Communications: electrical – Land vehicle alarms or indicators – Of collision or contact with external object
Reexamination Certificate
1999-09-24
2001-03-06
Tong, Nina (Department: 2736)
Communications: electrical
Land vehicle alarms or indicators
Of collision or contact with external object
C340S903000, C307S010100, C701S045000, C280S735000, C180S282000
Reexamination Certificate
active
06198387
ABSTRACT:
TECHNICAL FIELD
This invention relates to automotive passenger restraint systems, and more particularly to a control method that differentiates deployment events from non-deployment events in a restraint system having both central and frontal crash sensors.
BACKGROUND OF THE INVENTION
In general, automotive passenger restraint systems perform a number of functions including acceleration sensing, signal processing and analysis, and deployment of one or more restraint devices such as frontal or side air bags and seat belt pretensioners in response to a sensed crash event. Typically, an acceleration signal is monitored to detect a potential crash event, and then filtered or integrated over the course of the crash event to produce a velocity change or &Dgr;V signal. If the &Dgr;V signal exceeds a threshold, the crash event is determined to be sufficiently severe to warrant deployment of restraints. The threshold is typically time-dependent, and is calibrated based on data logged for different types of crash events, as well as data logged during rough road driving. Multiple distributed crash sensors are sometimes used in order to obtain faster deployment decisions and to distinguish a localized crash event from a full frontal crash event. For example, the system may include a central crash sensor located in or near the passenger compartment and one or more remote sensors located near the front corners of the vehicle.
A problem with the above-described approach, with single or multiple sensors, is that it is often difficult to synchronize the time progression of the crash (that is, the event clock or timer) with the actual crash event. Various algorithms have been developed for determining if and when the event clock should be reset to improve synchronization. As a result, it can be difficult to distinguish between deployment events and non-deployment events, particularly in the first portion of the sensed event.
A related problem in systems with multiple crash sensors is that it is difficult to quickly and reliably correlate the information from the various sensors. In particular, it is difficult to reliably distinguish between a localized crash event for which deployment is desired and a localized impact (such as a deer impact or an abuse event) for which deployment is not desired.
SUMMARY OF THE INVENTION
The present invention is directed to an improved restraint deployment control with central and frontal acceleration sensing, where the deployment is initiated when a filtered version of the central acceleration signal exceeds a deployment threshold that is periodically adjusted based on secondary measures of crash severity, the secondary measures being determined at least from the frontal acceleration signal. The threshold adjustment also takes into account the progression level of the crash event, as judged by the filtered version of the central acceleration signal.
In a preferred embodiment, the deployment threshold is set to a relatively high default level during periods of inactivity to provide good immunity to rough road impacts, while providing timely deployment for high speed crash events, and is periodically adjusted from the default level in the course of a sensed event. Preferably, the level of event progression is determined by deriving a &Dgr;V signal from the central acceleration sensor, and comparing such signal to a set of predefined event progression thresholds. At each level or stage of the event progression, the deployment threshold is adjusted within predefined boundaries based on central and frontal crash severity indications. Threshold adjustments based on the central and frontal severity indications are individually limited and then accumulated to determine the net threshold adjustment. In a particularly advantageous embodiment, the secondary measurements include an offset measure based on the difference between two frontal &Dgr;V signals, and corner crush measures based on differences between the frontal and central &Dgr;V signals.
REFERENCES:
patent: 5424583 (1995-06-01), Spies et al.
patent: 5493493 (1996-02-01), Shibata et al.
patent: 5508918 (1996-04-01), Gioutsos
patent: 5737224 (1998-04-01), Jeenicke et al.
patent: 5777225 (1998-07-01), Sada et al.
patent: 5801619 (1998-09-01), Liu et al.
patent: 5802480 (1998-09-01), Shiraishi
patent: 5872313 (1999-02-01), Zarabadi et al.
patent: 5884203 (1999-03-01), Ross
patent: 5889207 (1999-03-01), Lutz
patent: 5969599 (1999-10-01), Wessels et al.
patent: 0836073 (1998-04-01), None
Dalum Joseph Thomas
Wessels Gerhard F.
Delphi Technologies Inc.
Funke Jimmy L.
Tong Nina
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