Automatic tuning of hexacopter attitude control systems with experimental validation

Unmanned Aerial Vehicles (UAV) have found many applications in the areas such as remote sensing, surveillance, filming, and other scientific research. Due to the fact that multirotor UAVs are unstable systems in nature, feedback control is paramount in ensuring successful flight missions. Hexacopter is a type of UAV that is capable of carrying heavier payload with increased stability while being less vulnerable to engine failures in comparison to quadcopters. This paper presents a novel approach to automatically tune hexacopter's PID controllers. An experimental test apparatus is designed to allow a hexacopter to be under relay feedback control, so that the input and output data can be safely collected for the estimation of its dynamics, followed by the PID controller design. A comparison study between the proposed method and Ziegler-Nichols is performed. Experimental results are obtained from a flight test in an outdoor environment against external disturbances to show the flight performance of the automatically tuned hexacopter.