Development of a B-Spline-based Path Planner for Semi-Autonomous Field Guidance

This paper presents a B-spline based path planning approach for agricultural guidance applications which is able to handle successively generated trajectories. Additionally, the lateral controller which was used to calculate the steering angle is described and the method by which the required parameters were determined is introduced. We explain stepwise how the output of a perception system is used to determine the control points for the planner and why B-splines and Bézier curves are used to model the trajectory. Moreover, it is shown how the inputs for the path tracker are derived from the B-splines. The approach was implemented on two different farm machines where the performance of the planning and control approach were evaluated. Furthermore, both algorithms were used to build a windrow guidance demonstrator. Keywords—B-splines, agricultural guidance, lateral control, Path planning, trajectory planning