Steering Wheel Grip Sensor with Conductive Member

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Solution Overview

Problem

Conventional grip sensors for steering wheels experience degradation in detection sensitivity when a decorative or functional component, such as a finisher or garnish, is mounted to the wheel, leading to inconsistent detection of occupant contact across the rim surface.

Innovation Solution

An occupant information detection sensor for a steering wheel is designed with a sensor electrode embedded in the rim body and a conductive member located on the surface of the mounting component, which is electrically connected or capacitively coupled with the sensor electrode, ensuring uniform detection sensitivity regardless of the presence of decorative or functional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a mounting component (decorative or functional) is mounted to the steering wheel rim, then the steering wheel can be enhanced with additional features, but detection sensitivity of the grip sensor is degraded at the mounted portion

Engineering Contradiction:

Improvesteering wheel functionalityVSAvoiddetection sensitivity

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The grip sensor is divided into multiple independent sensor wires positioned at different locations on the rim. Each sensor wire independently detects grip at its specific position, allowing the system to maintain detection capability even when mounting components are present at certain locations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A conductive member is introduced as an intermediary element between the sensor wire and the mounting component. This conductive member is positioned between the sensor wire and the mounting component to maintain electrostatic capacitance detection capability, preventing the mounting component from blocking the detection field.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If a mounting component is mounted to the rim body, then the steering wheel can have decorative or functional enhancements, but the electrostatic capacitance detection is blocked leading to inconsistent contact detection

Engineering Contradiction:

Improvesteering wheel customizationVSAvoidcontact detection consistency

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The rim is divided into multiple detection zones with separate sensor wires positioned at different angular locations. This segmentation ensures that if one sensor is blocked by a mounting component, other sensors continue to provide reliable detection, maintaining overall system reliability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the rim are equipped with different sensor configurations based on local requirements. Areas with mounting components have conductive members positioned to maintain detection capability, while areas without mounting components use standard sensor configurations.

Inventive Principle:

Principle #3Local quality

3Measurement precision

If the sensor wire is positioned close to the rim surface for high sensitivity, then detection sensitivity is improved, but mounting components will block the detection field

Engineering Contradiction:

Improvedetection sensitivityVSAvoidmounting component compatibility

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

A conductive member serves as an intermediary between the sensor wire and mounting component. The sensor wire can be positioned close to the rim surface for high sensitivity, while the conductive member placed between the sensor wire and mounting component prevents the mounting component from blocking the electrostatic detection field.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The detection system transitions from a single-plane detection approach to a multi-dimensional configuration. The sensor wire, rim surface, and conductive member are arranged in three-dimensional space, allowing the sensor to detect grip forces through the conductive member rather than being blocked by it.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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 configuration enhances detection sensitivity by maintaining consistent contact detection across the steering wheel rim, even when decorative or functional components are mounted, thereby preventing sensitivity degradation.

Implementation Method 1

the conductive member being capacitively coupled with a portion of the sensor electrode

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

electrostatic capacitance is generated between a vehicle and the sensor wire. When a person's hand comes into contact with the steering wheel, electrostatic capacitance is also generated between the hand and the sensor wire

Methodology Applied

Scientific EffectElectrostatic capacitance: Electrostatics

Data Source

PatentUS10677950B2Occupant information detection sensor for steering wheel

Publication Date: 2020.06.09 PANASONIC AUTOMOTIVE SYST CO LTD

AI summary

Rim of steering wheel has a rim body and mounting component mounted to the rim body so as to be exposed from a portion of the rim body. Occupant information detection sensor for a steering wheel disposed in rim includes: sensor wire disposed in the rim body; and conductive member located on at least a surface side of mounting component and electrically connected or capacitively coupled with a portion of sensor wire.