Analysis of a Multirotor UAV with Tilted-Rotors for the Purposes of Disturbance Rejection

The station-keeping performance of multirotor UAVs in a turbulent wind field is of importance for a number of applications where close proximity to objects in the environment is expected. In this work, a tilted-rotor UAV which is able to generate horizontal forces without attitude changes is analysed over a range of wind speeds expected to be encountered in operation. The analysis process integrates aerodynamic models obtained from experimental tests, and compares the magnitude and bandwidth of the horizontal thrust force able to be generated by the tilted-rotor concept against a conventional UAV with rotors oriented along a common axis. It is found that while the tilted-rotor UAV is not able to generate as much thrust in the horizontal plane compared to conventional actuation involving attitude changes, it is able to offer an actuation bandwidth one order of magnitude greater than that of conventional actuation. The synergistic combination of both actuation methods on a single UAV thus has the potential to lead to improved station-keeping performance, while reducing high frequency attitude corrections.