Development of a driver assistance system for long timber transportation trucks to improve tracking behavior

This paper introduces the newest development of a driver assistance system for log-hauling trucks, which transport long heavy timber from harvesting sites to distant storage yards or sawmills through off-road paths and on urban highway. Using suitable control strategies on the trailer steering unit, the long timber transportation can be more maneuverable and less hazardous. In this paper we proposed two control strategies for different driving conditions. The first one is a feedback control based on the measured articulation angles between the tractor truck and the payload as well as between the payload and the trailer. The simulation results show that the trailer could follow the trajectory of the tractor satisfactorily, if a normal road curvature was applied. On an extremely curvy road with a curvature larger than 0.1 (according to a turning radius of 10 meters), it was difficult to keep the trailer on the track of the tractor and an unstable situation could happen. As a solution to overcome this problem on extremely curvy narrow path in the forest, a feed-forward control strategy based on path prediction was investigated. Both control strategies have been applied on a 3-DOF linear yaw/plane model in computer simulations and presented promising results for the tests on real vehicles.