  The paper solves the problem of tracking control of a quadrotor with
unmeasurable pitch and roll angles based on the geometric approach with the use
of the enhanced extended observer and the internal model. The proposed approach
makes it possible to ensure the movement of a quadrotor in a horizontal plane
along a trajectory given in the form of a sinusoidal or second-order polynomial
function with semiglobal asymptotic convergence of the tracking errors to zero.
