Determining the direction of travel of an automotive vehicle from yaw rate and relative steering wheel angle
First Claim
1. 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; and
determining travel direction by comparing the accumulation of the forward net difference values and the accumulation of the backward net difference values.
2 Assignments
0 Petitions
Accused Products
Abstract
A method of using relative steering wheel angle of an automotive vehicle, vehicle yaw rate, and vehicle speed to determine whether the vehicle is traveling 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.
62 Citations
11 Claims
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1. 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:
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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; and determining travel direction by comparing the accumulation of the forward net difference values and the accumulation of the backward net difference values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. 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;
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measuring yaw rate; measuring vehicle speed; calculating one of a forward and a backward steering wheel angle from the vehicle speed and the yaw rate; calculating a difference between the relative steering wheel angle and the calculated one of the forward and the backward steering wheel angle; filtering the calculated difference; determining that the vehicle is traveling in the one of the forward and the backward directions based on the relative steering wheel angle, the yaw rate and the vehicle speed; and calculating an absolute steering wheel angle by adding the filtered difference to the relative steering wheel angle. - View Dependent Claims (10, 11)
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Specification