Adaptive Pedestrian Protection Triggering via Dual-Sensor Thresholds
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Solution Overview
Problem
Existing pedestrian protection systems in vehicles face challenges in accurately triggering protection mechanisms due to variations in mass and speed of collision objects, leading to potential accidental deployments or missed activations.
Innovation Solution
A method that adapts threshold values by comparing signal features from both pressure and acceleration sensors, ensuring improved triggering of pedestrian protection systems through adaptive threshold comparisons and plausibility checks using multiple sensors, including pressure tube sensors and pedestrian collision sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single sensor system (pressure or acceleration) is used for detecting pedestrian collisions, then the device complexity is reduced, but the measurement precision and reliability deteriorate due to variations in mass and speed of collision objects
Solution Approach 1:
The patent combines pressure tube sensors and acceleration sensors into a hybrid sensor system. The pressure tube sensor detects collision force through pressure changes in a fluid-filled tube, while the acceleration sensor measures deceleration of the vehicle bumper. By merging these two different sensing mechanisms, the system achieves more precise and reliable pedestrian collision detection compared to using either sensor type alone.
2Ease of operation
If fixed threshold values are used for triggering pedestrian protection means, then the ease of operation is improved, but the adaptability deteriorates due to variations in collision object mass and speed
Solution Approach 1:
The patent implements dynamic threshold adaptation where the triggering threshold is not fixed but adapts based on the specific collision scenario. The system evaluates signals from both pressure and acceleration sensors, and the threshold for triggering pedestrian protection means is adjusted dynamically according to the detected collision characteristics, enabling appropriate response to different collision objects (pedestrians, cyclists, animals) with varying mass and speed.
Solution Approach 2:
The system changes the threshold parameter dynamically based on collision detection results. Instead of using a single fixed threshold value, the triggering threshold is modified according to the combined signal evaluation from multiple sensors, allowing the system to adapt its sensitivity and triggering behavior to different collision scenarios while maintaining operational simplicity.
3Device complexity
If signal evaluation is based on a single sensor type, then the device complexity is reduced, but the reliability deteriorates in cases of sensor failure or inaccurate detection
Solution Approach 1:
The patent applies different evaluation criteria and threshold values to signals from different sensor types. The pressure tube sensor signals are evaluated based on pressure change characteristics, while acceleration sensor signals are evaluated based on deceleration patterns. Each sensor type has its own optimized evaluation method tailored to its specific measurement characteristics, improving overall detection reliability while managing complexity through specialized local processing.
Solution Approach 2:
The system uses feedback from multiple sensor channels to verify and cross-validate collision detections. When a collision is detected by one sensor type, the system checks for consistent signals from the other sensor type, providing a feedback mechanism that enhances reliability and reduces false positives while maintaining manageable system complexity through coordinated signal evaluation.
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 enhances the reliability and accuracy of triggering pedestrian protection systems, minimizing accidental deployments and improving the recognition of collision objects, even in cases of sensor failure, by integrating signals from multiple sensors for enhanced classification and plausibility verification.
Implementation Method 1
the pressure sensors are able to detect an impact of an object on the bumper via a change in pressure in the silicone tube
Implementation Method 2
Systems based on two or more acceleration sensors are widely used. Corresponding sensors for detecting a collision of a pedestrian with a vehicle are referred to as pedestrian collision sensors (PCSs)
Data Source
AI summary
A method is provided for activating a pedestrian protection system of a vehicle. The method includes a step of carrying out a first threshold value comparison, in the first threshold value comparison at least one signal feature of a first sensor signal being compared to an adaptation threshold value, a step of determining a threshold value adaptation value based on a result of the first threshold value comparison, and a step of carrying out a second threshold value comparison. In the second threshold value comparison, at least one signal feature of a second sensor signal is compared to a triggering threshold value, which is adapted using the threshold value adaptation value, for triggering the pedestrian protection system.