Control law for the automatic docking procedure during aerial refueling

Control systems


Obolensky Y. G.*, Pohvalensky V. L., Cheglakov D. I.**

MIG corporation, 6, Leningraskoe shosse, Moscow, 125171, Russia



Automatic in-flight refueling of unmanned aerial vehicle (UAV).
This paper addresses the fly-by-wire system automatic control algorithm design for the in-flight refueling procedure of high maneuverable aircraft.
The main goal is to navigate and control UAV (during the docking phase of in-flight refueling procedure) so that probe will link up with the drogue mounted on the flexible hose trailing behind the aircraft-tanker. Practical probe and drogue autonomous in-flight refueling requires a robust relative navigation and control algorithm to be designed.
The design process of the control algorithm can be divided into three main parts. The first one includes linearization of UAV equations of motion for the typical values of airspeed and altitude when in-flight refueling. This can be carried out by commonly used linearization technique. The second part consists of linear analysis and design of the inner loop (angular velocity stabilization) control algorithm. The design process is based on the L1 adaptive control theory. In the third part, the linear observers and other components of outer control loop are developed. Feasibility and performance of the total system were demonstrated by simulation of unmanned refueling aircraft docking maneuvers with the non-stationary drogue of an unmanned tanker.
Results presented in the paper showed that the controller can enable precise in-flight refueling thanks to the new algorithm, allowing for real measurement errors, plant modeling errors, and disturbance.
Presented in this paper control algorithm may be used in a fly-by-wire systems of modern manned and unmanned aerial vehicles.


fly-by-wire system, aerial refueling, docking procedure, wake vortex, observer


  1. Mao W., Eke F.O. A survey of the dynamics and control of aircraft during aerial refueling, Nonlinear Dynamics and System Theory, 2008, no. 8, pp. 375-388.
  2. Cheglakov D.I. Al'manakh Novyi Universitet (tekhnicheskie nauki), 2011, no. 4, pp. 34-47.
  3. Smith R.K. Seventy-Five Years of Inflight Refueling, Highlights, 1923–1998, U.S. Government Printing Office, Washington, D.C., 1998, 90 p.
  4. Bjushgens G.S., Studnev R.V. Dinamika prodol'nogo i bokovogo dvizheniya (Longitudinal and lateral airvehicle dynamics), Moscow, Mashinostroenie, 1978, 350 p.
  5. Saban D., Whidborn J. F., Cooke A.K., Simulation of wake vortex effects for UAVs in close formation flight, The Aeronautical Journal, 2009, vol. 113, no. 1149, pp. 727-738.
  6. Dogan A., Lewis T., W. Blake, Flight Data Analysis and Simulation of Wind Effects During Aerial Refueling, Journal of Aircraft, 2008, vol. 4, no. 6, pp. 2036-2048
  7. Ro K., Kamman W. Modeling and Simulation of Hose-Paradrogue Aerial Refueling Systems, Journal of guidance, control and dynamics, 2010, vol. 33, No. 1, pp. 53-63.
  8. Jaroshevskij V. A. Uchenye zapiski CAGI, 2003, vol. 34, no. 3-4, pp. 91-108.
  9. Mammarella M., Campa G. Machine vision/GPS integration Using EKF for the UAV aerial refueling problem, IEEE Transactions on system, man and cybernetics, part C, 2008, vol. 38, no. 6, pp. 791-801.
  10. Hovakimyan N. Cao C. L1 Adaptive control theory: Guaranteed Robustness with fast adaptation, Society for Industrial and Applied Mathematics, Philadelphia, 2010, 320 p.
  11. Kuzovkov N. T. Modal'noe upravlenie i nablyudayushchie ustroistva (Modal control and state observers), Moscow, Mashinostroenie, 1976, 184 p.
  12. Tandale, M.D., Bowers, R., and Valasek, J. Robust Trajectory Tracking Controller for Vision Based Probe and Drogue Autonomous Aerial Refueling. AIAA Guidance, Navigation, and Control Conference and Exhibit, 15–18 August 2005, San Francisco, California, USA, AIAA 5857–5868.
  13. M. D. Tandale, R. Bowers, and J. Valasek Trajectory Tracking Controller for Vision-Based Probe and Drogue Autonomous Aerial Refueling, Journal of Guidance, Control, and Dynamics, 2006, vol. 29, no. 4, pp 846-857.
  14. Poedinok V.M. Uchenye zapiski CAGI, 2005, vol. 36, no. 1-2, pp. 95-102.

Download — informational site MAI

Copyright © 2000-2024 by MAI