Vehicle Door Handle Capacitive Sensing With Correlated Electrodes
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Solution Overview
Problem
Existing vehicle door handle detection systems using capacitive sensors are prone to false detections due to environmental conditions such as rain or snow, which increase capacitance values and trigger unnecessary locking or unlocking.
Innovation Solution
The system employs two capacitive sensors with electrodes segmented into alternately juxtaposed segments, generating detection signals that are correlated to confirm the intention to lock or unlock, reducing false detections by ensuring simultaneous detection by both electrodes, which is less likely with rain or snow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If capacitive sensors are used to detect user approach/contact, then remote locking/unlocking functionality is enabled, but false detections occur due to environmental conditions like rain or snow
Solution Approach 1:
The electrode is divided into multiple segments (first electrode segment, second electrode segment, third electrode segment) arranged in alternating pattern. This segmentation allows the system to detect correlated signals across multiple segments, distinguishing genuine user contact from environmental interference like rain or snow that would not produce correlated detections across all segments simultaneously.
Solution Approach 2:
The system uses feedback from multiple electrode segments to verify detection validity. By requiring correlated detection signals from multiple segments before triggering locking/unlocking, the system provides feedback validation that filters out false positives from environmental conditions while maintaining reliable automated operation.
2Reliability
If multiple capacitive sensors are deployed to reduce false detections, then detection reliability improves, but device complexity increases
Solution Approach 1:
Instead of adding multiple independent sensors, the invention segments a single electrode into multiple sections that can be controlled and read independently. This achieves multi-point detection capability while avoiding the complexity of coordinating multiple separate sensor systems, as all segments share the same basic sensor infrastructure.
Solution Approach 2:
The segmented electrode structure serves multiple functions: it enables spatially distributed detection, provides correlation-based false detection filtering, and maintains compatibility with existing capacitive sensor control circuits. This multi-functionality reduces the need for additional specialized components.
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 approach significantly reduces false detections caused by rain or snow, providing a more reliable and robust method for detecting user intention to lock or unlock vehicle doors.
Implementation Method 1
the user acts as a second electrode, connected to ground, which increases the capacitance value of the detection capacitor
Data Source
AI summary
Disclosed is a device detecting intention to lock or unlock a vehicle door, including: a first capacitive sensor including a first electrode, detecting the approach and/or contact of a human body part in a predetermined region around the handle; a first sensor controller, generating a first approach and/or contact detection signal; a second capacitive sensor including a second electrode, detecting the approach of a human body part in the predetermined region, wherein: the first and second electrodes are each separate segments electrically connected to one another, the segments of the first electrode and of the second electrode are alternately juxtaposed; a second sensor controller generate a second approach and/or contact detection signal; a correlator to calculate a correlation value between the first signal and the second signal; and a confirmation unit comparing the correlation value with a predetermined value to detect intention to lock or unlock the door.