A novel trajectory tracking methodology using structured adaptive model inversion for uninhabited aerial vehicles

Structured adaptive model inversion is used for designing adaptive flight control laws to track a target reference trajectory for autonomous UAVs. The mathematical model of the plant is refined by incorporating the known structured kinematic nonlinearities arising out of the gyroscopic coupling and the Coriolis terms thereby rendering the plant to have an “almost” exact nonlinear structure. For the aircraft problem, this presents us a model uncertain only in the aerodynamics and propulsive influences. The uncertain parameters are continuously estimated using an adaptation law. The control law presented realizes prescribed linear tracking error dynamics in the kinematic state vector. The overall closed loop dynamics is nonlinear. The controller designed using SAMI enforces the desired kinematic state error dynamics and guarantees tracking stability in the presence of model errors and unknown external disturbances. We show that the closed loop system is globally stable, although no claim can be made with regards to convergence of the adaptation parameters, as usual for controllers of this class