Delphi Technologies, Inc.

Delco Electronics Corporation

Joseph Thomas Dalum

Gerhard F Wessels

Sheri Lynn Patterson

Shyam V Potti

Michael K Walden

Gretchen Elizabeth Bubolz

Kristi Kay Reprogle

An improved method of using multiple point crash sensing and multiple sensor occupant position sensing for classifying a crash event and determining which restraints should be deployed. A central controller collects crash data from multiple crash sensors and combines severity characterization data from each of the multiple sensors to construct a characterization table or matrix for the entire system. Each possible crash event classification is represented by a characterization value mask, and the various masks are sequentially applied to the system characterization table until a match is found, with a match identifying the appropriate crash event classification. The classification decision, in turn, is used to determine which, if any, of the restraint devices should be deployed based upon the crash severity. Similarly, the controller collects data from various occupant position sensors to construct a characterization table or matrix for the occupant position detection system. Each possible occupant position sensor classification is represented by a characterization value mask, and various masks are sequentially applied to the table until a match is found, with a match identifying the appropriate occupant position status. The occupant position status, in turn, is used to determine which, if any, of the restraints may be deployed. The system also includes a centrally located crash sensor, and the controller constructs an intrusion table based on differences between the remote and central sensors. The intrusion classification is determined and combined with the crash classification and occupant position status to determine which restraints should ultimately be deployed.

Crash classification method and apparatus using multiple point crash sensing

An improved deployment method for a vehicular supplemental restraint system having an acceleration sensor and a restraint device to be deployed for occupant protection in a crash event, where the deployment threshold is adaptively adjusted based on the magnitude and rate of change of a filtered acceleration signal and the progression level of the sensed event. The deployment threshold is periodically adjusted based on the rate of change of the filtered acceleration signal, if the magnitude of the filtered acceleration signal is within a range specified for the progression level of the sensed event. The maximum amount of adjustment is also specified based on the progression level of the event. As a result, the deployment threshold tends to follow or track the filtered acceleration signal, particularly for non-deployment events where the magnitude of the filtered acceleration signal is within the specified range, thereby preventing deployment of the restraints. In deployment events, the magnitude of the filtered acceleration signal is more likely to fall outside the specified range, which minimizes feed-forward adjustment of the deployment threshold, thereby minimizing any delay in deployment of the restraints.

Restraint deployment control method with feed-forward adjustment of deployment threshold

An improved deployment method for a vehicular supplemental restraint system having an acceleration sensor and a restraint device to be deployed for occupant protection in a crash event, where the deployment is initiated when a filtered version of the acceleration signal exceeds a deployment threshold that is periodically adjusted based on one or more secondary measures of crash severity, including a vehicle speed measurement at the onset of the crash event, and the level of event progression. In a first embodiment, the vehicle speed measurement pertains to the ground or absolute speed of the vehicle at the onset of the crash event; in a second embodiment, the vehicle speed measure pertains to the vehicle speed relative to a detected obstacle at the onset of the crash event.

Restraint deployment control method with speed-dependent adjustment of deployment threshold

An improved deployment control method for a vehicular supplemental restraint system, wherein a deployment threshold is initially established at a predefined level, threshold adjustments are periodically determined in the course of the crash event based on one or more secondary measures of crash severity, and wherein the adjustments are applied to the deployment threshold at a time determined in relation to a predefined level of crash progression. In other words, deployment threshold adjustments are periodically determined based on identified characteristics of the crash signal and accumulated to form a net adjustment value, and the net adjustment value is not put into effect for purposes of deploying the restraints until expiration of a delay time initiated at a predefined level of crash progression. In a preferred implementation of the invention, the net adjustment value is put into effect for purposes of deploying the restraints prior to expiration of the delay time if certain secondary measures indicate that the crash is especially severe.

Restraint deployment control method having a delayed adaptable deployment threshold

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 implementation, 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.

Restraint deployment control with central and frontal crash sensing

An improved deployment method for a vehicular supplemental restraint system, wherein the existence of a rough road condition is indicated if a measure of crash severity obtained from an acceleration sensor exceeds a rough road threshold and the crash event reset criteria are subsequently met with no intervening deployment of the restraint device. The rough road indication is maintained for a timed period, and normal deployment of the restraint device is inhibited during the timed period unless the acceleration signal exceeds a minimum threshold and the measure of crash severity exceeds an additional deployment threshold which is initially higher than the normal deployment threshold. When the rough road condition is detected, a counter is initialized to a predefined value, and then periodically indexed so long as no potential crash event is in progress. If the counter is indexed to another predefined value prior to another rough road detection, the rough road condition is reset. A severe rough road will produce multiple initializations of the counter, resulting in a prolonged rough road indication, whereas a single rough road impact will result in a much shorter rough road indication. Raising the crash severity threshold in the presence of a rough road condition increases immunity to rough road events and allows the use of relatively aggressive reset criteria, while retaining the ability to properly deploy the restraints in a concatenated crash event.

Supplemental restraint deployment method providing rough road immunity

An improved deployment method for a vehicular supplemental restraint system having an acceleration sensor and a restraint device to be deployed for occupant protection in a crash event, where the deployment is initiated when a filtered version of the acceleration signal exceeds a deployment threshold that is periodically adjusted based on one or more secondary measures of crash severity and the level of event progression, the level of event progression being based on the value of a filtered acceleration signal relative to one or more predefined event progression thresholds. 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 crash event. Preferably, the level of event progression is determined by deriving a delta-velocity signal biased toward zero, 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 one or more secondary measures of crash severity. Threshold adjustments based on each of the secondary measurements are weighted and accumulated to determine the net threshold adjustment.

Restraint deployment control method having an adaptable deployment

An improved deployment method for a vehicular restraint system having an acceleration sensor and a restraint device to be deployed for occupant protection in a crash event, where a measure of the impact severity based on the difference between the cumulative change in filtered acceleration over a predefined window, and the slope of such cumulative change, is used to characterize the crash event and to adjust the deployment threshold accordingly. Low energy impacts having a soft onset, such as an impact with a gravel pile or a low speed fill frontal impact, will produce a relatively high value of the measure, referred to herein as the Soft Impact Index, or SI Index, in the early progression of the sensed event, whereas high speed impacts that require deployment will produce a relatively low SI Index in the early progression of the event. If the SI Index exceeds a threshold early in the progression of a sensed crash event, an offset is added to the .DELTA.V deployment threshold to reduce the likelihood of deployment, thereby increasing the system immunity to rough road and low velocity impacts. If the SI Index is below the threshold early in the progression of a sensed crash event, an offset is subtracted from the .DELTA.V deployment threshold to provide a more timely deployment of the restraints.

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Hartland, WI, United States of America

Joseph Thomas Dalum