Steering Column Capacitive Controls With Haptic Contactless Sensing

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Solution Overview

Problem

Current capacitive control systems for automotive steering wheel columns are expensive, inaccurate, and complex to assemble, particularly when providing haptic responses to drivers, as they rely on force-sensing and conductive contact switches.

Innovation Solution

A capacitive control system with a contactless design using a support with rotational control elements and a printed circuit board with capacitive activating regions, where the control elements are haptically engaged with deformable arms and internal cams, allowing for different activation modes without direct contact, reducing complexity and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If force-sensing and conductive contact switches are used to provide haptic response, then haptic feedback is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvehaptic feedbackVSAvoidassembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces mechanical contact switches and force-sensing mechanisms with a capacitive sensing system. The control element changes electrical capacitance through displacement without mechanical contact, eliminating the need for complex mechanical haptic mechanisms while maintaining driver feedback through the capacitive coupling between the control element and the printed circuit board.

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

Solution Approach 2:

The patent introduces an insulating layer as an intermediary between the control element and the printed circuit board. This insulating layer enables capacitive coupling without direct electrical contact, allowing the system to achieve both contactless operation and haptic feedback through the deformation of the insulating layer and associated electrical signals.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If conductive contact switches are used, then control functionality is achieved, but oxidation and wear occur reducing reliability

Engineering Contradiction:
Improvecontrol functionalityVSAvoidresistance to oxidation and wear
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces conductive contact switches with a capacitive sensing mechanism where the control element varies electrical capacitance through displacement. This contactless approach eliminates direct electrical contact between moving and stationary components, preventing oxidation and wear while maintaining reliable control functionality for automotive applications.

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

3Reliability

If contactless capacitive design is used, then resistance to wear and oxidation is improved, but haptic response becomes less perceptible

Engineering Contradiction:
Improveresistance to wear and oxidationVSAvoidhaptic response
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the physical parameters of the insulating layer and capacitive structure to enable haptic feedback. By designing the insulating layer with specific mechanical properties and configuring the capacitive coupling, the system produces detectable electrical signals in response to driver input while maintaining contactless operation, thus preserving both reliability and haptic response.

Inventive Principle:
Principle #35Parameter changes

4Ease of operation

If traditional force-sensing mechanisms are used, then haptic feedback is provided, but manufacturing cost increases

Engineering Contradiction:
Improvehaptic feedbackVSAvoidmanufacturing cost
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The patent replaces expensive mechanical force-sensing mechanisms and haptic feedback components with a capacitive sensing system integrated into the printed circuit board. This approach uses standard capacitive sensing technology and insulating materials to provide both control functionality and haptic feedback, significantly reducing manufacturing costs while maintaining performance.

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

The system provides a robust, cost-efficient, and simple-to-assemble capacitive control system that offers reliable haptic feedback without short circuits or oxidation, enhancing driver interaction with vehicle controls like windscreen wipers and cruise control.

Implementation Method 1

change the distance and thus electrical capacitance between the first and the second capacitive activating regions

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3782287B1Capacitive control system, in particular a steering wheel column integrated module of an automotive vehicle
Publication Date: 2022.06.29 MERIT AUTOMOTIVE ELECTRONICS SYST S L U
  • EP3782287B1 patent drawingFigure 1
  • EP3782287B1 patent drawingFigure 2
  • EP3782287B1 patent drawingFigure 3~6

AI summary

The present invention relates to a capacitive control system (1), in particular a steering wheel column integrated module of an automotive vehicle, comprising a support (6), at least one control element (3, 4, 5) disposed displaceably within the support (6), at least one first capacitive activating region (81a-81e) adjacent to a second capacitive activating region (71a-71e) and disposed beneath and cooperating with said control element (3, 4, 5) to change the distance and thus electrical capacitance between the first (81a-81e) and the second (71a-71e) capacitive activating regions. In order to increase robustness of the capacitive control system (1) said at least one first capacitive activating region (81a-81e) is disposed at a metal, deformable arm (83) haptically engaged with said control element (3, 4, 5), wherein said haptical engagement is provided by a shaped projection (82) or recess of the arm (83) cooperating with at least one internal recess (32, 42, 52) or projection of said control element (3, 4, 5), and the distance between the first (81a-81e) and the second (71a-71e) capacitive activating regions remains greater than zero.