Steering Wheel Inductive Sensing for Vibration-Free Interface Detection

Solution Overview

Problem

Existing mechanical switches in vehicle steering wheel assemblies are prone to mis-triggers due to vibration, thermal expansion, and part tolerance variations, leading to undesirable noises and a compromised user experience.

Innovation Solution

The implementation of an inductive sensing system within the steering wheel assembly, utilizing inductive sensors and target surfaces to detect micrometer-level movements, eliminating the need for mechanical contacts and allowing for adjustable sensitivity and noise control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical switches with significant travel distance are used, then mis-triggers from vibration are avoided, but the appearance of the steering assembly is degraded and squeaks and noises are produced

Engineering Contradiction:

Improveavoid mis-triggersVSAvoidsqueaks and noises

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces mechanical switches with inductive sensors that detect the position of a target surface without physical contact. The inductive sensor system includes a sensor that generates an electromagnetic field and a target surface that interacts with this field, allowing detection of steering wheel position and button presses without mechanical contacts, thereby eliminating squeaks and noises while maintaining reliability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a target surface as an intermediary between the user input and the sensor system. This target surface moves with the vehicle interface and modulates the electromagnetic field of the inductive sensor, enabling detection of micrometer-level movements without direct mechanical contact between the sensor and the moving part

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If mechanical switches with significant travel distance are used, then mis-triggers from vibration are avoided, but the appearance of the steering assembly is degraded

Engineering Contradiction:

Improveavoid mis-triggersVSAvoidappearance

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The patent replaces mechanical switches with inductive sensors that detect the position of a target surface without physical contact. The inductive sensor system includes a sensor that generates an electromagnetic field and a target surface that interacts with this field, allowing detection of steering wheel position and button presses without mechanical contacts, thereby eliminating squeaks and noises while maintaining reliability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a target surface that can be integrated into the cosmetic housing or panel of the steering assembly. This target surface moves with the vehicle interface and can be made from thin, flexible materials that maintain the aesthetic appearance while enabling the inductive sensing function, eliminating the need for visible mechanical travel

Inventive Principle:

Principle #30Flexible shells and thin films

3Object-generated harmful factors

If inductive sensing is used, then mechanical contacts are eliminated reducing noise, but the system requires precise detection of micrometer-level movements

Engineering Contradiction:

Improvenoise reductionVSAvoidmicrometer-level detection

Core Design Contradiction:

Object-generated harmful factorsVSMeasurement precision

Solution Approach 1:

The patent utilizes changes in inductance parameters of the sensor in response to the position of the target surface. By monitoring the inductance variations caused by the movement of the conductive target surface through the electromagnetic field, the system can detect micrometer-level movements with high precision while maintaining a non-contact, noise-free operation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces a target surface as an intermediary between the user input and the sensor system. This target surface moves with the vehicle interface and modulates the electromagnetic field of the inductive sensor, enabling detection of micrometer-level movements without direct mechanical contact between the sensor and the moving part

Inventive Principle:

Principle #24Intermediary (Mediator)

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 enhances user experience by reducing noise, improving cosmetics, and providing adjustable sensitivity, while reducing the burden on vehicle service organizations through remote calibration capabilities.

Implementation Method 1

at least one inductive sensor adapted to generate a signal in response to changes in a measured inductance caused by a change in distance between the at least one inductive sensor and the at least one target surface

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS20240383432A1Inductive sensing for vehicle interfaces

Publication Date: 2024.11.21 TESLA INC

AI summary

A system for triggering a functionality of a vehicle. The system includes an inductive sensor, a vehicle interface, and a conductive target. The conductive target can be coupled to the vehicle interface and configured to move with the vehicle interface between a first position and a second position relative to the inductive sensor. The first position has a first inductance and the second position has a second inductance different than the first inductance. The system can further include a controller.