Steering Wheel Hand Detection Using Internal Light Reflection

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Solution Overview

Problem

Existing hand detection systems on steering wheels are either distracting to drivers or overly complex and prone to false detections, with mechanical systems causing discomfort and sensor-based systems increasing complexity and cost.

Innovation Solution

A light-based system that emits a signal from inside the steering wheel onto a partially transparent detection area on the wheel's surface, using a light sensor to detect changes in the reflected signal to determine if a hand is present, potentially combined with capacitive sensors for redundancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical vibration is used for hand detection, then hand detection reliability is improved, but driver comfort deteriorates due to distracting vibrations

Engineering Contradiction:

Improvehand detection reliabilityVSAvoiddriver distraction

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical vibration-based detection system with an optical detection system using light sources and light sensors. The light-based system detects hand presence through optical properties (light absorption, reflection, transmission) rather than mechanical vibrations, thereby eliminating the distracting vibrations while maintaining detection reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If capacitive sensors are used for hand detection, then detection reliability is improved, but device complexity increases due to multiple sensors and circuitry

Engineering Contradiction:

Improvedetection reliabilityVSAvoidsteering wheel complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent makes the detection areas serve dual functions: they act as both the sensing surface for hand detection and as light guides for the optical detection system. This integration eliminates the need for separate sensor components and circuitry, reducing device complexity while maintaining detection reliability through the optical properties of the detection areas.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If multiple capacitive sensors are distributed across the steering wheel surface, then hand position detection accuracy is improved, but manufacturing cost increases

Engineering Contradiction:

Improvehand position detection accuracyVSAvoidmanufacturing cost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent changes the detection parameter from electrical capacitance to optical properties (light absorption, reflection, transmission). By using light-based detection through the steering wheel surface, the system achieves hand position detection accuracy without requiring multiple complex sensor assemblies, thereby reducing manufacturing costs while maintaining measurement precision.

Inventive Principle:

Principle #35Parameter changes

4Measurement precision

If capacitive sensors are used for hand detection, then detection sensitivity is improved, but false detections increase due to electrical interference

Engineering Contradiction:

Improvedetection sensitivityVSAvoidfalse detection rate

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent substitutes the electrical field-based capacitive sensing with an optical field-based detection system. By using light sources and light sensors to detect hand presence through optical interactions (absorption, reflection, transmission), the system maintains high detection sensitivity while eliminating false detections caused by electrical interference and varying electrical properties of the user's hand.

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

Provides reliable and non-distracting hand detection with reduced complexity and cost, while minimizing false positives by using light signals and internal reflection analysis.

Implementation Method 1

at least one light source (3) adapted to emit an emitted signal of light so that the emitted signal is directed from inside the steering wheel (20) to at least one detection area (6) of a surface of the steering wheel, the detection area being at least partially transparent for the emitted signal

Methodology Applied

Scientific EffectLight transmission: Light

Implementation Method 2

at least one light sensor (8) adapted to detect a reflected signal, which is a part of the emitted signal that is reflected from the detection area (6) into the inside of the steering wheel

Methodology Applied

Scientific EffectLight reflection: Reflection

Data Source

PatentUS11891106B2System for hand detection on a steering wheel

Publication Date: 2024.02.06 IEE INT ELECTRONICS & ENG SA

AI summary

A system for hand detection on a steering wheel. The system includes: at least one light source adapted to emit an emitted signal of light so that the emitted signal is directed from inside the steering wheel to at least one detection area of a surface of the steering wheel, the detection area being at least partially transparent for the emitted signal; at least one light sensor adapted to detect a reflected signal, which is a part of the emitted signal that is reflected from the detection area into the inside of the steering wheel; and a detection unit coupled to the at least one light sensor and adapted to detect a hand of a user on the steering wheel based on a detection of the reflected signal.