Determining the direction of travel - forward or backward - of an automotive vehicle

摘要

A method of using relative steering wheel angle of an automotive vehicle, vehicle yaw rate, and vehicle speed to determine whether the vehicle is travelling forward or backward. Forward and backward steering wheel angles are calculated from vehicle speed and yaw rate (22). A difference between relative steering wheel angle and forward steering wheel angle (10), and a difference between relative steering wheel angle and backward steering wheel angle (12) are calculated. The difference between relative steering wheel angle and forward steering wheel angle is filtered (14), and a difference between the filtered and the unfiltered difference between relative steering wheel angle and forward steering wheel angle is calculated to obtain a forward net difference (18). The difference between relative steering wheel angle and backward steering wheel angle is filtered (16), and a difference between the filtered and the unfiltered difference between relative steering wheel angle and backward steering wheel angle is calculated to obtain a backward net difference (20). While repeatedly performing the foregoing steps, forward net difference values derived from the forward net differences are accumulated (24), and backward net difference values derived from the backward net differences are accumulated (26). The travel direction is determined by comparing the accumulation of forward net difference values and the accumulation of backward net difference values (28). Absolute steering wheel angle and road bank angle can also be calculated.