Vehicle Sensor Electrode and NFC Coil Layout for Low-Interference Sensing
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Solution Overview
Problem
Conventional sensor arrangements in vehicles face challenges with space constraints and interference issues in door handles, where both capacitive sensors and near-field transmission devices need to be sensitive yet compact, and must minimize interference between electronic components.
Innovation Solution
A sensor arrangement that integrates a near-field transmission coil to support capacitive detection, allowing it to perform both contactless transmission and capacitive sensing cooperatively, with the coil's winding surrounding the sensor electrode to enhance sensitivity and reduce interference, and using a printed circuit board design with specific conductor geometries to minimize eddy currents and optimize electric fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the sensor electrode and near-field transmission coil are integrated in a compact arrangement, then space requirements are reduced, but interference between the capacitive sensor and near-field transmission device increases
Solution Approach 1:
The patent combines the near-field transmission coil and capacitive sensor electrode into a single integrated sensor arrangement, where the coil surrounds the electrode. This merging allows both functions (contactless transmission and capacitive sensing) to be performed within the same spatial footprint, directly reducing the area required while managing interference through cooperative control.
Solution Approach 2:
The near-field transmission coil is designed to serve dual purposes: primarily for contactless near-field communication and secondarily to support capacitive sensing. By making the coil multi-functional, the patent eliminates the need for separate components, thereby reducing space requirements while the cooperative control mechanism manages potential interference between functions.
2Measurement precision
If the near-field transmission coil is designed to support capacitive sensing, then sensor sensitivity is improved, but the coil can only provide one function at a time
Solution Approach 1:
The patent implements dynamic functional switching where the near-field transmission coil alternates between supporting capacitive sensing and performing contactless transmission based on operational requirements. The control electronics dynamically adjust the coil's state - using it cooperatively with the sensor electrode during sensing phases, and switching to transmission mode when communication is required, thereby optimizing sensitivity when needed while maintaining overall system versatility.
Solution Approach 2:
The system employs periodic alternation between sensing mode and transmission mode. During sensing periods, the coil is configured to support capacitive detection, enhancing sensitivity. During transmission periods, it switches to near-field communication. This periodic switching allows the coil to optimize for its current function while maintaining the ability to perform both functions over time.
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 design improves the sensitivity and operation of capacitive sensors while reducing space requirements and interference, enabling reliable detection and contactless communication, facilitating features like keyless entry and authentication through a compact and cost-effective solution.
Implementation Method 1
at least one near-field transmission device, in particular a near-field transmission unit, preferably an NFC interface, wherein preferably the near-field transmission device has at least one near-field transmission coil with at least one (in particular electrically conductive) winding adjacent to the sensor electrode for contactless (in particular near-field) transmission
Implementation Method 2
The control and/or evaluation circuit measures the capacitance of the electrode relative to ground. When an operator's hand approaches the electrode, the capacitance changes, and this change in capacitance can be detected by the control and/or evaluation circuit.
Implementation Method 3
The control electronics are configured to control the near-field transmission coil cooperatively with the sensor electrode in order to support capacitive detection
Data Source
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AI summary
The invention relates to a sensor arrangement (1) for a vehicle (2), comprising: - a capacitive sensor device (10) that includes at least one sensor electrode (11) for capacitive sensing; - a near-field transmission device (20) that includes at least one near-field transmission coil (21) with at least one winding (22) adjacent to the sensor electrode (11) for contactless transmission; - control electronics (40) configured to control the near-field transmission coil (21) cooperatively to the sensor electrode (11) in order to aid with capacitive sensing.