Trajectory tracking strategy of quadrotor with output delay

A nonlinear output-feedback control strategy is devised using delayed-output observer for an underactuated quadrotor to track a given reference trajectory. The presented strategy consists of a delayed-output observer. A two-step observation algorithm is used to reconstruct the system conditions to compose the presented observer. By utilizing the presented strategy, the problem of time-delay is solved. The dynamic model of the quadrotor is presented firstly. To guarantee that the observation of the specific delay factors in the system is exponential convergent to zero under the given conditions. The advantages of the presented strategy are its practicability and extensive applications. Numerical results are presented for a practical tracking case under arbitrarily large initial and desired conditions.