System and method for sensing soil-and curb-tripped rollover events

A method of controlling a restraint device in a vehicle during a crash, the method comprising:

• generating a first signal indicative of a lateral acceleration of the vehicle;
• determining a second signal from the first signal;
• retrieving a trip-rollover region representing lateral accelerations and changes in lateral accelerations based on the first and second signals;
• generating a third signal indicative of a roll rate of the vehicle;
• determining a fourth signal from the third signal;
• retrieving a plausibility region representing roll rates and changes in roll rates based on the third and fourth signals;
• comparing the first and second signals to a soil-trip threshold;
• comparing the first and second signals to a curb-trip threshold;
• activating the restraint device when the first and second signals are in the trip-rollover region, and when the third and fourth signals are in the plausibility region, wherein the restraining device is activated based on a soil-trip rollover crash when the first and second signals cross the soil-trip threshold, and is activated based on a curb-trip rollover crash when the first and second signals cross the curb-trip threshold.

A system for controlling a restraint device in a vehicle during a crash, the system comprising:

• a lateral condition sensor configured to sense a lateral condition experienced by the vehicle;
• a classifier configured to classify the crash based on the lateral condition;
• a roll sensor configured to sense a roll condition experienced by the vehicle;
• a comparator configured to compare the sensed roll value with a plausibility region;
• a signal generator configured to activate the restraint device based on the classified crash and when the roll value falls within the plausibility region;
• a processor configured to determine a processed lateral condition from the lateral condition, wherein the processed condition comprises at least one of a derivative of the lateral condition, a slope of the lateral condition, and a rate of change of the lateral condition;
• and
• a memory operable to store a plurality of lateral condition regions derived from calibrating a set of lateral conditions and a set of processed lateral condition,
• wherein the comparator is further configured to compare the sensed lateral condition and the processed lateral condition with the lateral condition regions, and
• wherein the processor is further configured to indicate a trip-rollover type if the sensed lateral condition and the processed lateral condition fall in one of the lateral condition regions, wherein the trip-rollover type comprises a soil-trip rollover and a curb-trip rollover.

A method of controlling a restraint device in a vehicle during a crash, the method comprising:

• sensing a lateral condition;
• determining a processed lateral condition based on the lateral condition, the processed lateral condition including at least one of a derivative of the lateral condition, a slope of the lateral condition, and a rate of change of the lateral condition;
• classifying the type of crash based on the lateral condition and the processed lateral condition;
• comparing the lateral condition and the processed lateral condition to a soil-trip threshold;
• comparing the lateral condition and the processed lateral condition to a curb-trip threshold;
• activating a restraint device based on a soil-trip rollover crash when the lateral condition and the processed lateral condition cross the soil-trip threshold and based on a curb-trip rollover crash when the lateral condition and the processed lateral condition cross the curb-trip threshold.

A method of classifying a type of vehicle crash, the method comprising:

• sensing a set of lateral conditions;
• determining a set of processed lateral conditions based on the set of lateral conditions, each processed later condition including at least one of a derivative of the lateral condition, a slope of the lateral condition, and a rate of change of the lateral condition;
• defining a plurality of lateral condition regions based on the set of lateral conditions and the set of processed lateral conditions;
• comparing each sensed lateral condition and each processed lateral condition with the lateral condition regions;
• and
• classifying the crash as a trip-rollover type crash if a sensed lateral condition and a processed lateral condition fall in one of the lateral condition regions, wherein the trip-rollover type crash includes a soil-trip rollover and a curb-trip rollover.