Development of Flight Dynamics Model for AH-25 Hybrid Unmanned Aerial Vehicle

Osichinaka C. Ubadike, Khalid K. Dandago, Mahmud S. Zango, Ameer Mohammed, Paul P. Okonkwo, T. D. Chollom, Bashir B. Muhammad, Christopher O. Adeboye


A good mathematical model accurately represents the behavior of a system. Although aircraft has complex dynamics, it is feasible to develop a robust model that could be used to design and analyze some of its essential components such as flight control system and simulator. To solve security challenges in the hinterlands and maritime domains, a hybrid Unmanned Aerial Vehicle (UAV), nicknamed ‘AH-25’, was designed by the Air Force Institute of Technology, Nigeria. In this work, the development of flight dynamics models of the vehicle is presented. The AH-25 UAV has the capability of operating in both fixed-wing and Vertical Take-Off and Landing (VTOL) modes for effective operations on land and maritime spaces. Therefore, models that capture the dynamics of the two distinct modes were obtained. The fixed-wing nonlinear model which was developed from first principle using Newton-Euler method was decoupled, trimmed and linearized to set it in a good shape for critical aircraft systems designs. On the other hand, the multicopter model developed by Beihang flight control group was adapted for modelling the VTOL mode. Simulation results showed that the models’ responses are a replica of the actual aircraft operations. Also, responses of the model to perturbations indicated that it is open-loop stable. Furthermore, the mean performance metrics of the fixed-wing model’s open-loop time response to various inputs were evaluated. The model was found to have a rise time of 2 s, 1.33% steady state error and a settling time of 40 s.


Flight dynamics; Mathematical model; Newton-Euler method; Unmanned aerial vehicle.

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G. Lee and C. O. Kim, Autonomous control of combat unmanned aerial vehicles to evade surface-to-air missiles using deep reinforcement learning, IEEE Access, 8, 2020, 226724-226736.

C. Kerr, R. M. Jaradat and N. U. I. Hossain, Battlefield mapping by an unmanned aerial vehicle swarm: applied systems engineering processes and architectural considerations from system of systems, IEEE Access, 8, 2020, 20892-20903.

R. Gill and R. D. Andrea, Computationally efficient force and moment models for propellers in UAV forward flight applications, Drones, 3(4), 2019, 77.

J. Hermann, R. Distasio and A. Tkatchenko, First-principles models for van der waals interactions in molecules and materials: Concepts, theory, and applications, Chemical Reviews, 117(6), 2017, 4714-4758.

M. Ryll, H. Bülthoff and P. Giordano, A novel overactuated quadrotor unmanned aerial vehicle: modeling, control, and experimental validation, IEEE Transactions on Control Systems Technology, 23, 2015, 540-556.

Z. Benić, P. Piljek and D. Kotarski, Mathematical modelling of unmanned aerial vehicles with four rotors, Interdisciplinary Description of Complex Systems, 14, 2016, 88-100.

E. A. Ahmad, A. Hafez, A. N. Ouda, H. E. H. Ahmad and H. M. Abd-Elkadir, Modelling of a small unmanned aerial vehicle, Advances in Robotics and Automation, 4(1), 2015, 1000126.

S. Islam, P. Liu and A. El Saddik, Robust control of four-rotor unmanned aerial vehicle with disturbance uncertainty, IEEE Transactions on Industrial Electronics, 62, 2015, 1563-1571.

J. Escareno, S. Salazar-Cruz and R. Lozano, Attitude stabilization of a convertible mini birotor, IEEE Conference on Computer Aided Control System Design, IEEE International Conference on Control Applications, IEEE International Symposium on Intelligent Control, Munich, Germany, 2006, 2202-2206.

J. Escareno, S. Salazar and R. Lozano, Modelling and control of a convertible VTOL aircraft, Proceedings of the 45th IEEE Conference on Decision and Control, San Diego, USA, 2006, 69-74.

A. Sanchez, J. Escareño, O. Garcia and R. Lozano, Autonomous hovering of a noncyclic tiltrotor UAV: modeling, control and implementation, IFAC Proceeding Volumes, 41(2), 2008, 803-808.

S. Saeed, A. B. Younes, C. Cai and G. Cai, A survey of hybrid unmanned aerial vehicles, Progress in Aerospace Sciences, 98, 2018, 91-105.

G. Chen, A. Liu, J. Hu, J. Feng and Z. Ma, Attitude and altitude control of unmanned aerial-underwater vehicle based on incremental nonlinear dynamic inversion, IEEE Access, 8, 2020, 156129-156138.

Y. Ke, K. Wang and B. Chen, Design and implementation of a hybrid UAV with model-based flight capabilities, IEEE/ASME Transactions on Mechatronics, 23(3), 2018, 1114-1125.

M. Allenspach and G. J. J. Ducard, Nonlinear model predictive control and guidance for a propeller-tilting hybrid unmanned air vehicle, Automatica, 132, 2021, 109790.

M. Mehndiratta, E. Kayacan, M. Reyhanoglu and E. Kayacan, Robust tracking control of aerial robots via a simple learning strategy-based feedback linearization, IEEE Access, 8, 2020, 1653-1669.

E. Small, E. Fresk, G. Andrikopoulos and G. Nikolakopoulos, Modelling and control of a tilt-wing unmanned aerial vehicle, 24th Mediterranean Conference on Control and Automation, Athens, Greece, 2016.

S. Kohno and K. Uchiyama, Design of robust controller of fixed-wing UAV for transition flight, International Conference on Unmanned Aircraft Systems (ICUAS), Orlando, USA, 2014, 1111-1116.

J. T. Vandermey, A tilt rotor UAV for long endurance operations in remote environments, Master Thesis, Massachusetts Institute of Technology, USA, 2011.

C. Papachristos, K. Alexis and A. Tzes, Design and experimental attitude control of an unmanned tilt-rotor aerial vehicle, 15th International Conference on Advanced Robotics (ICAR), Tallinn, Estonia, 2011, 465-470.

X. Fang, Q. Lin, Y. Wang and L. Zheng, Control strategy design for the transitional mode of tiltrotor UAV, IEEE International Conference on Industrial Informatics, Beijing, China, 2012.

S. Park, J. Bae, Y. Kim and S. Kim, Fault tolerant flight control system for the tilt-rotor UAV, Journal of Franklin Institute, 350(9), 2013, 2535-2559.

J. Kalpa Gunarathna and R. Munasinghe, Development of a quad-rotor fixed-wing hybrid unmanned aerial vehicle, Moratuwa Engineering Research Conference, 2018, 72-77.

M. Enomoto and Y. Yamamoto, Modelling, simulation and navigation experiments of unmanned aerial vehicle, IEEE International Conference on Mechatronics and Automation, Beijing, China, 2015.

W. Zhou, S. Chen, C. W. Chang, C. Y. Wen, C. K. Chen and B. Li, System identification and control for a tail-sitter unmanned aerial vehicle in the cruise flight, IEEE Access, 8, 2020, 218348-218359.

T. Haus, M. Orsag and S. Bogdan, Mathematical modelling and control of an unmanned aerial vehicle with moving mass control concept, Journal of Intelligent & Robotic Systems, 88, 2017, 219-246.

M. Huzmezan and J. Maciejowski, Original: english GARTEUR/TP-088-20 April 4, 1997, 1997.

Q. Quan, X. Dai and S. Wang, Multicopter Design and Control Practice: A Series Experiments Based on MATLAB and Pixhawk, Springer, 2020.


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