Multi-Sensor Displacement Validation on Curved Touch Surfaces

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Solution Overview

Problem

Integrating touch-sensitive inputs into complex systems, such as car dashboards, is challenging due to non-standard shapes and curved surfaces, making it difficult to reliably detect user input while maximizing space, especially in distinguishing valid displacements on sensing surfaces from invalid ones.

Innovation Solution

A sensing apparatus with a frame element and a displaceable element, equipped with multiple displacement sensor elements arranged at different spatial locations, uses processing circuitry to determine valid displacements by comparing displacement sensor output signals to pre-determined ratios, distinguishing between valid and invalid displacement loads applied to the sensing surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If touch-sensitive inputs are integrated into complex systems with non-standard shapes and curved surfaces, then space utilization and aesthetic appeal are improved, but the reliability of displacement detection deteriorates

Engineering Contradiction:
Improvespace utilizationVSAvoiddisplacement detection reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The sensing surface is divided into multiple zones with different displacement characteristics. By segmenting the surface and assigning different expected displacement ratios to different zones, the system can accurately detect valid displacements even on complex non-standard shapes and curved surfaces, thereby maintaining high space utilization while improving detection reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system pre-determines and stores expected displacement ratios for different zones of the sensing surface during the design phase. This preliminary action allows the system to quickly compare actual displacements against known valid patterns during operation, enabling reliable detection on complex surfaces without requiring real-time complex calculations.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If multiple displacement sensor elements are used to distinguish valid displacements, then detection accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvedisplacement detection accuracyVSAvoidsensor element quantity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Different zones of the sensing surface are assigned different expected displacement ratios based on their local geometric characteristics. This local quality approach allows the system to use multiple sensor elements effectively, improving measurement precision by considering the specific displacement behavior of each local zone rather than treating the entire surface uniformly.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system changes the parameter being measured from absolute displacement values to displacement ratios between different sensor elements. This parameter transformation simplifies the analysis by normalizing the data, allowing accurate detection of valid displacements while reducing the computational complexity of processing signals from multiple sensor elements.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If displacement ratios are compared to pre-determined values, then false detections are reduced, but processing requirements increase

Engineering Contradiction:
Improvefalse detection rateVSAvoidprocessing circuitry complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system replaces complex mechanical validation mechanisms with an electronic ratio-comparison approach. By substituting physical validation hardware with computational comparison of displacement ratios against pre-stored expected values, the system reduces false detections while keeping the processing circuitry relatively simple and efficient.

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

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 solution effectively discriminates between valid and invalid displacement loads on non-standard surfaces, enhancing the reliability of touch-sensitive inputs in complex environments like vehicle dashboards, ensuring accurate user input detection while optimizing space usage.

Implementation Method 1

a capacitive sensor element comprising the sensing surface and configured to sense changes in capacitive couplings between the sensing surface and a plurality of objects at different locations

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

a displacement sensor configured to detect changes in the displacement of the capacitive sensor element

Methodology Applied
Scientific EffectDisplacement sensing: Displacement

Data Source

PatentEP4204936B1Displacement sensing apparatus
Publication Date: 2024.10.16 TOUCHNETIX
  • EP4204936B1 patent drawingFigure 1~3
  • EP4204936B1 patent drawingFigure 4A~4B
  • EP4204936B1 patent drawingFigure 5~7

AI summary

Disclosed a sensing apparatus having a frame element and a displaceable element mounted relative to the frame element. The sensing apparatus comprises a plurality of displacement sensor elements each configured to provide a displacement sensor output signal indicative of a displacement between the frame element and the displaceable element, wherein the plurality of displacement sensor elements are arranged at different spatial locations relative to the displaceable element and configured to provide a displacement sensor output signal indicative of a displacement between the frame element and the displaceable element at the respective spatial location. The sensing apparatus further comprises processing circuitry configured to obtain the displacement sensor output signals from the plurality of displacement sensor elements and determine whether displacement of the displaceable element is a valid displacement by comparing at least the ratio between the displacement sensor output signals from a pair of the plurality of displacement sensor elements to one or more expected ratios for the pair of displacement sensor elements obtained in advance. Also disclosed is a device comprising the sensing apparatus, and a method for determining whether a displacement applied to a displaceable element mounted relative to a frame element is a valid displacement.