Cascaded line-of-sight path-following and sliding mode controllers for fixed-wing UAVs

This paper describes a nonlinear controller for following references generated by a Line-of-Sight (LOS) guidance algorithm. Good performance is achieved even in disturbed conditions without integral action by controlling the vehicle's course instead of heading. A cascaded system architecture is employed and a uniform semiglobal exponential stability (USGES) proof is presented. Software-in-the-loop simulation results support the theoretical conclusions.