Adaptive-Capacitive Steering Wheel for Recalibration-Free Touch Sensing

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Solution Overview

Problem

Existing capacitive touch recognition systems in steering wheels require external evaluation units, necessitating recalibration upon replacement and are space-consuming, limiting their spatial resolution and efficiency.

Innovation Solution

A steering wheel with integrated electrodes and a non-volatile data storage unit, connected via a wireless transponder, allows for simplified calibration and efficient capacitive touch detection, utilizing an RC oscillator circuit and adjusting sensitivity based on material permittivity and geometry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If capacitive touch recognition is integrated into the steering wheel, then touch recognition capability is improved, but the electronic evaluation unit takes up additional space outside the steering wheel

Engineering Contradiction:

Improvetouch recognition capabilityVSAvoidspace occupied by electronic evaluation unit

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The system is divided into two segments: the steering wheel assembly containing electrodes and a non-volatile data storage unit, and an external electronic evaluation unit. This segmentation allows the steering wheel to maintain touch recognition functionality while minimizing the space occupied by the evaluation unit, as only essential components remain integrated.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A non-volatile data storage unit serves as an intermediary between the steering wheel and the external electronic evaluation unit. It stores parameters associated with the steering wheel rim material's permittivity, enabling the external unit to perform accurate touch recognition without requiring a large integrated processing system.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the steering wheel is replaced, then new steering wheel functionality is achieved, but recalibration is required due to changed permittivity of materials

Engineering Contradiction:

Improvesteering wheel replaceabilityVSAvoidrecalibration time

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

Parameters associated with the steering wheel rim material's permittivity are pre-stored in a non-volatile data storage unit integrated into the steering wheel itself. When the steering wheel is replaced, the new wheel's parameters are automatically read by the electronic evaluation unit, eliminating the need for manual recalibration and reducing calibration time to nearly zero.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The steering wheel performs self-identification by storing its own material parameters in an integrated non-volatile data storage unit. The electronic evaluation unit automatically reads these parameters, allowing the system to adapt to the new steering wheel without external intervention or time-consuming recalibration procedures.

Inventive Principle:

Principle #25Self-service

3Measurement precision

If electrodes are integrated into the steering wheel rim, then touch detection precision is improved, but the construction space requirement increases

Engineering Contradiction:

Improvetouch detection precisionVSAvoidconstruction space

Core Design Contradiction:

Measurement precisionVSVolume of moving object

Solution Approach 1:

Electrodes are integrated into the steering wheel rim structure itself, utilizing the existing rim geometry and thin film structures. This approach maintains high touch detection precision while minimizing additional construction space, as the electrodes are embedded within the rim rather than adding separate bulky components.

Inventive Principle:

Principle #30Flexible shells and thin films

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 seamless integration and calibration of capacitive touch recognition, enhancing spatial resolution and reducing the need for external units, thus improving detection accuracy and efficiency.

Implementation Method 1

at least one electrode, which is integrated into the steering wheel rim, for the capacitive detection of a touch on the steering wheel rim

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

detect, based on an associated change in measuring capacitance and depending on at least one predetermined parameter, a touch on the steering wheel rim

Methodology Applied

Scientific EffectCapacitance measurement: Capacitance

Data Source

PatentUS12606229B2Steering wheel with adaptive-capacitive touch recognition, an associated assembly and motor vehicle

Publication Date: 2026.04.21 PREH GMBH

AI summary

A steering wheel for a motor vehicle is presented. The steering wheel includes a steering wheel hub configured for the detachable attachment to a steering shaft of the motor vehicle; a steering wheel rim fixed to the steering wheel hub; at least one electrode, which is integrated into the steering wheel rim, for the capacitive detection of a touch on the steering wheel rim; an electrically conductive connection disposed outside the steering wheel to apply an electrical measuring potential for touch detection to the electrode, and to detect the touch on the steering wheel rim; a non-volatile data storage unit on or in the steering wheel, wherein the non-volatile data storage unit is in each case configured or developed to be read out by a reading unit disposed outside the steering wheel and connected to the electronic evaluation unit in a data-transmitting manner.