TY - JOUR TI - Control of a highly maneuverable multi-medium vehicle employing multi-plane propulsion DO - https://doi.org/doi:10.7282/T3QZ2F5N PY - 2018 AB - Multi-medium vehicles, which are capable of operating in multiple fluid mediums such as air and water, are a new paradigm in unmanned systems and the multirotor platform is an exceptional candidate configuration. Vehicles that can swim and fly are few and those that do exist are not maneuverable enough to accomplish complex missions. A multi-plane propulsion system is introduced that ensures seamless transition and sets forth some basic requirements and considerations on designing multi-medium multirotor vehicles which touches on hardware level components as well as firmware for the autopilot and the motor drivers. Five prototypes have been developed and these fully developed platforms adopted several control schemes that when aggregated, properly handle the continuous-discrete behavior that a multi-medium vehicle entails. The propulsion system was characterized and used to the determine the approximate drag coefficient at several pitch angles and speeds, which helped validate the pseudo-spherical drag model as a reasonable candidate for the overall dynamic model, especially at low speeds. From a controls standpoint, a standard multirotor controller employing a hierarchical PID controller was formalized. Next, this hierarchical controller was incorporated into a discrete-continuous system through a hybrid controller. Then, a gain scheduling algorithm was added by exploiting the discrete variables established by the hybrid system. Finally, a singularity-free quaternion representation was used such that a hierarchical hybrid quaternion controller with gain scheduling renders the vehicle highly maneuverable, agile and adept at each medium of operation. Several numerical simulations and experiments were conducted to assess vehicle performance with regard to maneuverability and convergence to a desired state. KW - Mechanical and Aerospace Engineering KW - Propulsion systems LA - eng ER -