A Novel Concept for VTOL Platform Combining Variable Pitch Main Rotor and Quadrotor Configurations

Unmanned Aerial Vehicles (UAVs) have numerous applications in military, commercial and hobby fields. Among these vehicles, drones with vertical take-off and landing (VTOL) capability have attracted more attention due to their specific capabilities such as better maneuverability and hover flight. In recent years, numerous concepts emerged which trying to propose new configurations to enhance UAVs performance. In this paper, we propose a novel concept which integrates single main rotor helicopter and quadrotor structure to overcome some difficulties exist in those applications. This suggested configuration, include a variable pitch main rotor equipped with four smaller counterrotating rotors to overcome its opposite torque (instead of a tail rotor in helicopters) and also sustain a portion of the UAV weight which make it possible to use a smaller main rotor. This design preserves maneuverability of helicopters, while eliminates tail rotor power loss and its asymmetric lateral force and also enhances the flight stability and maneuverability by properly using other four rotors’ thrusts. Preliminary dynamic modeling and control system design are presented in the text and the results show that this idea can be investigated further. The next steps are planned to be studied in next researches.