Tubular Capacitive Sensor Electrode for Compact Vehicle Actuation
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Solution Overview
Problem
Existing capacitive sensors in vehicles are limited by their flat design, which restricts their functionality and detection area, particularly in compact spaces, and are prone to false triggers from non-user objects.
Innovation Solution
A tubular capacitive sensor electrode is designed with a flange section and a hollow cylindrical shape, allowing for a compact construction and enhanced detection area, coupled with a lighting unit and switch mechanism to ensure user activation and prevent false triggers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If a flat sensor electrode is used, then the device can be installed in components with limited space, but the detection area and mechanical functionality are restricted
Solution Approach 1:
The sensor electrode is transformed from a flat two-dimensional structure to a tubular three-dimensional structure. This dimensional change allows the electric field to extend along the axial direction of the tube, significantly increasing the detection area while maintaining compact installation space. The tubular geometry enables the sensor to detect objects from multiple spatial positions simultaneously.
Solution Approach 2:
The sensor electrode adopts a curved tubular geometry instead of a flat planar shape. This curvature allows the electric field to distribute more effectively in three-dimensional space, enhancing the detection area. The rounded tubular form also provides mechanical functionality that can be actuated by user interaction, combining sensing and actuation capabilities in one structure.
2Measurement precision
If the sensor electrode is positioned deeper within the actuating device, then installation space is optimized, but the electric field is farther from the user-accessible surface, reducing detection sensitivity
Solution Approach 1:
By transforming the electrode into a tubular structure, the electric field is extended along the axial dimension of the tube. This allows the field to reach closer to the outer surface of the actuating device while maintaining a compact overall structure. The tubular geometry effectively projects the sensing field outward, improving detection sensitivity without increasing the device's footprint.
3Area of moving object
If the detection area is increased, then user interaction is enhanced, but the device becomes more prone to false triggers from non-user objects
Solution Approach 1:
The tubular sensor electrode creates a concentrated electric field distribution along its axial length, with the field strength being highest near the outer surface where user interaction occurs. This localized field concentration allows for enhanced user detection while maintaining discrimination against distant objects. The flange section further concentrates the field at specific interaction points.
4Area of moving object
If a flange section is added to the tubular body, then the detection area is increased, but the device complexity increases
Solution Approach 1:
The flange section is integrated as an extension of the tubular body, forming a unified sensor electrode structure. This merging of the flange with the tubular geometry creates additional detection surface area without requiring separate components or complex assembly. The flange and tube together form a continuous conductive structure that simplifies manufacturing while enhancing detection capability.
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 tubular design increases the detection area and mechanical functionality, reduces false triggers, and allows for compact installation in vehicle surfaces, enhancing user interaction and safety.
Implementation Method 1
The capacitive sensor can comprise a sensor electrode and a control unit... The control unit measures and evaluates the capacitance of the electrode relative to a ground. When a user's hand approaches, the electric field in front of the flat sensor electrode changes, thus altering the electrode's capacitance
Implementation Method 2
When a user's hand approaches, the electric field in front of the flat sensor electrode changes, thus altering the electrode's capacitance, which can be detected by the control unit
Data Source
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AI summary
Actuating device (2) for triggering a function of a vehicle by a user comprising an operating area (4) for detecting a manual actuation by the user to trigger a function of the vehicle and a capacitive sensor (6) for detecting an approach and/or a touch by a user, wherein the sensor (6) comprises an electrically conductive sensor electrode (6), wherein the sensor electrode (6) is designed as a tubular body, in particular in the form of a hollow cylindrical body.