Robust output tracking control for a velocity-sensorless vertical take-off and landing aircraft with input disturbances and unmatched uncertainties

YIn this paper, we develop a nonlinear controller to achieve output tracking for a nonminimum phase vertical take-off and landing aircraft without velocity measurements. To attenuate the effects of input disturbances and unmatched uncertainties, auxiliary control inputs are introduced in the state observer. Then by taking the aircraft lateral movement into consideration, a control law is proposed to force the vertical take-off and landing aircraft to asymptotically track the desired trajectories even in the presence of unexpected changes of the trajectories, while driving the unstable internal dynamics to follow the bounded and causal ideal internal dynamics via the stable system center method. Numerical simulation results illustrate the effectiveness and robustness of the proposed controller.