Effects of actuator dynamics on disturbance rejection for small multi-rotor UAS

Small multi-rotor unmanned aircraft systems have many potential applications within urban environments, but large-scale turbulence common in such environments can represent a significant difficulty for their operation. Actuator dynamics affect on an aircraft's ability to track attitude commands and may influence its ability to reject disturbances. This paper presents a study of the effects of actuator dynamics on a small quadrotor model generated through system identification. A performance-based optimisation that minimises attitude-tracking errors in the presence of disturbances is used. System identification of different combinations of actuator components is performed, and the data is used to investigate the effects of high-frequency actuator dynamics on control-system phase lag and to determine their impact on disturbance rejection performance.