Vehicle Rollover Detection Using Acceleration Signal Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle rollover detection systems, particularly acceleration-based approaches, struggle to accurately detect 360° rollovers and may trigger false positives, leading to unnecessary emergency calls and fuel cutoffs, which can worsen vehicle impacts and fail to correctly identify rollover positions.
Innovation Solution
A method utilizing the evaluation of characteristic signal profiles in lateral and vertical acceleration directions during a 360° rollover with ground contact to reliably detect vehicle positions, enabling the activation of secondary functions like emergency calls and fuel cutoffs, by detecting lifting-off, impact, and rest positions using sensors and an evaluation and control unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If acceleration-based approaches are used to detect stable side position or roof position after rollover, then cost-efficient detection of secondary functions is achieved, but 360° rollovers cannot be correctly detected and false positives occur in load situations
Solution Approach 1:
The detection process is segmented into multiple phases: lifting-off detection, impact detection, and rest position detection. Each phase uses specific acceleration criteria evaluated at different time points to determine rollover type, enabling accurate differentiation between 360° rollovers and stable position rollovers while maintaining cost efficiency through acceleration sensor-only architecture.
Solution Approach 2:
The system dynamically adapts its detection criteria based on the phase of the rollover event. During lifting-off, it monitors vertical acceleration; during impact, it evaluates both vertical and lateral acceleration peaks; during rest position, it checks for stable orientation. This dynamic adaptation enables accurate detection across varying rollover scenarios without requiring complex hardware.
2Reliability
If emergency call and fuel cutoff are activated upon detected rollover, then occupant safety is improved, but false positives in load situations cause unnecessary activation and more severe vehicle impact
Solution Approach 1:
The system performs preliminary detection and classification of the rollover type before activating safety functions. By first detecting lifting-off, then impact characteristics, and finally rest position or continued motion, the system determines whether a true rollover occurred before triggering emergency calls or fuel cutoff, preventing false activation during load situations.
Solution Approach 2:
The system continuously monitors acceleration signals throughout the event and uses feedback from each detection phase to adjust subsequent detection criteria. If the signal pattern indicates a load situation rather than a rollover, the system suppresses false positive activation of safety functions, thereby avoiding unnecessary fuel cutoffs that could worsen vehicle impact.
3Speed
If rotation rate sensors are used for time-critical primary functions, then activation speed is improved, but device complexity increases compared to acceleration-based approaches
Solution Approach 1:
The system uses acceleration sensors to infer rotational motion characteristics by analyzing the dynamic pattern of acceleration signals during lifting-off, impact, and rest position phases. This copying approach replicates the functionality of rotation rate sensors for secondary function detection without requiring actual gyroscopic sensors, maintaining cost efficiency while achieving sufficient detection accuracy for non-time-critical functions.
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 effectively detects 360° rollovers and minimizes false positives, allowing for robust activation of non-time-critical secondary functions, thereby reducing fire risks and ensuring accurate detection of rollover positions.
Implementation Method 1
a vertical acceleration az in a vehicle vertical direction z is detected and evaluated
Implementation Method 2
a lateral acceleration ay in a vehicle transverse direction y is detected and evaluated
Data Source
AI summary
A method, a device and a computer program for activating a secondary function of an occupant protection system, a vertical acceleration and a lateral acceleration being detected and evaluated and an instantaneous position of the vehicle being determined based on the vertical acceleration and the first lateral acceleration. In the process, a lifting-off of the vehicle and/or an impact of the vehicle on its wheels is detected. A secondary function is activated if an impact of the vehicle on its roof and/or if an impact of the vehicle on one side or an impact of the vehicle on its wheels is detected.