Robust Nonlinear Model Predictive Control Based Visual Servoing of Quadrotor UAVs

In this paper, a robust nonlinear model predictive control (NMPC) scheme is proposed for the visual servoing of quadrotors subject to external disturbances. To decouple the image kinematics, the image features are properly defined in the virtual camera plane. By combining the image kinematics with the quadrotor dynamics, a robust NMPC based IBVS algorithm is developed to ensure the satisfaction of physical and visibility constraints, where the tightened state constraints are constructed for handing external disturbances. The sufficient conditions on guaranteeing recursive feasibility of the proposed NMPC algorithm are derived. Furthermore, we theoretically show that the closed-loop system is input-to-state practically stable (ISpS). Finally, the simulation studies and experiment tests are conducted to verify the efficacy of the proposed method.