A Model of Aerodynamic Loads on the Unmanned Aerial Vehicle Control Surface for the Ground Testing

Aeronautical and Space-Rocket Engineering


Аuthors

Kovalev M. A.*, Kirillov A. V.**, Sitnikov V. V.***

Samara National Research University, Moskovskoe shosse, 34, Samara, Russia

*e-mail: kovalev.ma@ssau.ru
**e-mail: aleksey.v.kirillov@ssau.ru
***e-mail: vlsitnikovvl@gmail.com

Abstract

Development of the unmanned aviation is being followed by the increased requirements for reliability and safety, which in turn increases the importance of the control systems ground-based testing. Traditional approaches to bench testing do not account for the effects of aerodynamic forces on the control surfaces inflight, which reduces the accuracy of the results and leads to the need for expensive and risky flight experiments in the early stages of the tryout. Developing the systems capable of the aerodynamic loads physical imitation in ground conditions is a pressing scientific and engineering problem oriented to semi-natural simulation techniques updating while testing.
The purpose of the article consists in developing and verifying mathematical model of the aerodynamic loads simulation system (ALSS) for the aircraft type unmanned aerial vehicles (UAV) ailerons system intended for application as a part of benches for semi-natural testing. The model should ensure control force computing with account for the entire complex of factors, determining the aerodynamic moment on the aileron surface in real flight. The aerodynamic loads simulation on other UAV control surfaces may be executed in a similar way.
The work is based on the methods of theoretical mechanics, aerodynamics, and automatic control theory. The ALSS structural diagram, including the UAV automatic control system (ACS), load controller, electromagnetic force loader, kinematic force transmission system to the aileron, and feedback sensors was developed. Mathematical dependencies for the aerodynamic force computing were derived. A key aspect is accounting for the UAV's spatial position by transforming the relative airspeed vector from the earth-fixed coordinate system to the body-fixed system with rotation matrices, which allows determining the effective angle of attack for the aileron. The system dynamics, including the loader inertia, are described by a second-order oscillatory link differential equation. Simulink visual modeling environment, in which the detailed module structure, including atmospheric blocks, coefficients computing, coordinates transformation and drive control, was developed, was employed for the model realization and its analysis.
As the result of the work, the ALSS comprehensive mathematical model was created. A computational experiment was conducted for six different flight modes, differing in speed, altitude, as well as the presence of the wind speed and direction. Time dependencies of the force generated by the load simulator in response to a given law of the aileron deflection angle change were obtained. Simulation results demonstrated:
1) Quadratic dependence of the force on the flight speed;
2) Load reduction with the altitude increasing due to the in air density drop;
3) Significant wind impact, leading not only to the speed magnitude changing but to a shift in the effective angle of attack as well, which confirms correctness of the introduced coordinate transformations;
4) Transient process characteristic corresponding to an oscillatory link with the acceptable overshoot. All model reactions are physically justified, and demonstrate adequate system behavior under changing conditions.
The developed ALSS system mathematical model is an adequate tool for computing the forces that should be created on UAV control surfaces while the bench tests. The model accounts for the key factors of the flight environment such as airspeed, altitude, vehicle angular position, and wind disturbances. The obtained results confirm the fundamental possibility of implementing such a system based on a linear electromagnetic actuator. The model may serve as the basis for creating real bench equipment, allowing a significant reliability increase of the UAV control systems ground-based testing, a reduction in the number of the required flight experiments, and, consequently, a reduction in the lead time and cost of the unmanned aerial systems development.
A prospect for further research is this model integration with real hardware, as well as accounting for nonlinear aerodynamic effects and aerodynamic unsteadiness.

Keywords:

UAV control system, UAV ground tests, aerodynamic load simulation system, semi-natural modeling, hinge moment, aileron, electromagnetic loader, UAV spatial position

