Abstract: An improved vehicle crash sensing apparatus quickly and reliably characterizes frontal impacts with only minimal data processing requirements. Two or more longitudinally separated piezoelectric strips strategically located in a frontal portion of the vehicle produce impact signals that are analyzed to characterize the type of impact and the structural crush rate. In a simple implementation involving only two piezoelectric strips, a first strip extends laterally along a forward portion of the front bumper, and a second strip extends laterally along a forward portion of the hood panel, above and rearward of the first strip. In cases where an impact signal is developed by only one of the two strips, a high (under-ride) or low (over-ride) impact is indicated. If impact signals are developed by both strips, the intervening time is measured as an indication of the structural crush rate.

Abstract: An improved vehicle crash sensing apparatus quickly and reliably characterizes frontal impacts with only minimal data processing requirements. Two or more longitudinally separated piezoelectric strips strategically located in a frontal portion of the vehicle produce impact signals that are analyzed to characterize the type of impact and the structural crush rate. In a simple implementation involving only two piezoelectric strips, a first strip extends laterally along a forward portion of the front bumper, and a second strip extends laterally along a forward portion of the hood panel, above and rearward of the first strip. In cases where an impact signal is developed by only one of the two strips, a high (under-ride) or low (over-ride) impact is indicated. If impact signals are developed by both strips, the intervening time is measured as an indication of the structural crush rate.

Abstract: An improved weight-based occupant characterization method that can inexpensively and reliably distinguish between a child or small adult and a tightly cinched child seat. When the sensed weight is in a specified range that could be produced by a tightly cinched child seat, the system characterizes the occupant based on a detected variation in sensed weight during movement of the vehicle. If the variance of the sensed weight is below a threshold for a predetermined interval, the occupant is characterized as a child seat, since a tightly cinched seat belt severely restricts variance. If the variance exceeds the threshold for a predetermined interval, the occupant is characterized as a child or small adult. A correlative factor that can be used in distinguishing between a child seat and a child or small adult is determined by computing a slope reversal rate, or frequency, of the measured weight.