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Pressure Based Sensing Approach for Front Impacts
Abstract:
This study demonstrates the use of pressure sensing technology to predict the crash severity of frontal impacts. It presents an investigation of the pressure change in the front structural elements (bumper, crush cans, rails) during crash events. A series of subsystem tests were conducted in the laboratory that represent a typical frontal crash development series and provided empirical data to support the analysis of the concept.
The pressure signal energy at different sensor mounting locations was studied and design concepts were developed for amplifying the pressure signal. In addition, a pressure signal processing methodology was developed that relies on the analysis of the air flow behavior by normalizing and integrating the pressure changes. The processed signal from the pressure sensor is combined with the restraint control module (RCM) signals to define the crash severity, discriminate between the frontal crash modes and deploy the required restraint devices.
A parametric analysis was conducted to study the sensitivity of the factors that might affect the pressure signal. The results demonstrate that the material, thickness, geometry, openings and energy absorbing material are parameters that should be analyzed and optimized.
Improved pressure signals were demonstrated by new system design concepts. The concept of these designs relies on the fluid analysis of air flow in converged, diverged and converged-diverged control volumes and its interface with the dynamic deformation of the surrounding structure. The initial subsystem test data for these designs showed potential for improvement in the signals and the overall system performance.
This study demonstrates that front pressure sensing concepts have the potential to improve overall system performance. However, more analysis on vehicle level crash testing is needed and algorithms that utilize such concepts are required.