Capacitive Door Handle Electrode Segmentation for False Trigger Reduction
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Solution Overview
Problem
Existing motor vehicle door handles lack efficient and reliable detection systems for user approach, leading to potential false triggering due to environmental factors like rain, and incomplete monitoring of the recessed grip area.
Innovation Solution
The use of at least two electrodes with distinct monitoring zones, including a reference electrode not accessible to the user, to enhance detection accuracy and prevent false triggering, with capacitive sensors to monitor changes in capacitance and trigger signals for the safety system, and a shielding element to protect against external influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single electrode is used for detection, then the device complexity is reduced, but the measurement precision and reliability of user approach detection deteriorates
Solution Approach 1:
The detection system is segmented into multiple electrodes (first electrode, second electrode, and reference electrode), each with distinct monitoring zones. This segmentation allows the system to cover the entire recessed grip area more comprehensively and distinguish between legitimate user approach and environmental interference by comparing signals from different zones.
Solution Approach 2:
The patent introduces a temporal dimension to the detection system by implementing sequential detection stages. The first electrode provides initial detection, followed by verification through the second electrode, and final confirmation using the reference electrode. This multi-stage temporal process enhances reliability while maintaining manageable device complexity.
2Area of stationary object
If monitoring zones overlap completely, then the coverage area is maximized, but false triggering due to environmental factors like rain increases
Solution Approach 1:
Each electrode is assigned a specific monitoring zone with distinct spatial characteristics. The first electrode monitors the approach zone, the second electrode monitors the grip zone, and the reference electrode monitors a protected zone inaccessible to users. This local differentiation allows the system to identify legitimate user interactions versus environmental factors like rain that would affect all zones uniformly.
Solution Approach 2:
The reference electrode acts as an intermediary that provides environmental baseline data. By comparing the signals from the first and second electrodes against the reference electrode's readings, the system can distinguish between capacitance changes caused by user approach and those caused by environmental factors such as rain, thereby reducing false triggering.
3Ease of operation
If the monitoring zone is made accessible to the user for interaction, then the ease of operation is improved, but the reliability of detection deteriorates due to inability to distinguish user input from environmental factors
Solution Approach 1:
The monitoring system is segmented into multiple electrodes with distinct monitoring zones. The first electrode's monitoring zone is accessible to users for normal operation, while the reference electrode's monitoring zone is positioned in a location not accessible to users. This segmentation enables the system to differentiate between legitimate user interactions and environmental factors by comparing signals from accessible and inaccessible zones.
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
This solution provides faster and more reliable detection of user approach, reducing false triggers and ensuring comprehensive monitoring of the handle's recessed grip area, even in wet conditions, thereby enhancing the security and functionality of the motor vehicle's safety system.
Implementation Method 1
at least one of the two electrodes detects a change in the capacitance
Data Source
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Figure 4
AI summary
The invention relates to a handle (10), in particular a door handle (10), for a security system (1) of a motor vehicle (2), having a handle body (12) which is shaped to form a handle recess (11), in which an electronic unit (30) is disposed which recognises the approach of a user to the handle body (12). According to the invention the electronic unit (30) has at least one first (31) and one second electrode (32, 33), each electrode (31, 32, 33) has a discrete monitoring zone (41, 42, 43) which extends into the handle recess (11), and the monitoring zone (41) of the first electrode (31) is at least partially different from the monitoring zone (32, 33) of the second electrode (32, 33).