Abstract: A sensor system for detecting impacts to a vehicle, allowing for actuation decisions of passive restraint devices. The sensor system includes one or more piezoelectric sensor assemblies (42), each including a coaxial piezoelectric cable (44) contained within a tube housing (54), which is mounted to a structural member of the vehicle. The sensor system may also include accelerometers (36, 38) that are also in communication with the restraints control module (40) and employed in combination with one or more piezoelectric sensor assemblies (42). Further, the sensor system may include diagnostics for monitoring one or more of the sensor assemblies (42) in order to detect a sensor failure, while not interfering with the impact signals from the sensor assemblies (42).

Abstract: A system and method for controlling deployment of an inflatable passenger restraint utilize distance-based thresholds to improve deployment time in high-speed crash events and to improve event discrimination for side impacts. The invention uses an acceleration signal to calculate distance and to calculate average acceleration using three buffers holding differing numbers of samples. The three average accelerations are used to determine the length of the acceleration curves above and below the zero axis which is defined as positive and negative jerk. Average acceleration and jerk are compared to the distance-based thresholds to determine whether or not to deploy the inflatable restraint.