Vehicle Touchscreen Haptics With Force-Sensing Panel Alignment

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current control devices for vehicle passenger compartments fail to accurately distinguish between user intention and action, leading to imperfect haptic feedback, which can result in false detections and poor user experience due to the oblique orientation of touch screens during haptic feedback and the inability to measure applied force for modulating feedback.

Innovation Solution

A control device with a touch screen equipped with capacitive sensors and force sensors on the same substrate, using conductive tracks and nanoparticles in colloidal suspension to detect user intention and action, ensuring the touch screen remains aligned during haptic feedback and allowing for variable feedback intensity based on applied pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If a capacitive sensor is used to detect user intention, then the detection of user interaction is enabled, but the sensor cannot differentiate between intention and action, leading to false detections

Engineering Contradiction:
Improvedetection of user interactionVSAvoiddifferentiation between intention and action
Core Design Contradiction:
Difficulty of detecting and measuringVSMeasurement precision

Solution Approach 1:

The patent combines a capacitive sensor and a force sensor into a single integrated sensing system. The capacitive sensor detects changes in capacitance when a user approaches or touches the control element (intention), while the force sensor simultaneously measures the applied pressure (action). By merging these two sensing mechanisms, the system can distinguish between mere proximity and actual pressing actions, eliminating false detections while maintaining ease of interaction detection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control element is designed to perform multiple sensing functions through a unified structure. The same control element that responds to capacitive changes also transmits force to the force sensor, making it a multi-functional interface that can detect both intention (capacitive proximity) and action (force application) without requiring separate physical controls for each function.

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

2Difficulty of detecting and measuring

If a micro-switch is used to detect user action, then the action detection is enabled, but the panel becomes obliquely oriented during haptic feedback, reducing feedback quality

Engineering Contradiction:
Improvedetection of user actionVSAvoidquality of haptic feedback
Core Design Contradiction:
Difficulty of detecting and measuringVSEase of operation

Solution Approach 1:

The patent replaces the traditional micro-switch mechanical detection system with a force sensor that can detect applied pressure without requiring physical panel movement. The force sensor is integrated into the control element's substrate and measures force directly through electrical changes, eliminating the need for mechanical switches that cause panel obliquity during haptic feedback operations.

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

Solution Approach 2:

The force sensor acts as an intermediary between the user's finger pressure and the control system. Instead of requiring direct mechanical contact with a micro-switch that would cause panel tilting, the force sensor mediates the pressure detection through the control element's structure, allowing haptic feedback to be applied while maintaining panel alignment and feedback quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If the touch panel is allowed to move during haptic feedback, then the haptic effect is transmitted, but the panel becomes misaligned, causing poor haptic perception

Engineering Contradiction:
Improvetransmission of haptic effectVSAvoidalignment of touch panel
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent segments the control element into distinct functional layers: a front touch-sensitive layer, a force-sensing layer, and a haptic feedback layer. The haptic actuator is positioned behind the control element and transmits vibrations through the control element's structure without requiring the entire panel to move or become misaligned. This segmentation allows haptic effects to be transmitted effectively while maintaining proper panel alignment for accurate touch and force detection.

Inventive Principle:
Principle #1Segmentation

4Measurement precision

If pressure-sensitive sensors are used to detect action, then the force measurement is enabled, but the system cannot modulate haptic feedback according to applied force

Engineering Contradiction:
Improvemeasurement of applied forceVSAvoidmodulation of haptic feedback
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent implements a feedback loop where the force sensor continuously monitors the pressure applied by the user, and this force measurement is used to dynamically modulate the haptic feedback intensity. When the user applies greater pressure, the system detects this through the force sensor and adjusts the haptic feedback accordingly, creating an adaptive interaction where the feedback intensity corresponds to the user's input force. This feedback mechanism enables the system to provide variable haptic responses based on real-time force measurement.

Inventive Principle:
Principle #23Feedback

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 provides clear and perceivable haptic feedback, improving user experience by maintaining the touch screen in a consistent plane and modulating feedback intensity, thus enhancing the quality of haptic perception and reducing false detections.

Implementation Method 1

capacitive sensors, allowing the detection of intention

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

pressure-sensitive sensors... an assembly of conductive or semiconducting nanoparticles in colloidal suspension in an electrically insulating ligand, said assembly forming a force sensor

Methodology Applied
Scientific EffectPiezoresistive effect: Piezoresistive Effect

Implementation Method 3

actuators, such as electromagnetic actuators, connected to the interface module to transmit a vibration movement

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Data Source

PatentEP4111150B1Control device intended to control a function of a motor vehicle
Publication Date: 2024.11.20 NOVARES FRANCE
  • EP4111150B1 patent drawingFigure 1~3
  • EP4111150B1 patent drawingFigure 4~5
  • EP4111150B1 patent drawingFigure 6~7

AI summary

The invention relates to a control device (10) intended to control a function of a motor vehicle, the control device (10) comprising: - a touch screen element (12) comprising an external surface equipped with one or more control zones (18) each assigned to a specific function of the motor vehicle, the touch screen element (12) supporting one or more elementary sensors (20) each positioned in line with one of said control zones (18), said elementary sensor or sensors (20) being capable of generating at least one signal in response to an action performed by the user on at least one of said control zones (18), - at least one actuator (30) configured to provide a user with haptic feedback through a translational movement of the touch screen element (12) in a plane (P), referred to as the vibration plane, and in just one direction of travel (Dx), - a control unit configured to receive said at least one signal generated by said elementary sensor or sensors (20) and to control said at least one actuator (30) in response to said signal, wherein the control device (10) comprises supporting and guidance means (16) intended to keep the touch screen element (12) aligned in the vibration plane (P).