Design and analysis of a mode-switching micro unmanned aerial vehicle

In this study, design and analysis of a mode-switching vertical take-off and landing (VTOL) unmanned aerial vehicle (UAV) with level flight capability is considered. The design of the platform includes both multirotor and fixed-wing (FW) conventional airplane structures; therefore named as VTOL–FW. The aircraft is modeled using aerodynamical principles including post-stall conditions. Trim conditions are obtained by solving constrained optimization problems. Linear analysis techniques are utilized for trim conditions in examining stability and controllability. The proposed method for control includes implementation of multirotor and airplane mode controllers and an algorithm to switch between them in achieving transitions between VTOL and FW flight modes. Thus, VTOL–FW UAV’s flight characteristics are expected to be improved by enlarging operational flight envelope through enabling mode-switching, agile maneuvers, and increasing survivability. Simulations and flight tests showed that VTOL–FW UAV demonstrates multirotor and airplane flight characteristics with extra benefits.