Electromechanical Foil Sensors for Vehicle Window Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sensor systems for detecting seat occupancy and preventing accidents in motor vehicles require multiple sensors, leading to complex structures and mechanical integration challenges, particularly when covering large areas like window panes.
Innovation Solution
The use of electromechanical foils made from ferroelectret materials, such as polytetrafluoroethylene and polyvinylidene fluoride, which can be easily installed on vehicle components to detect objects using ultrasound-based sensors, allowing for a common film with separate sensor electrodes and a protective layer for damage prevention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple sensors are used to detect seat occupancy and prevent accidents, then detection reliability is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple sensor functions into a single electromechanical foil with multiple sensor electrodes. The foil integrates the sensing element, electrode structure, and protective layer into one component, eliminating the need for separate sensors while maintaining reliable detection of seat occupancy and foreign objects
Solution Approach 2:
The electromechanical foil serves multiple functions simultaneously: it acts as both the sensing element for detecting objects and as the electrode structure for generating ultrasound. This multi-functionality reduces the number of components needed while improving detection reliability across different measurement points
2Measurement precision
If multiple sensors are arranged to cover large areas like window panes, then measurement precision is improved, but ease of manufacture deteriorates
Solution Approach 1:
The electromechanical foil is divided into multiple sensor electrodes (first, second, third sensor electrodes) that can be independently positioned to cover different areas. Each electrode acts as an independent sensing point, providing precise measurement coverage across large surfaces like window panes while remaining part of a single manufacturable component
Solution Approach 2:
Multiple sensor electrodes are integrated into a single electromechanical foil structure, combining what would traditionally require multiple separate sensors into one manufacturable unit. This segmentation of sensing points within a unified structure improves measurement precision while maintaining ease of manufacture
3Measurement precision
If sensors are positioned within the frame to cover the entire opening area, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The sensing area is segmented into multiple discrete sensor electrodes positioned at different locations within the frame. This segmentation allows precise coverage of the entire opening area while keeping each electrode as a simple, easily integrated element of the electromechanical foil
Solution Approach 2:
The electromechanical foil with multiple sensor electrodes serves as both the structural element and the sensing element. This multi-functionality eliminates the need for separate sensor mounting structures, reducing device complexity while maintaining precise measurement coverage
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 simplifies sensor installation, reduces complexity, and enables effective detection of seat occupancy and foreign bodies near closing windows, preventing accidents by generating vibration and voltage signals for distance and position determination.
Implementation Method 1
at least two ultrasound-based sensors, with the ultrasound-based sensors being able to determine the distance between an object and the sensor
Implementation Method 2
each ultrasound-based sensor comprises an electromechanical foil, the electromechanical foil comprising a membrane made of a ferroelectret material consisting of closed-pore polymer foams
Data Source
Figure 1~1.1
Figure 2
AI summary
The invention relates to a device for detecting at least one body part of a person in a defined location, comprising at least two ultrasound-based sensors, the distance of an object to the sensor being determinable by means of the ultrasound-based sensors and the distances determined by the sensors being usable to determine the position of the object, or at least one pressure-sensitive sensor which detects the pressure exerted by a body part. Each ultrasound-based sensor or pressure-sensitive sensor comprises an electromechanical film, a grounded electrode being applied to one side of the electromechanical film and a sensor electrode being applied to the side of the electromechanical film opposite the grounded electrode.