Variable Impedance Touch Array for Precise Automotive Force Sensing
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Solution Overview
Problem
Current automotive touch sensor systems lack efficient methods to accurately detect proximity, contact, and pressure with spatial location, limiting their effectiveness in gesture recognition and control applications.
Innovation Solution
The implementation of an interpolated variable impedance touch sensor array, which includes interlinked impedance columns and rows, uses a column switching register and row switching register to drive and sense currents, allowing for accurate detection of touch proximity and pressure through interpolation of sensed current/voltage, and is integrated into steering wheels, seat belts, and accelerator pedals to control various automotive functions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional touch sensor systems are used, then the system structure is simple, but the detection precision of touch location, proximity, and pressure is insufficient
Solution Approach 1:
The touch sensor system is divided into multiple independent sensing elements arranged in a grid pattern, with each element capable of independent detection. This segmentation allows precise localization of touch events by identifying which specific grid element is activated, thereby improving detection precision while maintaining manageable system complexity through modular architecture
Solution Approach 2:
The patent transitions from traditional single-point or simple area touch detection to a two-dimensional grid array system. By adding the spatial dimension of multiple sensing elements arranged in rows and columns, the system achieves precise touch location detection across the surface, transforming simple touch presence detection into detailed spatial and pressure measurement
2Measurement precision
If more sensing elements are added to improve detection accuracy, then the measurement precision improves, but the device complexity and cost increase
Solution Approach 1:
The sensing array is segmented into discrete grid elements with standardized structures, allowing the system to achieve high spatial resolution through replication of simple, identical sensing units rather than using complex individual sensors for each position
Solution Approach 2:
Each sensing element in the grid array serves multiple functions: detecting touch presence, determining spatial location, and measuring pressure magnitude. This multi-functionality of identical sensing elements across the array reduces overall system complexity compared to using different specialized sensors for each function
3Adaptability or versatility
If variable impedance array is implemented, then the detection capability for pressure and contact is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The system utilizes variable impedance characteristics of the sensing elements to detect different touch conditions (proximity, contact, pressure). By measuring changes in electrical impedance parameters rather than requiring precise mechanical or optical measurements, the system achieves enhanced detection capability while reducing manufacturing precision requirements
Solution Approach 2:
The patent replaces traditional mechanical or optical touch sensing mechanisms with electrical impedance-based detection. This substitution eliminates the need for precise mechanical tolerances and optical alignment, thereby reducing manufacturing precision requirements while improving detection versatility for various touch types
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 enables precise detection of touch location, force, and patterns, allowing for intuitive control of vehicle functions like headlights, wipers, and audio systems, while also monitoring driver grip and seat belt fit, enhancing safety and user interaction.
Implementation Method 1
a variable impedance array electrically coupling interlinked impedance columns coupled to an array column driver and interlinked impedance rows coupled to an array row sensor
Implementation Method 2
The array column driver is configured to select the interlinked impedance columns based on a column switching register and electrically drive the interlinked impedance columns using a column driving source
Implementation Method 3
The array row sensor selects the interlinked impedance rows within the touch sensor array and electrically senses the interlinked impedance rows state based on a row switching register
Data Source
AI summary
The present invention relates to automotive interface systems and methods. In one embodiment, an automotive interface system includes a steering wheel and an integrated interpolated variable impedance array that comprises a grid of sensing elements. The sensing elements are configured to power on simultaneously and to simultaneously generate multiple currents along multiple current paths in response to sensing a touch wherein the amount of current generated by a sensing element of the grid is directly proportional to the force applied by the touch. The automotive interface system also includes an analog-to-digital converter (ADC) and a processor communicatively coupled to the interpolated variable impedance array that are configured to receive the multiple currents along multiple current paths and determine a location, a duration, an area, and a force of the touch from the multiple currents along multiple current paths.