaneously. The same electrode configuration and measurement circuitry are used to detect both contact presence and force magnitude, making the sensor system universal and multi-functional rather than requiring dedicated sensors for each detection type.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If separate sensors are used for approach/contact detection and force/pressure detection, then detection coverage is complete, but manufacturing cost increases

Engineering Contradiction:
Improvedetection coverageVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges multiple detection capabilities into a single sensor assembly, reducing the total number of components that need to be manufactured and assembled. This consolidation lowers manufacturing costs while maintaining complete detection coverage for both contact and force measurements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The universal capacitive sensor design uses common structural elements and materials for both detection functions, simplifying the manufacturing process and reducing costs compared to producing and integrating separate specialized sensors.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If separate sensors are used for approach/contact detection and force/pressure detection, then detection capability is complete, but sensor interference occurs

Engineering Contradiction:
Improvedetection capabilityVSAvoidsensor interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

By combining both detection functions into a single capacitive sensor system, the patent eliminates the physical separation that would otherwise be needed between sensors, thereby eliminating mutual interference while maintaining complete detection capability through unified measurement methodology.

Inventive Principle:
Principle #5Merging (Combining)

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 solution reduces complexity and cost while improving detection performance by measuring both approach/contact and force/pressure signals with enhanced reliability and safety.

Implementation Method 1

measure a first electric signal relating to a capacitance, called electrode-object, between said measurement electrode and said object, representative of an approach and of a contact of said object with said detection surface

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3556017B1Device and method for detecting the approach and/or contact and pressure of an object in relation to a detection surface
Publication Date: 2021.01.06 FOGALE NANOTECH SA
  • EP3556017B1 patent drawingFigure 1a~1b
  • EP3556017B1 patent drawingFigure 1c~2
  • EP3556017B1 patent drawingFigure 3~4

AI summary

The invention relates to a detection device (300) comprising: a measuring electrode (106) and a second electrode (108) separated from each other by a distance (D) which is elastically locally modifiable by a pressure exerted by an object (102) on a detection surface (104); and control means (116) arranged so as to connect the electrodes (106, 108) to an alternating guard voltage (Vg) in order to measure a capacity representative of an approach and a contact, and to connect the second electrode (108) to a second voltage proportionate to the guard voltage (Vg) and having a different amplitude, or to the mass voltage (M), in order to measure a capacity representative of a pressure. The invention also relates to a detection method using such a detection device.