Trirotor mechatronic design and reduction of dynamic model inputs by aerodynamic forces identification

This paper outlines a mechatronic design and a remote measurement system of a trirotor unmanned aerial vehicle (UAV). Furthermore, with particular emphasis on the experimental aspect, this study presents also a real dynamic model with reduced inputs made by experimental aerodynamic forces/torques identification. The trirotor presents a real control challenge compared with the quadrotor system. Indeed, in contrast to the quadrotor, the trirotor presents a non-symmetric structure and it has an odd number of rotors which causes a yaw moment issue. The developed mechanical design and the actuators characteristics are then presented. Experimental tests show that we can have a reduced dynamic model. Indeed, with empirical manipulations we deduce some relations between drag torque and thrust forces. Such result allows us to reduce the trirotor developed model inputs. Finally, this study is a preliminary phase before the real-time control implementation.