Vehicle Input Device Capacitive Sensor Noise Filtering
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Solution Overview
Problem
Capacitive proximity sensors in vehicles face poor sensitivity due to surrounding noise, leading to incorrect activation from objects like smartphones or console devices within the detection area.
Innovation Solution
The input device employs a design with first and second sensor electrodes arranged at different densities in specific channel areas, where the controller determines a capacitive reference value by filtering out noise from sensor values, deactivating electrodes outputting beyond a predetermined range and reactivating them when within range, to improve sensitivity and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a capacitive proximity sensor is used to detect objects in the vehicle, then the detection function is provided, but the sensor experiences poor sensitivity due to surrounding noise from objects like smartphones or console devices
Solution Approach 1:
The sensor electrodes are divided into multiple channels with different densities. High-density channels are placed in noise-prone areas to detect and filter noise, while low-density channels are placed in areas requiring accurate detection. This segmentation allows the system to differentiate between noise sources and actual detection targets by comparing signals across different channel densities.
Solution Approach 2:
Different channel densities are assigned to different spatial locations based on their noise characteristics. Areas with high noise interference (e.g., near console or smartphone placement zones) receive high-density sensor electrode channels, while areas requiring precise detection receive low-density channels. This local differentiation optimizes the balance between noise filtering and detection accuracy across the sensor surface.
2Measurement precision
If sensor electrodes are arranged with high density to improve detection accuracy, then measurement precision improves, but the device complexity and noise sensitivity increase
Solution Approach 1:
Instead of uniformly high density across all channels, the patent applies different density levels to different spatial locations based on their specific detection requirements and noise environments. This localized approach maintains high detection accuracy where needed while reducing overall device complexity and noise susceptibility.
Solution Approach 2:
The sensor array is segmented into multiple channels with varying densities rather than using a single high-density configuration. This segmentation reduces the total number of channels required while maintaining detection accuracy in critical areas, thereby reducing device complexity and processing requirements.
3Measurement precision
If the capacitive reference value is calculated using all sensor electrodes, then the calculation is comprehensive, but noise from inactive electrodes degrades the reference value accuracy
Solution Approach 1:
The controller extracts and identifies noise-containing sensor values from individual channels by analyzing their output characteristics. Channels exhibiting noise patterns (such as consistently high or unstable readings) are identified and excluded from the capacitive reference value calculation. This extraction of harmful elements ensures that the reference value is derived only from clean, reliable sensor data.
Solution Approach 2:
The system continuously monitors sensor electrode outputs and provides feedback to the controller about which channels are producing noise. Based on this feedback, the controller dynamically adjusts which channels contribute to the reference value calculation, ensuring optimal accuracy by excluding noisy channels while maintaining comprehensive use of valid sensor data.
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 enhances detection sensitivity by minimizing noise interference and preventing incorrect recognition, thereby improving the precision of capacitive reference value calculations in noisy environments.
Implementation Method 1
A capacitive proximity sensor technology relates to detecting a change in capacitance of a proximity sensor by an approaching object and determining whether the object is approaching by comparing the detected capacitance and a reference value.
Data Source
AI summary
The present disclosure relates to an input device for vehicle and control method of the same, and more particularly, to an input device for vehicle implemented as a plurality of sensor electrodes and control method of the input device. The input device may include: first sensor electrodes arranged in a first preset channel area with a first preset density; second sensor electrodes arranged in a second preset channel area with a second preset density, the second density being less than the first density; and a controller configured to determine a capacitive reference value of the input device based on first sensor value information that is collected from the first sensor electrodes and the second sensor electrodes.