US 12,296,905 B2
Techniques for controlling autonomous 4WS vehicles
Joshua Rands, Westminster, CO (US); Justin Creaby, Westminster, CO (US); and Brandon Sights, San Marcos, CA (US)
Assigned to Trimble Inc., Westminster, CO (US)
Filed by Trimble Inc., Westminster, CO (US)
Filed on Oct. 27, 2022, as Appl. No. 17/975,414.
Prior Publication US 2024/0140527 A1, May 2, 2024
Int. Cl. B62D 7/15 (2006.01); A01B 69/04 (2006.01); A01B 69/08 (2006.01); B62D 7/14 (2006.01); B62D 15/02 (2006.01); G01S 19/39 (2010.01)
CPC B62D 7/159 (2013.01) [A01B 69/008 (2013.01); B62D 7/142 (2013.01); B62D 15/021 (2013.01); G01S 19/393 (2019.08)] 20 Claims
OG exemplary drawing
 
1. A method for determining the heading of a four wheel steering (4WS) vehicle, comprising:
measuring a current front wheel steering angle;
measuring a current rear wheel steering angle;
calculating the 4WS vehicle's dynamic pivot point from the current front wheel steering angle and current rear wheel steering angle;
determining a distance between the pivot point and a Global Navigation Satellite System (GNSS) antenna;
determining a time delay in the form of the distance between the GNSS antenna and the pivot point divided by the current vehicle horizontal velocity;
determining a vehicle yaw rate for the 4WS vehicle;
multiplying the time delay by a vehicle yaw rate to obtain a result;
adding the result to a GNSS antenna heading to give a true heading, the true heading corresponding to the heading at the pivot point of the 4WS vehicle; and
controlling a steering of the 4WS vehicle based on the true heading.