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.