Capacitive Area Sensor for Vehicle Collision Detection
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Solution Overview
Problem
Current collision detection systems in motor vehicles rely on small, localized sensors that struggle to accurately determine the relative collision speed and overlap with collision partners due to their limited operational area, leading to challenges in recognizing the impacted side during collisions, especially with varying collision partners and short decision times.
Innovation Solution
A capacitive area-sensor is integrated onto a metal component, such as a bumper, extending over at least half its width, which changes capacitance upon collision, allowing for more accurate data acquisition and control of restraint systems by providing a larger detection surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If small localized sensors are used for collision detection, then the device complexity is reduced, but the measurement precision of collision information deteriorates
Solution Approach 1:
The patent combines multiple small sensor functions into a single capacitive area sensor that covers a large surface area. This merging approach maintains low device complexity while achieving high measurement precision by detecting collision forces across the entire bumper surface through capacitance changes.
Solution Approach 2:
The capacitive area sensor serves multiple functions simultaneously: it detects collision presence, determines collision position, measures collision force intensity, and provides temporal collision data. This multi-functionality eliminates the need for multiple specialized sensors, resolving the contradiction between device complexity and measurement precision.
2Area of stationary object
If multiple sensors with narrow perimeters of operation are distributed over the vehicle front, then the detection coverage is improved, but the device complexity increases
Solution Approach 1:
The patent merges the functionality of multiple distributed sensors into a single capacitive area sensor that inherently provides full detection coverage across the bumper surface. This eliminates the complexity of distributing multiple sensors while maintaining comprehensive detection capability through the sensor's large active area.
3Ease of manufacture
If small sensors are used for collision detection, then the manufacturing cost is reduced, but the reliability of collision information determination deteriorates
Solution Approach 1:
The capacitive area sensor provides reliable collision severity assessment through its ability to detect force distribution, collision position, and impact intensity simultaneously. This single sensor replaces multiple sensors, maintaining ease of manufacture while significantly improving reliability of collision information determination.
4Measurement precision
If a large area sensor is used to improve detection accuracy, then the measurement precision of collision information is improved, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical sensor arrays with a capacitive sensing system that uses electrical field detection. This substitution achieves high measurement precision for collision data while reducing device complexity, as the capacitive sensor can be implemented as a simple conductive layer without mechanical moving parts or complex structural elements.
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
The capacitive area-sensor enables precise detection of collision information like relative speed and overlap, improving the actuation of restraint means by offering a larger data acquisition plane and immediate signal generation at the point of collision, enhancing collision detection accuracy.
Implementation Method 1
at least one sensor unit (2) including a capacitively operating sensor (2) and an associated control device (10) for collision detection
Implementation Method 2
the capacitance of the sensor (2) changes as a result of a collision-related deformation of the sensor (2)
Data Source
AI summary
A motor vehicle includes a fender provided at the front and the rear and at least one sensor device including a capacitively operating sensor and an associated control device for collision detection, wherein the sensor is arranged on a fender and is formed as a surface sensor which extends over at least half the width of the fender, wherein the control device is able to determine information resulting from a collision with an object by using the capacitance of the sensor, which changes as a result of collision-induced deformation of the sensor.