Capacitive Door-Opening Sensor Electrode With Alternating Sensitivity Zones
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Solution Overview
Problem
Existing capacitive sensor arrangements for motor vehicles are prone to false detections and are space-consuming and expensive, leading to undesired switching or actuation processes.
Innovation Solution
A capacitive sensor arrangement featuring elongated flat electrodes with alternating sections of different surface widths, providing varying sensitivity and flexibility, coupled with a deformable insulative covering to enhance detection accuracy and adaptability to vehicle contours.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a uniform wide sensor electrode is used to ensure sufficient detection sensitivity, then the sensitivity is improved, but the device becomes less flexible and more space-consuming
Solution Approach 1:
The sensor electrode is divided into alternating sections of different widths along its longitudinal axis, creating a segmented structure with varying sensitivity zones that maintains overall flexibility while providing sufficient detection capability in critical areas
Solution Approach 2:
Different sections of the electrode are designed with different widths to create locally optimized sensitivity characteristics, where wider sections provide higher sensitivity and narrower sections maintain flexibility and reduce space requirements
2Measurement precision
If a uniform wide sensor electrode is used to ensure sufficient detection sensitivity, then the sensitivity is improved, but the device complexity and cost increase
Solution Approach 1:
The electrode is segmented into alternating wide and narrow sections, providing sufficient detection sensitivity in wide sections while keeping the overall device simple and cost-effective through the regular alternating pattern
Solution Approach 2:
The electrode width parameter is varied periodically along the longitudinal axis, creating alternating sensitivity zones that maintain detection performance while simplifying the overall device design compared to uniformly wide electrodes
3Adaptability or versatility
If the sensor electrode is made flexible to adapt to vehicle contours, then the adaptability is improved, but the manufacturing precision becomes more difficult to maintain
Solution Approach 1:
The electrode is designed as a continuous flexible strip with periodically varying width, where the segmented alternating pattern of wide and narrow sections maintains manufacturing precision through regular geometric repetition while enabling flexibility for contour adaptation
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 improves sensitivity and flexibility, reducing false detections and allowing for reliable actuation requests while being space-efficient and adaptable to different vehicle shapes.
Implementation Method 1
A capacitive sensor arrangement with a sensor electrode, with a ground background electrode arranged at a distance behind the sensor electrode, and with a shielding electrode, which is arranged between the sensor electrode and the ground background electrode
Implementation Method 2
The provision of a shielding electrode between the sensor electrode and the background electrode, which is at ground potential, as is known from these publications, has the advantage that the sensitivity of the capacitive sensor formed in this way to changes in the space in front of the sensor electrode
Data Source
Figure 1~2
Figure 3a~3c
AI summary
The invention relates to a sensor arrangement for sensing movement gestures close to a motor vehicle, comprising a capacitive sensor electrode (2; 12) and at least one control and evaluation device (4) which is coupled to the sensor electrode and which senses a change in the capacitance of the sensor electrode. The sensor electrode (2; 12) is embodied as an elongate flat electrode, whereby in the longitudinal direction, sensitive electrode sections (a) having a first surface width alternate with less sensitive sections (b) having a second, narrower surface width such that electrode surfaces, which have different levels of sensitivity, different measurements and which are continuously conductive in sections, are formed.