Method of determining the lateral velocity of a vehicle during abnormal driving situations

摘要

Disclosed is a method to determine a vehicle's lateral velocity during abnormal driving situations of a vehicle during controlled side-impact or rollover crash tests that involve the pulling of a vehicle sideways into an object. A high-resolution, low-range, lateral accelerometer is integrated to determine the lateral velocity. Furthermore, is a method to initiate the integration of the acceleration signal and a method to stop and reset the integration. The method recognizes special conditions associated with abnormal driving situations like controlled crash tests, and therefore will not be active during normal operating conditions. The method also includes a means to handle offset tolerances associated with accelerometers by finding the sensor's zero-g point while the vehicle is at rest.

主权项

1. A method of determining a lateral velocity during abnormal driving situations of a vehicle, such as during a controlled vehicles crash test, from a lateral acceleration signal, the method comprising:
detecting an abnormal driving situation by at least one of the following events;
a) vehicle speed information delivered from CAN is lower than a predescribed value,b) number of revolutions of an engine is lower than a predescribed value or the engine is off,c) number of revolutions of vehicle wheels are lower than a predescribed value,d) transmission gear is consistent with a prescribed test set-up,e) a parking brake is engaged, andf) vehicle travel distance during a current key cycle is lower than a predescribed value; calculating an initial zero-g-point value from the lateral acceleration signal if an abnormal driving situation is detected; detecting a lateral acceleration signal over a minimum threshold and start an integration of the lateral acceleration signal and compare an average value calculated from the integrated lateral acceleration signal with the calculated initial zero-g-point value; and if the average value differs from the calculated initial zero-g-point value by more than a predefined threshold use the actual integrated lateral acceleration signal as valid lateral velocity and continue the integration until a predefined stopping condition has been reached.