An adaptive flight controller design for a tilt-prop fixed wing uav for all flight modes

© 2020, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.In this study, we propose an autonomous flight control strategy (which is valid for all flight modes including vertical flight, hover, and level flight) for a vertical takeoff and landing capable, tilt-prop, fixed wing, tricopter unmanned aerial vehicle. In the inner loop of proposed hierarchical architecture, desired control forces and moments are generated using adaptive control theory, and these forces and moments are realized by tricopter motors and aerodynamic control surfaces with an introduced control allocation methodology. In the outer control loop, a pitch offset command is introduced so that the strategy for transition from hover to level flight (and vice versa) can be adjusted. Using this pitch offset command, one may follow the transitioning path on which lift-to-drag ratio becomes maximum that makes the transitioning maneuver cost efficient. Outer control loop also generates the desired attitude commands and continuous front motor tilt angle using reference velocity commands. Hence, no switch is required in the controller while operating between the flight modes. The success of the proposed control architecture is illustrated through numerical simulations on a Hi-Fi nonlinear tricopter model

Nonlinear optimal adaptive transition control of a tolt-prop VTOL UAV

In this work, transition corridor determination and transition control of a Tilt-Prop Vertical Takeoff and Landing aircraft problem is addressed. Non-linear flight dynamics model of the aircraft is generated using the software Generic Air Vehicle Model. Transition corridor is estimated by using the constructed model and analyzed in terms of power consumption and flight efficiency. Automatic transition flight control system deals with fully automated transition control of Tilt-Prop UAV including uncertainties in system modeling and system parameters. Control system is integrated to a 6-DoF simulation environment. Different transition maneuvers are performed and results are discussed in terms of power consumption and efficiency. Efficiency of the transition controller is illustrated through simulations over the determined transition corridor. It is planned to integrate the nonlinear adaptive transition controller to the flight computer of the aircraft to validate the transition corridor with flight tests and perform automated transition to forward flight. Copyright Statement The authors confirm that they, and/or their company or organization, hold copyright on all of the original material included in this paper. The authors also confirm that they have obtained permission, from the copyright holder of any third party material included in this paper, to publish it as part of their paper. The authors confirm that they give permission, or have obtained permission from the copyright holder of this paper, for the publication and distribution of this paper as part of the ERF proceedings or as individual offprints from the proceedings and for inclusion in a freely accessible web-based repository