Method for detecting a rough road surface
AssigneeGeneral Motors Corporation
InventorsJenne-Tai Wang, Richard Jay Yun
Life of this patent
Estimating the term…
Abstract
A method for detecting a rough road surface upon which a vehicle is travelling, such detection being utilized by a crash sensing system for improving its immunity to inadvertent deployment during minor crash incidents. The onset of a crash event is sensed by an on-board accelerometer when the detected vehicle deceleration exceeds a predetermined deceleration threshold value. A rough road measurement is calculated as a function of the vehicle deceleration data and compared to a threshold boundary curve. A value of the rough road measurement exceeding the boundary curve is indicative of a rough road event.
Claims1
A method for detecting a rough road surface upon which a vehicle is traveling, the method comprising:
- providing a signal responsive to vehicle deceleration;
- sampling the vehicle deceleration signal at a predetermined sampling rate to obtain discrete values of deceleration;
- comparing discrete values of deceleration with a deceleration threshold to detect the onset of a crash event;
- computing absolute values of the discrete values of deceleration;
- determining difference values as a function of a difference between the absolute values and the discrete values of deceleration;
- determining rough road measurement values as an integral of the difference values;
- comparing the rough road measurement values with a predetermined time-dependent boundary curve;
- and
- indicating a rough road surface when the rough road measurement value exceeds a corresponding value of the boundary curve for the appropriate time into the crash event.
Dependencies are inferred from the claim text.