Electric actuators for aircraft aerofoils control

Аuthors

Kiselev M. A.^1*, Ismagilov F. R.², Sayakhov I. F.^2**

1. State Institute of Aviation Systems, 7, Victorenko str., Moscow, 125319, Russia
2. Ufa State Aviation Technical University, USATU, 12, K. Marx str., Ufa, 450008, Republic of Bashkortostan, Russia

*e-mail: makiselev@2100.gosniias.ru
**e-mail: isayakhov92@mail.ru

Abstract

While increasing the aircraft degree of electrification hydraulic drives fed by centralized fluid power systems substitution by off-line electric drives is assumed.

Translational motion power actuators with ball-and-screw gear are widely used nowadays in aircraft flaps, slats and adjustable stabilizers control systems, and operate reliably for a few minutes per flight.

In the absence of strict requirements to the dynamic characteristics of electric actuators, such as high-lift drives, simple electromechanical actuators with controllable electric motors and mechanical gear are already in use.

During the flight of an aircraft, controlled airfoils are exposed to varying loads under the influence of airflows. These loads cause significant mechanical stresses in the electromechanical actuator, leading to accelerated wear of mechanical actuator components. Another problem with the existing electric actuators is their excessive weight and size as well as difficulty to ensure compliance with the stringent operational safety requirements.

Thus, the goal of this research consists in eliminating these deficiencies and improving the energy and operating characteristics of electric actuators. It is necessary herewith to consider the operation of an electric drive either in active mode, when the energy is spent to set the running gear in motion, or in passive mode, when the running gear is fixed in a certain position and exposed to significant mechanical loads caused by aerodynamic forces.

Based on the presented aerodynamic forces calculations, we analyze the designs that solve the stated problems. These designs allow implementing both the passive and the active electric actuator modes.

We propose a design that makes electric actuators more reliable and durable while operating in the passive mode. This is achieved by removing the output arm from the deadlock position to allow a limited range of deflection and by damping vibrations and oscillations caused by aerodynamic forces within that range.

However, oscillations damping by electromechanical dampers is not always efficient, since it may result in weight and size figures increase under high mechanical loads. This problem could be solved by implementing the electric actuator structure with flexible coupling between the ball-and-screw gear and remaining actuator components in the form of modified elastic compensating clutch. This proposed flexible coupling demonstrates small weight and size figures compared to with electromechanical dampers under heavy loads. Thus, such structure can be realized also in spacecraft.

Judging from the above said, the considered electric actuator construction arrangement allows reduce its weight and size figures. The resource increase in electric actuator passive operation mode is achieved by eliminating rigid fixation of the output arm in dead spots and limited oscillations of the output arm in the operating range of a position sensor.

Keywords:

electric actuator construction arrangement, aerodynamic loads, passive operation mode

References

1. Final programme including short abstracts and proceedings. 25th Congress of the International Council of the Aeronautical Sciences “ICAS 2006”. Hamburg, Germany, 3 – 8 September, 2006, 76 p., available at: http://www.icas2006.org/ICAS2006_FinalProgramme.pdf

2. Gruzkov S.A., Ostanin S.Yu., Sugrobov A.M., Tokarev A.B., Tyrichev P.A. Elektrooborudovanie letatel'nykh apparatov (Electric flying vehicles), Moscow, MEI, 2005, vol. 1, 564 p.

3. Stephen C. Jensen, Gavin D. Jenney, Bruce Raymond, David Dawson. Flight Test Experience With an Electromechanical Actuator on the F-18 Systems Research Aircraft. 19^th Digital Avionics Systems Conference, October 713, 2000, Philadelphia, Pennsylvania, 10 p.

4. Bachurin P.A., Korobkov D.V., Kharitonov S.A., Khlebnikov A.S. Silovaya elektronika i elektroenergetika, 2014, vol. 1, no. 9 (128), pp. 68-75.

5. Ermakov S.A., Karev V.I., Mitrichenko A.N., Selivanov A.M., Sukhorukov R.V. Vestnik Moskovskogo aviatsionnogo instituta, vol. 17, no. 3, pp. 18-29.

6. Bekhtir V.P., Rzhevskii V.M., Tsipenko V.G. Prakticheskaya aerodinamika samoleta Tu-154M (Practical aerodynamics of Tu-154M), Moscow, Vozdushnyi transport, 1997, 286 p.

7. Andryukhin V.A., Efimov V.V., Bekhtina N.B. Konstruktsiya i prochnost' letatel'nykh apparatov (The design and strength of aircraft), Moscow, MGTU GA, 2003, 68 p.

8. Claeyssen F., Janker P., LeLetty R., Sosniki O., Pages A., Magnac G., Christmann M., Dodds G. New Actuators for Aircraft, Space and Military Applications. ACTUATOR 2010, 12^th International Conference on New Actuators, Bremen, Germany, 1416 June 2010, pp. 324-330.

9. Syromyatnikov V.S. Stykovochnye ustroistva kosmicheskikh apparatov (Docking device spacecraft), Moscow, Mashinostroenie, 1984, 216 p.

10. Kulaev V.E., Orlyanskii A.V., Yakovleva L.I., Kalugin D.S., Likhanos V.A., Galkov V.Yu., Kulaev E.V. Mufty mekhanicheskie dlya soedineniya valov, konstruktsiya i osnovnye printsipy proverochnykh raschetov na prochnost' (Mechanical couplings for shaft connection, design and basic principles of checking strength calculations), Stavropol, Stavropol'skii gosudarstvennyi agrarnyi universitet, 2014, 46 p.