摘要:
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. For a longer time determined by a second predetermined clock count, the velocity value is compared with a clock count determined value of the first stage threshold and alternatively (1) a second stage deploy signal is generated if the velocity value exceeds the value of the first stage threshold and the second stage datum is stored, (2) a first stage deploy signal is generated if the velocity value exceeds the value of the first stage threshold and the second stage datum is not stored, and (3) no deploy signal is generated if the velocity value does not exceed the first stage threshold. For at least a portion of the predetermined clock count, the clock determined value of the first threshold exceeds the second threshold value.
摘要:
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.
摘要:
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.
摘要:
A dual stage occupant restraint deployment control provides a signal for first stage restraint deployment if, during a sensed possible crash event, a velocity value derived from a sensed acceleration and one or more immunity measures meet predetermined criteria. A second stage restraint deployment signal is provided if a crash severity measure derived from the time rate of change of the sensed acceleration meets predetermined criteria and the first stage activation signal has been generated. The method and apparatus ensure that the immunity criteria are met for both first and second stage deployment without repeated testing if the crash severity measure is vulnerable to non-crash accelerations produced by “misuse” events and rough road driving. The crash severity measure may be the time rate of change of the acceleration itself, an oscillation value derived this time rate of change of the acceleration with a velocity value requirement in the predetermined criteria, or a veloscillation value derived as a scaled sum of the oscillation value and the velocity value.
摘要:
A vehicle restraint control system provides sophisticated, adaptable control of occupant restraints through the use of a system level architecture to predict the nature of a crash event at the earliest possible time and an occupant injury model to tailor the restraint deployment in an adaptable way to characteristics of the protected vehicle occupant(s) and the nature of the crash event. The occupant injury model derives the potential for injury in a particular vehicle crash in real time as a function of occupant mass, vehicle interior stiffness and occupant impact velocity with respect to the vehicle interior. Peak vehicle crush zone velocity is used as a predictor of occupant impact velocity with the vehicle interior. Predicted occupant impact velocity is preferably adjusted in response to derived impact angle factor, which is derived from orthogonal lateral and longitudinal accelerometers in the vehicle occupant compartment. Vehicle longitudinal velocity may be integrated to predict occupant displacement, relative to the vehicle, as an additional factor used in the control system.