Capacitive Approach Sensor Sealing for Environmental Protection
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Solution Overview
Problem
Capacitive approach sensors in vehicles are sensitive to environmental conditions such as humidity and condensation, leading to reduced detection sensitivity and increased manufacturing costs due to the need for specialized components for each application.
Innovation Solution
A modular approach detection device with a capacitive sensor system exposed to the environment, protected by a compressible sealing means with through holes to minimize expansion pressure and maintain detection sensitivity, allowing for universal application and cost-effective manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the capacitive sensor assembly is disposed behind a housing wall with insulating material filling the space, then protection against environmental influences is improved, but detection sensitivity deteriorates due to the dielectric medium affecting capacity
Solution Approach 1:
The invention extracts the insulating material from the detection region by creating a detection opening in the housing wall. The capacitive sensor assembly remains protected behind the housing wall, but the active sensing area is exposed through the opening, allowing direct contact with the environment and eliminating the dielectric interference that would otherwise reduce detection sensitivity.
Solution Approach 2:
The housing structure is designed with different properties in different regions: the housing wall provides general protection and insulation, while the detection opening creates a localized region without insulating material. This allows the sensor to have protected surroundings while maintaining an exposed, sensitive detection area free from dielectric interference.
2Reliability
If specialized components are manufactured for each sensor device, then protection against environmental influences is improved, but manufacturing costs increase
Solution Approach 1:
The invention creates a universal housing structure with a standardized detection opening and sensor carrier assembly that can be used across different sensor devices. The modular design allows the same protected housing configuration to accommodate various capacitive sensor assemblies, eliminating the need to manufacture specialized protective components for each specific sensor device while maintaining environmental protection.
3Strength
If the active capacitive surface is covered by the carrier frame, then structural protection is improved, but detection sensitivity deteriorates due to impact on capacity
Solution Approach 1:
The carrier frame is segmented to include a detection opening that exposes the active capacitive surface. Rather than completely covering the sensor, the frame structure is divided into regions: protected areas providing structural support and an exposed detection region allowing direct environmental contact. This segmentation maintains structural integrity while preserving sensor sensitivity.
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 provides optimal protection against environmental influences while maintaining detection sensitivity and reducing manufacturing costs by using a modular design with a sealing means that minimizes interference with the capacitive sensor's performance.
Implementation Method 1
the change in the capacity of an electrode assembly is measured, wherein the capacity is a function of the distance of a body part of the user to the electrode assembly
Implementation Method 2
a sealing means (11), which is disposed in the receiving space on the sensor carrier at least in the region of the active capacitive surface of the capacitive approach sensor
Data Source
AI summary
An approach detection device for motor vehicles includes a sensor carrier and a sensor electronic system disposed in a receiving space therein. The device includes a capacitive approach sensor coupled to an evaluation circuit which has a capacitive surface for detecting approaches. The device is mounted via a carrier frame, including a fastening section, to a vehicle body part and includes a detection opening. The sensor carrier is fastened to the carrier frame such that the active capacitive surface of the sensor is oriented toward the detection opening. A receiving space is defined by the detection opening and the sensor carrier and is formed in the region of the detection opening. A sealing element is disposed in the receiving space on the sensor carrier.