Automated lane guidance of commercial vehicles

This paper is concerned with automated lane guidance of heavy vehicles in the context of automated highway systems. Emphasis is on tractor-semitrailer combinations. Vehicle models are formulated in both the vehicle coordinate frame and the road coordinate frame. The model in the latter frame is appropriate for dynamical analysis and controller design since the lateral error is measured relative to the road. The vehicle speed and the look-ahead distance, i.e., the location of lateral error sensor relative to the tractor´s center of gravity, significantly affect the open loop dynamics from the front wheel steering angle to the lateral error. This aspect is studied by linear analysis. Two classes of lateral controllers are presented: one class is designed based on linear H_∞ loop shaping methods and the other is based on nonlinear robust control and adaptive control. Simulation results are presented to verify the linear and nonlinear designs