Capacitive Sensor for Vehicle Door Handle Position Detection
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Solution Overview
Problem
Existing vehicle door handle systems require expensive micro switches or hall sensors to determine the position of the handle, which occupy valuable space and increase costs.
Innovation Solution
Utilizing capacitive sensors, which are already needed for hand approach detection, to also determine the position of the door handle, eliminating the need for additional micro switches or hall sensors, and incorporating a second capacitive sensor for enhanced precision and functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If micro switches or hall sensors are used to detect handle position, then position detection reliability is improved, but device complexity and cost increase
Solution Approach 1:
The capacitive sensor serves dual functions: detecting hand approach/touch for door operation and detecting handle position. By making the sensor universal, the patent eliminates the need for separate position detection sensors, thereby reducing device complexity while maintaining position detection reliability
Solution Approach 2:
The patent combines the hand detection function and position detection function into a single capacitive sensor system. The sensor and evaluation circuit evaluate different signals from the same capacitive sensor to perform both functions, merging what were previously separate detection systems
2Measurement precision
If additional position detection sensors are installed, then position information accuracy is improved, but the space required in the handle assembly increases
Solution Approach 1:
The capacitive sensor performs both hand detection and position detection functions, eliminating the need for additional dedicated position sensors. This multi-functionality approach maintains position detection precision while minimizing the space required in the handle assembly
Solution Approach 2:
By merging hand detection and position detection into a single capacitive sensor system, the patent reduces the total sensor count and the space they occupy in the handle assembly, while still achieving accurate position detection through signal evaluation
3Reliability
If micro switches are used for position detection, then position detection is achieved, but the sensor is subject to wear and has reduced lifetime
Solution Approach 1:
The patent replaces mechanical micro switches with a capacitive sensor system that detects position through electrical capacitance changes. This substitution eliminates mechanical moving parts and contact wear, thereby extending sensor lifetime while maintaining reliable position detection
Solution Approach 2:
The capacitive sensor used for position detection is a solid-state component without mechanical wear parts, making it more durable and long-lasting compared to mechanical micro switches. The sensor can operate reliably over extended periods without degradation from mechanical stress
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 results in a cost-effective, space-saving handle assembly that reliably detects the retracted, extended, and intermediate positions of the door handle, improving durability and reducing the need for redundant sensors, while potentially integrating fingerprint verification and door locking functionality.
Implementation Method 1
the sensor unit (17, 27) is arranged to evaluate a signal from the capacitive sensor (18) and to determine the position of the door handle (16) on the basis of the signal
Data Source
Figure 1~2
Figure 3~4
AI summary
A handle assembly (14) for a vehicle door (12), comprising a handle (16) which is moveable between a retracted position and an extended position, an evaluation circuit (17) and at least one capacitive sensor (18) arranged at the handle (16), the evaluation circuit (17) being adapted for detecting the presence of a hand in the vicinity of the capacitive sensor (18) and in addition being adapted for determining the position of the handle (16).