Vehicle Sensor Series Circuit for Reliable Input Recognition

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Solution Overview

Problem

Existing motor vehicle door lock systems with capacitive sensors have high manufacturing complexity and costs due to complex wiring, and suffer from unreliable input recognition.

Innovation Solution

A sensor device with multiple sensor sections connected in a series circuit, including at least two capacitive components, where the sensor sections interact with operators to control vehicle functions, utilizing capacitive and resistive components to reliably detect input through changes in capacitance and damping behavior.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple capacitive sensors are used with separate evaluation circuits, then input recognition capability is improved, but manufacturing complexity and wiring complexity increase

Engineering Contradiction:
Improveinput recognition reliabilityVSAvoidwiring complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple sensor sections are connected in series between two capacitive components, merging multiple sensing functions into a single integrated circuit path. This eliminates the need for separate evaluation circuits for each sensor and significantly reduces wiring complexity while maintaining the ability to distinguish inputs from different sensor sections through capacitance ratio evaluation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The two capacitive components serve multiple functions: they act as reference elements for capacitance comparison, form part of the series circuit for all sensor sections, and enable differentiation of sensor inputs through their capacitance ratio. This universal application of the capacitive components reduces the overall component count and simplifies the system architecture.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple capacitive sensors with separate evaluation circuits are implemented, then sensor functionality is improved, but manufacturing costs increase

Engineering Contradiction:
Improvesensor functionalityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The series connection of multiple sensor sections between two capacitive components merges multiple sensing functions into a single integrated circuit path. This eliminates the need for separate evaluation circuits for each sensor and significantly reduces wiring complexity while maintaining the ability to distinguish inputs from different sensor sections through capacitance ratio evaluation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of using multiple complex capacitive sensor modules each with their own evaluation circuit, the invention uses a single evaluation circuit that evaluates the capacitance ratio of two capacitive components. This simplified 'copy' of the sensing function achieves the same versatility at lower manufacturing cost.

Inventive Principle:
Principle #26Copying

3Reliability

If traditional capacitive sensor systems are used, then sensing capability is achieved, but input recognition reliability is insufficient

Engineering Contradiction:
Improveinput recognition reliabilityVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the evaluation parameter from absolute capacitance values to the ratio of capacitance values between two capacitive components. This parameter transformation significantly improves input recognition reliability because the ratio remains stable even when individual capacitance values drift due to temperature, aging, or manufacturing tolerances, while the system structure remains relatively simple.

Inventive Principle:
Principle #35Parameter changes

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 solution simplifies manufacturing, reduces costs, and enhances the reliability of input recognition by using a series circuit with capacitive and resistive components to accurately determine sensor section actuations and differentiate between commands.

Implementation Method 1

capacitive sensor sections that register a change in capacitance due to a human hand approaching the door handle and the sensor device

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

One parameter from which this change can be read is the damping behavior of the capacitive components

Methodology Applied
Scientific EffectDamping: Damping

Data Source

PatentEP1905655B1Sensor device for vehicles
Publication Date: 2010.11.10 HUF HÜLSBECK & FÜRST GMBH & CO KG
  • EP1905655B1 patent drawingFigure 1~2

AI summary

The device (8) has a set of sensor sections (9) arranged at connecting points of a vehicle, where the sections are connected with each other in an electric series connection (10). Two capacitive components (11, 12) are arranged in the series connection, where the sections lie between the capacitive components, which are formed as capacitors. The sections are designed as electrodes, and an electric resistor (15) is arranged between the sections. A control device is additionally connected with electric connecting points of the components, where the device is connected to the control device. An independent claim is also included for a method for detecting signal input at vehicles.