Design and Development of a Quad-Shrouded-Rotor Micro Air Vehicle

A quad-rotor micro air vehicle has been designed and built, using 4-inch-diameter shrouded rotors. Extensive testing of various rotors, fabricated in-house, has been conducted in both the shrouded and unshrouded ('open') conditions to investigate the aerodynamics of rotors at this scale and to obtain the optimum rotor geometry for the vehicle. Parameters investigated included blade camber, number of blades (rotor solidity), collective pitch angle and rotational speed. Commercially-available propellers of similar scale were also obtained and tested, to compare with the performances of the in-house rotors. The performance of the individual rotors appeared promising for application on the vehicle; however, when assembled together, drastic reductions in performance were observed during benchtop testing of the quadrotor aircraft. A control algorithm and hardware have been implemented for mixing the pilot inputs to the different rotors and for controlling the aircraft; integration of the inertial measurement unit for feedback into the control loop remains to be implemented.