Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

This paper describes the development of a trajectory controller for a trailer towed by an agricultural vehicle. The developed controller was tested by using an actual-size autonomous tractor and a trailer. The objective was to guide the trailer to a given destination by tracking a designed curve. Since field experiment had shown that the feed-forward controller could not guide the trailer to the given destination in backward run, feedback control designed based on locally linearized system around the given trajectory was introduced in order to stabilize the system and to improve its guidance accuracy. In this process, performances of feedbacks designed by pole-placement and optimal control were compared. Both feedbacks could guide the trailer to its given destination and no significant different in final positional error was observed between the two feedbacks tested. However, the maximum displacements in position, which occurred during backward parallel travel from the origin to (8, 3) m in Cartesian coordinates, were 14 cm using the pole-placement controller and 9 cm using the optimal controller. These results indicated that the feedback equipped with the optimal control showed the better trajectory tracking performance.