Robust Control Based on DOBC for Improving Lateral String Stability of Truck Platooning

Truck platooning means that two or more trucks are driven with short inter-vehicle distances. It is important to guarantee string stability in order to maintain the platoon. However, heavy trucks are not only complex in dynamic characteristics compared to passenger cars because the tractor and trailer are connected to the kingpin and have large volume and mass, but are also vulnerable to disturbances such as road banks and crosswinds. In lateral control, model uncertainty and disturbance deteriorate the path-tracking performance to follow the preceding vehicle, resulting in loss of lateral string stability. In this paper, to solve this problem, a robust controller based on linear disturbance observer-based control (DOBC) was designed to compensate for model uncertainty and lateral disturbance during path-tracking control for the platooning. For disturbance estimation, a Kalman filter-based disturbance observer (DOB) was designed using a 3 DOF articulated vehicle model. Model uncertainty and disturbance were defined as the 'lumped' disturbance. A disturbance compensator was applied to the path-tracking controller using a pure pursuit algorithm. The proposed controller was validated on the Yeoju smart highway testbed using semi-trailer trucks, Hyundai Xcient.