References

  1.  Lukyanov OE, Zolotov DV, Espinosa Barsenas OU, et al. Determining aerodynamic characteristics of small unmanned aerial vehicles involving flight experiment. Vestnik of Samara University. Aerospace and Mechanical Engineering. 2023;22(3):59-74. (In Russ.). DOI: 10.18287/2541-7533-2023-22-3-59-74
  2.  Mikhailov SА, Makhan’ko AА, Hamzah MAH. Algorithm for determining the aerodynamic performance by the flight test results. Izvestiya vysshikh uchebnykh zavedenii. Aviatsionnaya tekhnika. 2022(1):123-130. (In Russ.).
  3.  Isaev AM, Linets GI, Isaev MA, et al. Software and hardware complex for simulation modeling of a multirotor uav flight. Infokommunikacionnye Tehnologii. 2020;18(2):177-187. (In Russ.). DOI: 10.18469/ikt.2020.18.2.08
  4.  Sukhykh NN, Rukavishnikov VL. Methods and means for conducting semi-natural modeling of aircraft control processes on a special stand. Polet. Obshcherossiiskii nauchno-tekhnicheskii zhurnal. 2022(8-9):26-34. (In Russ.).
  5. Seroshtanov DA, Strelkov VV. Developing the appearance of a versatile bench with aircraft’s dynamics model and control handles. Avtomatizatsiya v promyshlennosti. 2023(5):14-17. (In Russ.). DOI: 10.25728/avtprom.2023.05.03
  6.  Kirillov AV, Sitnikov VV, Tuchin AL. Automation of the process of testing on-board systems of unmanned aerial vehicles. Vestnik of Samara University. Aerospace and Mechanical Engineering. 2024;23(2):14-27. (In Russ.). DOI: 10.18287/2541-7533-2024-23-2-14-27
  7.  Elgohary AA, Ashry AM, Kaoud AM, et al. Hardware-in-the-loop simulation of UAV Altitude Hold Autopilot. AIAA SciTech Forum (January 3-7, 2022; San Diego, CA & Virtual). DOI: 10.2514/6.2022-1520
  8.  Kiselev MA, Ismagilov FR, Sayakhov IF. Electric actuators for aircraft aerofoils control. Aerospace MAI Journal. 2017;24(2):141-148. (In Russ.).
  9.  Al'bokrinova AS, Grumondz VT. Gliding unmanned aerial vehicle flight dynamics at low speed and launch altitudes. Aerospace MAI Journal. 2017;24(2):79-85. (In Russ.).
  10.  Pravidlo MN, Prokudin SV. Assessment of economic effect at mathematical modeling of aerodynamic characteristics. Aerospace MAI Journal. 2015;22(4):32-37. (In Russ.).
  11.  Golovnev AV, Voronko DS, Danilov SM. Studying aerodynamic interference of the unmanned aerial vehicles at the intervals and height variation in team flight. Aerospace MAI Journal. 2023;30(1):36-44. (In Russ.). DOI: 10.34759/vst-2023-1-36-44
  12.  Bogatyrev VV. Numerical investigations of the aerodynamic characteristics for an improved airfoil with a control surface. Uchenye zapiski TsAGI. 2020;51(3):15-24. (In Russ.).
  13.  Astakhov SA, Biryukov VI, Timushev SF, et al. Aerodynamic interaction simulation during track testing of aircraft products. PNRPU Aerospace Engineering Bulletin. 2023(72):5-20. (In Russ.). DOI: 10.15593/2224-9982/2023.72.01
  14.  Pischasov VM, Bardaev PP, Shemyakin AP, et al. The system for measuring hinge moments in the SibNIA T-203 wind tunnel. Materialy IV Otraslevoi konferentsii po izmeritel'noi tekhnike i metrologii dlya issledovanii letatel'nykh apparatov “Kimila 2020“ (November 10-11, 2020; Zhukovskii). Zhukovskii: TsAGI; 2020. p. 286-292. (In Russ.).
  15.  Akimov VN, Gryzin SV, Parafes SG. Studying the “rudder-drive” system with accounting for the rudder flexural-and-torsional vibrations. Aerospace MAI Journal. 2020;27(3):73-83. (In Russ.). DOI: 10.34759/vst-2020-3-73-83
  16.  Usoltsev AA. Electric drive. St. Petersburg: ITMO University; 2012. 238 p. (In Russ.).
  17.      Pakhomov AN, Krivenkov MV, Pakhomov AN, et al. Teoriya elektroprivoda. Krasnoyarsk: IPK SFU; 2009. 146 p. (In Russ.).
  18.      Besekerskii VA, Popov EP. Theory of automatic control systems: linear systems. Nonlinear systems. The impulse. the system. Digital and adaptive. the system. Sustainability criteria. Random processes. 4th ed. St. Petersburg: Professiya; 2004. 747 p. (In Russ.).
  19.  Golubev AG, Kalugin VT, Lutsenko AYu, et al. Aerodynamics. Moscow: BMGTU; 2010. 687 p. (In Russ.).
  20.      Kitaev VN, Kosvintseva NA, Obrezkov AYu, et al. Aerodynamic angle sensor system. Materialy XXX Mezhdunarodnogo simpoziuma “Nadezhnost' i kachestvo” (May 26 – June 01, 2025; Penza). Penza: Penza State University; 2025. Vol. 2. p. 219-221. (In Russ.).
  21.  Korsun ON, Daneko AI, Motlich PA, et al. Attack and Sideslip of Unmanned Aerial Vehicle in the Absence of Aerodynamic Angle Sensors. Mekhatronika, Avtomatizatsiya, Upravlenie. 2022;23(5):274-280. (In Russ.). DOI: 10.17587/mau.22.274-280
  22.  Shevchenko AV, Muravitskaia LA. Computational and experimental studies of aerodynamic characteristics of unmanned aerial vehicles at subsonic speeds. Trudy MAI. 2024(138). (In Russ.). URL: https://trudymai.ru/eng/published.php?ID=182661

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