Development and testing of small aerial vehicles with redundant number of rotors

Multiple rotor Unmanned Aerial Vehicles (UAVs) are becoming ubiquitous due to simplicity of their construction, implementation and maintenance. Such UAVs are able to hover, take off and land vertically. In addition, it is relatively straightforward to design an on-board autopilot. In comparison with classical helicopters, multi-rotor aircrafts provide less dangerous testbed in urban and cluttered environments due to their small-size and light-weight blades. In this paper, we present two multi-rotor aircraft prototypes with payload up to one kilogram. In order to achieve greater payload capabilities and increase robustness due to motor failures, the presented prototypes have redundant number of rotors, one has six and other eight rotors. Furthermore, we propose algorithms for data fusion from gyroscopes, accelerometers, magnetometers and GPS for orientation and position estimation. Finally, control algorithms are designed in a multi-loop fashion and successfully tested on the prototypes. The developed UAVs are experimentally tested in real world outdoor environment conditions.