Abstract: A satellite crash sensor for use in a noisy area such as a crush zone has a crash dependent clock that uses an accumulated velocity signal derived from the acceleration signal, rather than the acceleration signal itself, to determine initiation and counting of the clock count. Successive velocity values are accumulated in an accumulated velocity value that is limited between zero and a maximum limit value. The clock count is incremented away from an initial zero value when the accumulated velocity value is greater than zero and back toward the zero value when the accumulated velocity value is equal to zero. The clock count is used as a measure of time from initiation of a possible crash event in the generation of a restraint deploy indicating signal in the satellite crash sensor.

Abstract: A vehicle satellite crash sensor includes a microcomputer with a stored datum indicating intended use in a frontal application such as the front crush space or a side application such as a vehicle side door. The microcomputer also stores a program that processes a sensed acceleration signal, derives an oscillation value and derives an occupant restraint deployment signal at least in response to the oscillation value. The program includes stored code for two alternative oscillation derivation algorithms: one of which is used in frontal applications and derives an integral of the absolute value of the sensed acceleration signal; the other of which is used in side applications and derives an integral of the sensed acceleration. The stored datum determines which of the stored oscillation algorithms is used.

Abstract: A satellite crash sensor for a motor vehicle occupant restraint system that provides multi-stage deploy signaling in a manner that detects a second stage deploy crash event having an initial velocity rise followed by a loss of velocity that delays the continuation of the velocity rise. The sensor derives a velocity value from an accelerometer signal. The initiation of a possible crash event is detected and a clock count indicating a time progression into the event is initiated. A constant second stage threshold value and data defining a first stage threshold varying as function of the clock count are stored. Only for a time indicated by a first predetermined value of the clock count, a second stage datum is stored if the velocity exceeds the second stage threshold value.

Abstract: The airbag system includes in addition to conventional crash sensing apparatus seat sensors to gauge occupant mass, an occupant position sensor and a vehicle speed sensor. Desired initial restraining force is calculated from speed at impact and the occupant's mass, and an appropriate degree of inflation is effected. The occupant speed is continuously calculated from the position sensor signal and the vehicle speed. A target speed profile is established based on an estimated restraint period and the vehicle speed, and an airbag vent is varied to control the occupant speed to the target speed. The target speed profile is adjusted as a function of passenger compartment acceleration to account for vehicle speed variations and for vehicle crush.