Flight Controller Design and Testing for Tailless Aircraft with Thrust Vectoring

Abstract

A digital fly-by-wire control system is designed and results from flight testing are presented for a radio controlled electric ducted fan model of the Euro fighter Typhoon. The controller is gain scheduled on dynamic pressure and throttle setting and allows the pilot to command pitch, roll, and yaw rates directly. The controller also attempts to hold altitude, heading, and pitch angle when the pilot centers the sticks. An ArduPilot microcomputer incorporating accelerometers, gyroscopes, magnetometers, GPS, and an airspeed sensor is installed to measure the state of the aircraft and calculate control signals using feedback. The results of wind tunnel testing of the aircraft in both conventional and tailless con gurations are also presented. These tests informed the creation of a model of the aircraft's dynamics that is used in the design of the controller. Linear quadratic optimal control design is used to design a controller for individual operating points. Interpolation is then used to determined gain values at arbitrary flight conditions. This controller is implemented in new code running on the ArduPilot computer and used in a series of flight tests. Lastly, the pilot's impressions of the aircraft's handling are presented.