Dynamic Inversion and Gain-Scheduling Control for an Autonomous Aerial Vehicle with Multiple Flight Stages

Several configurations of unmanned aerial vehicles (UAVs) were proposed to support different applications. One of them is the tailsitter, a fixed-wing aircraft that takes off and lands on its own tail, with the advantage of high endurance from fixed-wing aircraft and not requiring a runway during takeoff and landing as helicopters. However, the flight envelope of these vehicles contains multiple flight stages, each one with its own particularities and requirements, which makes its control more complex and hampers its use as an autonomous vehicle. Therefore, this paper presents an autopilot structure for a new tailsitter UAV, called Autonomous VerticAL takeOff and laNding (AVALON), with focus in the use of dynamic inversion and gain-scheduling control. Moreover, the AVALON’s equations of motion are described and used to reproduce a simulation environment. The results show the feasibility of these control techniques, with a convergence of the aircraft attitude and velocity during all the different flight stages of AVALON’s operation. We also compared its behaviour with PI controllers that calculates the control surfaces deflections with the attitude, and the use of dynamic inversion with gain-scheduling shows smaller errors in most of the flight stages, with the exception of the horizontal and landing stages.