A simple tractor-trailer backing control law for path following with side-slope compensation

Backing of a tractor-trailer system is a problem addressed in many literatures. It is usually solved using various nonlinear-based control methods, which are often not easy to implement or tune and do not consider the influence of side-slope. We propose a two-tier controller that is simple and intuitive, which directly controls the curvature of the trailer's trajectory. It allows the control input to be more directly related to path specification and handles path curvature discontinuity better. A side-slope compensator is designed upon the simple controller to prevent side-slope from deteriorating tracking performance. Experimental results are provided to illustrate the capability of this new algorithm applied to a full scale autonomous vehicle and trailer system in a real field environment using minimal sensing capability. Performance comparison between the compensated and uncompensated systems is also presented. Results demonstrate good performance on modest side-slope.