Capacitive Detection Surface for Combined Touch and Pressure Sensing
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Solution Overview
Problem
Current capacitive detection systems for robotics require separate and costly sensors for detecting object approach/contact and pressure, leading to bulkiness, complexity, and interference issues.
Innovation Solution
A single sensor device with measurement and guard electrodes, where the electrodes are separated by an elastically modifiable distance, uses identical or substantially identical alternating electrical potentials to measure object approach/contact and pressure, minimizing bulkiness and complexity while reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate sensors for approach/contact detection and pressure detection are used, then detection functionality is complete, but device complexity and cost increase
Solution Approach 1:
The patent combines approach/contact detection and pressure detection into a single capacitive sensor system. The measurement electrode and guard electrode configuration allows both detection functions to be performed simultaneously by the same sensor structure, eliminating the need for separate sensors and reducing overall system complexity.
Solution Approach 2:
The capacitive sensor system is designed to perform multiple detection functions universally. The same measurement electrode can detect both the approach/contact of objects (through electrode-object capacitance) and the pressure applied (through electrode-guard capacitance), making the sensor multi-functional rather than dedicated to a single purpose.
2Adaptability or versatility
If separate sensors for approach/contact detection and pressure detection are used, then all parameters can be detected, but the device becomes bulkier
Solution Approach 1:
The patent merges approach/contact detection and pressure detection into a single integrated sensor unit. The measurement electrode and guard electrode are positioned within the same detection surface structure, allowing both detection capabilities to coexist in a compact configuration rather than requiring separate sensor modules that would increase device volume.
3Adaptability or versatility
If separate sensors for approach/contact detection and pressure detection are juxtaposed, then both functions are available, but mutual interference degrades sensor operation
Solution Approach 1:
The patent segments the detection functions into distinct electrical measurement paths within a unified sensor structure. The measurement electrode measures electrode-object capacitance for approach/contact detection, while the guard electrode measures electrode-guard capacitance for pressure detection. This segmentation of measurement paths eliminates mutual interference that would occur with physical juxtaposition of separate sensors.
Solution Approach 2:
The guard electrode acts as an intermediary element that enables pressure detection through electrode-guard capacitance without interfering with the measurement electrode's approach/contact detection. The guard electrode is electrically isolated and mechanically coupled to the detection surface in a way that allows it to sense pressure-induced deformations independently, serving as a mediator that separates the two detection functions while maintaining system integration.
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 simultaneous and unambiguous measurement of object approach/contact and pressure with improved detection performance and reduced costs compared to traditional dual-sensor configurations.
Implementation Method 1
measuring a first signal with respect to a value of an electrode-object capacitance
Implementation Method 2
measuring a second signal with respect to a value of an electrode-guard capacitance
Implementation Method 3
the electrodes are separated by a distance that is elastically modifiable locally, by a load exerted by said object on said detection surface
Data Source
AI summary
A device for detecting an object with respect to a detection surface including at least one measurement electrode and at least one guard electrode separated by a distance (D) that is elastically modifiable locally by a load exerted by the object on the detection surface; and structure for electrical polarization of the electrodes (V, E) arranged in order to: (i) apply to the measurement and guard electrodes one and the same first alternating electrical potential (Vg) so as to measure a first signal relating to an electrode-object capacitance (Ceo); and (ii) apply between the measurement and guard electrodes an alternating electrical potential difference (V1), so as to measure a second electrical signal relating to an electrode-guard capacitance (Ceg).A detection method utilizing the present detection device is also provided.