Robust Path Following of the Tractor-Trailers System in GPS-Denied Environments

Abstract

This letter reports a general path following framework for the tractor-trailers system in Global Positioning System (GPS)-denied environments. Compared to existing methods, this approach prioritizes a robust, cost-optimized, and easy-to-implement solution. First, to achieve accurate path following, a force sensor is subtly introduced to capture the impact of an arbitrary number of trailers and varying payloads on the tractor dynamics. A robust controller is then designed on the basis of a newly derived tractor dynamic model and the lateral force compensation. Second, a novel visual-inertial estimator, which explicitly considers the nonlinear velocity dynamics, is developed to allow real-time translational velocity and position estimation for dynamic feedback control. It is rigorously proved by the Lyapunov theory that the stability of the proposed estimation and control system is guaranteed. Full-scale experiments are conducted to demonstrate the feasibility of the approach.