Aerobatic maneuvers of a compound rotorcraft at high advance ratios - Flight path generation and dynamic simulation

A flight path generation algorithm that calculates control inceptor commands required for aerobatic maneuvers was tailored for time-sensitive maneuvers and further generalized. This algorithm was first developed in previous work for flight path generation with a distance-based objective function; the algorithm now features an alternate mode with a time-based objective function subject to load factor constraints. Nonlinear dynamic inversion (NLDI) is the control architecture used for a compound H-60 rotorcraft with redundant control schedules. The inner loop of the NLDI controller regulates bank angle, pitch attitude, and yaw rate, while the outer loop commands longitudinal and vertical acceleration. This controller was used in recent aerobatic work but had some deficiencies in tracking the acceleration commands. The controller's acceleration tracking has been improved in this study. Three aerobatic maneuvers are examined in simulation: Weaving Pull-up (WPU), Combat Break Turn (CBT), and Zoom and Boom (ZAB). This study seeks to illustrate the following: present updates to the flight path tool used to generate aerobatic maneuver commands for non-piloted simulations, introduce additional aerobatic maneuvers for compound rotorcraft, assess the improved NLDI controller's performance in tracking commands, and examine the compound rotorcraft in complex maneuvers at high advance ratios.