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Path Tracking of a UAV via an Underactuated H∞ Control Strategy

In this study, a nonlinear robust control strategy designed for underactuated mechanical systems is proposed in order to solve the path tracking problem for a quadrotor unmanned aerial vehicle. An underactuated nonlinear controller based on the six degrees of freedom dynamic model is designed to control the helicopter attitude and altitude in the inner-loop. The outer-loop control is performed using a model-based predictive controller ( MPC ) to track the reference trajectory. The robust performance achieved with the proposed control strategy is checked by simulation in the presence of aerodynamic disturbances, unmodelled dynamics and parametric uncertainties.