Vehicle Pedestrian Impact Sensor Diagnostic Gas Pulse
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Solution Overview
Problem
Existing vehicle pedestrian impact sensors are prone to noise sensitivity and system time lag, making them unreliable for quick and accurate detection of pedestrian impacts, which is critical for activating safety features like hood lifting in vehicle accidents.
Innovation Solution
A vehicle impact sensor device with a tubular enclosure filled with gas and a gas pulse device that inserts or withdraws gas to create a pressure change, using a pressure sensor and control unit to determine if the input falls within an expected range, allowing for a quick and reliable diagnostic check of the sensor's functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vibration or ultrasonic waves are used to detect defects in the enclosed space, then defect detection capability is improved, but sensitivity to noise and system time lag increases
Solution Approach 1:
The system performs a preliminary diagnostic check by inserting a known volume of gas into the tubular enclosure before actual pedestrian impact detection. This preliminary action establishes a baseline pressure change response, allowing the system to verify sensor functionality and detect defects (such as leaks or sensor failures) before they affect accident detection reliability.
Solution Approach 2:
The diagnostic system creates a simulated impact scenario by injecting a controlled amount of gas into the tubular enclosure, replicating the pressure change that would occur during a real pedestrian impact. This copied scenario allows verification of sensor response without actual external interference, eliminating noise sensitivity and time lag issues present in vibration-based methods.
2Speed
If a pyrotechnical charge is used for fast-acting hood raising, then response speed is improved, but system complexity and reliability requirements increase
Solution Approach 1:
The system performs a preliminary diagnostic check by inserting a known volume of gas into the tubular enclosure before actual pedestrian impact detection. This preliminary action establishes a baseline pressure change response, allowing the system to verify sensor functionality and detect defects (such as leaks or sensor failures) before they affect accident detection reliability.
Solution Approach 2:
The control unit receives feedback from the pressure sensor regarding the baseline pressure response to gas insertion. This feedback mechanism allows the system to verify sensor functionality and adjust or flag potential defects, ensuring reliable operation of the pyrotechnical hood raising system without increasing its inherent complexity.
3Measurement precision
If the tubular enclosure is made air-tight for pressure detection, then measurement precision is improved, but defect detection becomes more critical
Solution Approach 1:
The system performs a preliminary diagnostic check by inserting a known volume of gas into the tubular enclosure before actual pedestrian impact detection. This preliminary action establishes a baseline pressure change response, allowing the system to verify sensor functionality and detect defects (such as leaks or sensor failures) before they affect accident detection reliability.
Solution Approach 2:
The control unit receives feedback from the pressure sensor regarding the baseline pressure response to gas insertion. This feedback mechanism allows the system to verify sensor functionality and adjust or flag potential defects, ensuring reliable operation of the pyrotechnical hood raising system without increasing its inherent complexity.
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 solution provides a rapid and reliable diagnostic capability for the sensor, ensuring that life-saving systems are functional and reducing the risk of false negatives or false positives in pedestrian impact detection.
Implementation Method 1
A vehicle impact sensor device with a tubular enclosure filled with gas and a gas pulse device that inserts or withdraws gas to create a pressure change
Implementation Method 2
a pressure sensor arranged to detect pressure characteristics in the the tubular enclosure
Data Source
AI summary
The present invention relates to a vehicle impact sensor device adapted to detect an impact between a vehicle (1) and a person. The sensor device (6) comprises a tubular enclosure (7) which encloses a gas-filled space (8). The tubular enclosure (7) has a first end (7a) and a second end (7b) and is arranged to extend along a bumper cover (5), when mounted to a vehicle (1). The sensor device (6) further comprises a pressure sensor (9, 9′, 11, 11′) arranged to detect pressure characteristics in the the tubular enclosure (7). The sensor device (6) also comprises a gas pulse device (11, 11′) which is connected to the tubular enclosure (7), the gas pulse device (11, 11′) being arranged to insert gas into, or withdraw gas from, the tubular enclosure (7).