Trajectory Tracking of Underactuated VTOL Vehicles Using Double Filtered Signals

A state feedback control strategy for underactuated vertical take-off and landing vehicles is proposed to track the desired position and attitude trajectory. To achieve exponential convergence in all state variables of 6 degrees-of-freedom nonlinear dynamical model, double filtered signals (DFS) for translational and rotational dynamics are introduced, then the thrust force controller and torque controller are designed respectively. DFS based control design takes the advantage of reducing the requirement of the desired trajectory and it is strictly proved that all signals of the original system are bounded and the tracking errors can be made arbitrarily small by tuning controller gains. The effectiveness of the obtained results is demonstrated by means of simulations.