Vehicle Door Touch Sensor Control for Rain False-Touch Prevention

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Solution Overview

Problem

Capacitive touch sensors in vehicle door handles can incorrectly sense rainwater as a human touch, leading to vehicle battery discharge and unintentional unlocking, due to ineffective directionality in sensing the smart key's approach.

Innovation Solution

A system using LF antennas and a controller to determine the approach direction of a smart key outside the vehicle, selectively activating and deactivating touch sensors based on response signals, and switching modes to prevent malfunctions and ensure secure locking/unlocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the capacitive touch sensor is mounted in the door handle to enable passive entry, then the convenience of operation is improved, but the reliability deteriorates due to incorrect sensing of rainwater as human touch

Engineering Contradiction:

Improvepassive entry operationVSAvoidtouch sensing accuracy

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system divides the touch sensing function into multiple independent sensing zones corresponding to different door handles. Each zone has its own touch sensor that can be independently controlled, allowing the system to activate only the relevant sensor based on smart key detection direction, thereby reducing false triggers from rainwater while maintaining passive entry convenience

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary detection mechanism (smart key detection system with LF antennas) that acts as a mediator between the environment and the touch sensor. This intermediary system first detects the user's approach direction and activates the touch sensor only in the relevant door handle, preventing rainwater from triggering false touches on inactive sensors

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If the touch sensor operates continuously to detect user approach, then the responsiveness is improved, but the energy consumption increases causing battery discharge

Engineering Contradiction:

Improveresponse speedVSAvoidbattery power consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The system implements periodic action by first using the low-power LF antenna to detect smart key presence and direction, then periodically activating the touch sensor only when needed. This two-stage periodic detection approach maintains fast response capability while significantly reducing overall energy consumption compared to continuous touch sensor operation

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies preliminary action by performing smart key detection and direction determination before activating the touch sensor. This preliminary detection step ensures the touch sensor is activated only when a user is approaching, maintaining responsiveness while avoiding unnecessary energy consumption from continuous operation

Inventive Principle:

Principle #10Preliminary action

3Area of stationary object

If the touch sensor is activated in all door handles, then the coverage area is improved, but the risk of unintentional unlocking increases

Engineering Contradiction:

Improvesensor coverage areaVSAvoidunintentional unlocking risk

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The system applies local quality by making each door handle's touch sensor have different operational states based on the detected smart key approach direction. Only the door handle in the direction of the approaching user has the touch sensor activated, while other door handles remain inactive. This localized activation maintains full coverage capability when needed while minimizing the risk of unintentional unlocking on inactive doors

Inventive Principle:

Principle #3Local quality

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

Prevents sensor malfunctions, reduces battery discharge, and enhances vehicle security by accurately determining the smart key's approach direction and operating touch sensors only in the relevant door handle, thereby reducing the risk of theft.

Implementation Method 1

an LF antenna to transmit a searching signal to a smart key located outside the vehicle and receive a response signal from the smart key

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

at least one touch sensor mounted in a door of the vehicle to sense a touch input of a user in a capacitive scheme

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS12257979B2Vehicle and method for preventing malfunction of touch sensor in vehicle door

Publication Date: 2025.03.25 HYUNDAI MOTOR CO LTD

AI summary

A vehicle and a method are configured to prevent malfunction of a touch sensor in a vehicle door. The vehicle includes a transceiver for transmitting a searching signal to a smart key located outside the vehicle and receiving a response signal to the searching signal, at least one touch sensor mounted in a door of the vehicle to sense a touch input of a user in a capacitive scheme, and a controller that determines an approach direction of the smart key based on the response signal and controls to operate only a touch sensor installed in a door mapped to the approach direction among the at least one touch sensor.