Vehicle Safety Triggering with Redundant Accelerometer Backup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing arrangements for triggering vehicle safety devices, such as airbags, may inadvertently fail to activate due to the reliance on proximity sensors, which can fail to detect objects, leading to incomplete triggering signals.
Innovation Solution
An arrangement incorporating a main accelerometer and a supplementary accelerometer, along with processing units to perform crash and arming algorithms, ensures the generation of a triggering signal even if the proximity sensor fails, by utilizing signals from both accelerometers to generate a backup triggering signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a proximity sensor is used to provide output related to distance or relative speed for crash discrimination, then the ability to discriminate between dangerous and non-dangerous crashes is improved, but the reliability of triggering the safety device deteriorates when the proximity sensor fails to detect an object
Solution Approach 1:
The patent implements a backup mechanism using accelerometers that is activated beforehand to compensate for potential proximity sensor failures. The system is designed with redundant sensing capabilities where accelerometer-based crash detection serves as a pre-prepared backup that can take over if the proximity sensor fails, ensuring continuous reliable operation without requiring real-time intervention.
Solution Approach 2:
The patent changes the detection parameters by switching from proximity sensor measurements (distance, relative speed) to accelerometer measurements (acceleration, impact force) when the proximity sensor is unavailable. This parameter substitution allows the system to maintain crash detection functionality using different physical quantities that can be measured reliably even when optical or radar-based proximity sensing fails.
2Reliability
If two processing arrangements with separate algorithms are used, then the risk of single error causing inadvertent triggering is reduced, but the device complexity increases
Solution Approach 1:
The patent merges the functionality of multiple processing arrangements into a single integrated processing unit that executes different algorithms based on sensor availability. Instead of requiring physically separate processing units for proximity-based crash detection and accelerometer-based backup detection, the system combines these functions in one processor that dynamically selects which algorithm to execute, thereby reducing hardware complexity while maintaining the reliability benefits of multiple detection pathways.
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 ensures reliable activation of vehicle safety devices by providing a backup mechanism that uses accelerometer signals to generate a triggering signal, minimizing the risk of inadvertent failure due to proximity sensor malfunctions.
Implementation Method 1
a main accelerometer sensitive to acceleration in a predetermined direction
Implementation Method 2
a supplementary accelerometer
Implementation Method 3
a proximity sensor such as a radar configured to provide an output related to the distance to an object and/or the relative speed between the object and the sensor
Data Source
AI summary
An arrangement is provided for triggering a vehicle safety device. A proximity sensor (1) provides an output related to a distance to an object and/or the relative speed between the object and the sensor. A main accelerometer (2) is sensitive to acceleration in a predetermined direction. A supplementary accelerometer (3) is also provided. A first processing arrangement (4) performs an algorithm with the main algorithm, and is connected to receive an input from the proximity sensor and from the main accelerometer and to provide an output to a triggering signal generator (5). There is a second processing arrangement (7) which receives a signal from the main accelerometer (2) and also from the supplementary accelerometer (3). The second processing arrangement also provides an output connected to the said signal generator (5) to generate the triggering signal.