Patent ID: 6141605
Filing Date: 2000-10-31
Classification: B60T,B60W

Abstract:
A method of using relative steering wheel angle of an automotive vehicle, yaw rate of the vehicle, and speed of the vehicle to determine whether the vehicle is traveling in a forward direction or a backward direction, the method comprising the steps of:measuring relative steering wheel angle;measuring yaw rate;measuring vehicle speed;calculating a forward steering wheel angle from the vehicle speed and the yaw rate;calculating a backward steering wheel angle from the vehicle speed and the yaw rate;calculating a difference between the relative steering wheel angle and the forward steering wheel angle;calculating a difference between the relative steering wheel angle and the backward steering wheel angle;filtering the difference between the relative steering wheel angle and the forward steering wheel angle;calculating a difference between the filtered and the unfiltered difference between the relative steering wheel angle and the forward steering wheel angle to obtain a forward net difference;filtering the difference between the relative steering wheel angle and the backward steering wheel angle;calculating a difference between the filtered and the unfiltered difference between the relative steering wheel angle and the backward steering wheel angle to obtain a backward net difference;while repeatedly performing the foregoing steps, accumulating the forward net difference values derived from the forward net differences, and accumulating the backward net difference values derived from the backward net differences; anddetermining travel direction by comparing the accumulation of the forward net difference values and the accumulation of the backward net difference values.