“…The position of the center of mass of the convertiplane-quadcopter in space is characterized by the X 0 , Y 0 ,Z 0 coordinates in a global Cartesian coordinate system and the three angles of rotation ϕ, θ, ψ-roll, pitch, and yaw angles around the axes of the local coordinate system CX 1 Y 1 Z 1 [3,[13][14][15] (Fig. 1).…”