Vehicle Door Touch Sensor Control for Rainwater False Triggers
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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 direction sensing of the smart key approach.
Innovation Solution
A vehicle system using a transceiver to transmit and receive signals from a smart key outside the vehicle, determining the approach direction of the key using LF antennas and a controller to operate only the relevant touch sensor, switching it between sleep and wake-up modes based on the key's location and user input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a 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
Solution Approach 1:
The system segments the touch sensing function by direction, dividing the door handle surface into multiple sensing zones (front surface, side surface, rear surface) corresponding to different approach directions. Only the touch sensor in the zone matching the smart key approach direction is activated, preventing rainwater on other surfaces from causing false triggers.
Solution Approach 2:
The system dynamically activates or deactivates touch sensors based on the real-time approach direction of the smart key. The controller determines which door the user is approaching and selectively enables only the relevant touch sensor, making the sensing system adaptive to environmental conditions and user intent.
2Speed
If the touch sensor operates continuously to detect user touch, then the responsiveness is improved, but the energy consumption increases causing battery discharge
Solution Approach 1:
Instead of continuous operation, the touch sensor operates periodically based on detected events. The system first uses the low-power LF antenna to detect smart key approach, then activates the touch sensor only when needed. This periodic activation based on external triggers significantly reduces energy consumption while maintaining responsive operation when required.
Solution Approach 2:
The system performs preliminary detection using the LF antenna to determine smart key approach direction before activating the touch sensor. This preliminary action ensures the touch sensor is only activated when a legitimate user is approaching, preventing unnecessary energy consumption while ensuring rapid response when needed.
3Adaptability or versatility
If the touch sensor is activated in all doors to ensure comprehensive coverage, then the adaptability is improved, but the loss of energy increases due to unnecessary operation in irrelevant directions
Solution Approach 1:
The system applies local quality by enabling touch sensing functionality only in the specific door zone where the user is approaching. Different doors have different touch sensor activation states based on the smart key approach direction, ensuring energy is spent only where needed while maintaining comprehensive coverage capability across all doors.
4Measurement precision
If the capacitive touch sensor senses any conductive material, then the sensitivity is improved, but the reliability deteriorates due to false detection of rainwater as human touch
Solution Approach 1:
The touch sensing function is segmented by spatial location and approach direction. The door handle surface is divided into multiple zones, and only the zone corresponding to the smart key approach direction is activated. This segmentation maintains high sensitivity within the active zone while preventing false detection from rainwater or other conductive materials on inactive zones.
Solution Approach 2:
The system uses feedback from the LF antenna detection to control touch sensor activation. The LF antenna continuously monitors for smart key presence and provides feedback to the controller, which then activates or deactivates the touch sensor accordingly. This feedback mechanism ensures the high-sensitivity touch sensor operates only when a legitimate user is present, eliminating false triggers from environmental factors.
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 malfunction of touch sensors by accurately determining the smart key's approach direction, reducing battery discharge and vehicle theft risks, while ensuring secure operation of the vehicle doors.
Implementation Method 1
a transceiver for transmitting a searching signal to a smart key located outside the vehicle and receiving a response signal from the smart key
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
Data Source
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.