Evaluation of a simple pure pursuit path-following algorithm for an autonomous, articulated-steer vehicle

A pure-pursuit navigational control algorithm in an autonomous articulated-steer vehicle was studied as a simple method for path-following. Paths were created using GPS coordinates and the articulated-steer vehicle programmed to follow those paths using a pure-pursuit (goal-seeking) path-following algorithm. A GUI was developed in LabVIEW to read RTK-GPS coordinates, hydraulic pressure and articulation angle, and control the articulated-steer vehicle. The vehicle was tested for its ability to follow five different paths with two speeds and three control pulse signals. Path following succeeded with lower vehicle speed and full pulse signal for the straight and sinusoidal paths. Averaged path-following errors ranged from 6 to 19 cm as the turn radius increased. For a 90 degree turn, the path-following error was almost 80 cm. Path-following improvements could be made with faster control signal updates and a variable lookahead distance based on vehicle speed and required turning angle. It was concluded that the control architecture is a good basis for navigation of an articulated-steer autonomous vehicle.