Vehicle Frame Stress Wave Airbag Detection
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Solution Overview
Problem
Existing airbag systems take too long to detect crashes, with electromechanical crash sensors requiring 10-20 ms to detect and 40-50 ms to fully deploy the airbag, necessitating a reduction in detection time for timely deployment.
Innovation Solution
The airbag system employs sensors mounted on the vehicle frame to measure stress waves propagating through the frame, with strain gauge or piezoelectric sensors positioned at predetermined intervals to sequentially detect stress waves and trigger airbag deployment when outputs exceed a threshold, reducing detection time to approximately 0.1 ms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If electromechanical crash sensors are used, then the airbag system can be easily diagnosed and manufactured at low cost, but the detection time is too long (10-20 ms)
Solution Approach 1:
The patent replaces the electromechanical sensing mechanism with a purely mechanical stress wave detection system. Strain gauges or piezoelectric sensors mounted on the vehicle frame detect stress waves directly, eliminating the need for moving masses, magnets, and mechanical circuits. This substitution reduces detection time from 10-20 ms to approximately 0.1 ms while maintaining diagnostic capability through electronic sensor outputs.
2Loss of time
If the sensing mass moves through air in the ball-in-tube sensor, then the sensor can detect crash, but air drag force dampens the sensing mass movement and increases detection time
Solution Approach 1:
The patent extracts and removes the air medium from the sensing mechanism. By mounting sensors directly on the vehicle frame, the system eliminates the tube containing air that causes drag force. The sensors detect stress waves through direct mechanical coupling to the frame, removing the damping effect entirely and enabling immediate detection without the 10-20 ms delay caused by air resistance.
3Productivity
If multiple sensors are mounted on the vehicle frame to detect stress waves, then detection time is reduced to 0.1 ms, but the device complexity increases
Solution Approach 1:
The patent segments the detection function across multiple sensor locations on the vehicle frame. By placing strain gauges or piezoelectric sensors at specific positions where stress waves propagate, the system achieves rapid 0.1 ms detection through distributed sensing. This segmentation allows parallel detection of stress waves from different impact zones, improving overall detection speed while managing complexity through strategic sensor placement.
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 significantly reduces the detection time for crashes, enabling earlier and more timely airbag deployment, enhancing passenger safety by ensuring rapid response to collision impacts.
Implementation Method 1
sensors for detecting a crash, which measures stress waves caused by an impact applied to a vehicle frame
Implementation Method 2
strain gauge or piezoelectric sensors positioned at predetermined intervals
Data Source
AI summary
The present invention may provide an airbag system for an automobile and a method of operating the same. The airbag system comprises the following: sensors mounted on a frame member of a the vehicle frame for detecting a crash by sequentially measuring stress wave cause by the crash; an electronic control unit for outputting an actuation signal based on outputs from the sensors; an inflator for generating a gas in response to the actuation signal; and an airbag operatively coupled to the inflator and being deployed by supply of the gas generated from the inflator. The sensors are mounted on the frame member at predetermined intervals in a path, along which the stress waves propagate through the frame member. The electronic control unit outputs the actuation signal when each output from each sensor exceeds a predetermined threshold. The airbag system can remarkably reduce the time required for detecting a crash by measuring the stress waves, which propagate very rapidly through the vehicle frame, thereby deploying the airbag in a timely manner.