Trajectory Tracking Control of Unmanned Agricultural Tractor based on Slip Velocities Compensation

The lateral and longitudinal trajectory tracking control of the unmanned agricultural tractor based on slip velocities compensation is considered in this paper. The slip velocities are unknown but bounded. A proportional-integral (PI) observer is designed to estimate the slip velocities. The controllers dependent on the estimated slip velocities are designed. The stability of the closed-loop system is analyzed by the Lyapunov stability approach. The effectiveness and advantages of the designed controllers are illustrated by comparing with the controllers with slip velocities compensation based on an input observer and the controllers without slip velocities compensation in the simulation.