The Formulation and Solution of the Multi-objective Optimization Problem for an Autonomous Electrohydraulic Servo Actuator with Combined Control

The rapid development of electrical engineering industries for aviation has resulted in a gradual transition to the autonomous electrohydraulic drives, among which an electro-hydrostatic drive is currently considered to be the most advanced. However, high requirements for dynamic parameters of modern unstable and low-stability aircrafts put restriction on implementation of electro-hydrostatic drives in the industry.

A combined control hydraulic drive arisen from the electro-hydrostatic drive development solves the problem of low dynamic parameters. High dynamics for combined control is achieved through the use of double (throttle and electric power) control with each of them being predominant depending on the input signal value.

Due to small knowledge of the drive with combined control, the article proposes to use a multi-criterion optimization method in order to obtain optimal results in its development. This will allows an adequate estimate of drive performance for its comparison with analogues and a justification of the feasibility of further research as well.

The article describes all the stages of multi-criteria optimization of the combined control drive using the LP-search method. Optimization is carried out taking into account the requirements for modern aircrafts. As criteria, were taken three values , which, in the authors' opinion, provide the most complete description of the entire drive quality (a drive power consumption in the "neutral", an efficiency of the hydraulic part of the drive in the mode of electric power control, a value of ITAE when driving with a small signal). As a result of optimization, the Pareto front was obtained in three coordinates, corresponding to effective solutions, after which a compromise between the criteria was found, and the optimal solution was chosen.

The design solution of the combined control drive, obtained after optimization, meets all the requirements for modern aircrafts and has both the high power performance and the high dynamics. Nevertheless, this study should be considered incomplete because of not taking into account a number of parameters, including weight-size and drive reliability ones.

1. Selivanov A.M., Alekseenkov A.S., Naydenov A.V. Prospects of autonomous electrohydraulic drive. Izvestiia Tul’skogo gosudarstvennogo universiteta. Tekhnicheskie nauki [News of the Tula State Univ. Engineering Science], 2011, no. 5-1, pp. 359-364 (in Russian).

2. Adams С. A380: More electric aircraft. Avionics Magazine, 2001, October 1. Available at: http://www.aviationtoday.com/2001/10/01/a380-more-electric-aircraft/, accessed 19.03.2017.

3. Mashinostroenie: entsiklopediia. V 40 t. Razdel IV: Raschet i konstruirovanie mashin. T. IV-2: Elektroprivod. Gidro- i vibroprivody. Kn. 2: Gidro- i vibroprivody [Mechanical engineering: Encyclopedia. In 40 vols. Pt. IV: Calculation and design of machines Vol. 4-2: Electric drive. Hydraulic and vibro drives. Book 2: Hydraulic and vibro drives / D.N. Popov, V.K.Astashev, A.N. Gustomiasov a.o.; ed. by D.N. Popov, V.K. Astashev]. Moscow: Mashinostroenie Publ., 2012. 303 p. (in Russian).

4. Navarro R. Performance of an electro-hydrostatic actuator on the F-18 systems research aircraft. Edwards, CA, USA: NASA, 1997. 33 p.

5. Shumilov I.S. Hydraulic actuators with autonomous hydraulic supply for the mainline aircrafts. Nauka i obrazovanie MGTU im. N.E. Baumana [Science and Education of the Bauman MSTU], 2014, no. 8, pp. 139-161. DOI: 10.7463/0814.0724446 (in Russian)

6. Kang Rongie, Jiao Zongxia, Wang Shaoping, Chen Lisha. Design and simulation of electro-hydrostatic actuator with a built-in power regulator. Chinese J. of Aeronautics, 2009, vol. 22, no. 6, pp. 700-706. DOI: 10.1016/S1000-9361(08)60161-2

7. McCullough K.R. Design and characterization of a dual electro-hydrostatic actuator: doct. diss. Hamilton, Ontario: McMaster Univ. Publ., 2011. 193 p.

8. Selivanov A.M. The principle of combined speed control output unit hydraulic drive and its modern implementation. Vestnik Moskovskogo Aviatsionnogo Instituta [Herald of the Moscow Aviation Institute], 2011, vol. 18, no. 3, pp. 147-151 (in Russian).

9. Khomutov V.S. Uluchshenie staticheskikh i dinamicheskikh kharakteristik elektrogidrostaticheskogo privoda v oblasti malykh signalov upravleniia. Kand diss. [Improvement of static and dynamic characteristics of an electrohydrostatic actuator in the field of small control signals. Cand. diss.]. Moscow, 2008. 178 p. (in Russian).

10. Alekseenkov A.S. Research of characteristics and working processes of autonomous electrohydraulic actuator with combined speed control. Sovremennye problemy nauki i obrazovaniia [Modern Problems of Science and Education], 2014, no. 2, p. 122. Available at: https://www.science-education.ru/ru/article/view?id=12896, accessed 19.03.2017 (in Russian).

11. Selivanov A.M., Alekseenkov A.S., Naydenov A.V. Evaluation field of throttle control in the drive with combined control of output link. Izvestiia Tul’skogo gosudarstvennogo universiteta. Tekhnicheskie nauki [News of the Tula State Univ. Engineering Science], 2011, no. 5-1, pp. 299-303 (in Russian).

12. Nozhnin O.S. Combined regulation electro-hydraulic actuator. Molodezhnyj nauchno-tekhnicheskiji vestnik. MGTU im. N.E. Baumana [Youth Scientific and Technical Bulletin of the Bauman MSTU], 2016, no. 5. Available at: http://sntbul.bmstu.ru/doc/839489.html, accessed 19.03.2017 (in Russian).

13. Alekseenkov A.S. Uluchshenie dinamicheskikh svojstv i issledovanie rabochikh protsessov aviatsionnogo rulevogo gidroprivoda s kombinirovannym regulirovaniem skorosti pri uvelichenii vneshnei nagruzki. Kand diss. [Improvement of dynamic and static characteristics and research of working processes of the aircraft hydraulic steering acruator with combined speed control with increasing external load. Cand. diss.]. Moscow, 2014. 150 p. (in Russian).

14. Popov D.N. Efficiency evaluation and optimal designing of hydraulic drives. Vestnik mashinostroeniia [J. of Mechanical Engineering], 1986, no. 9, pp. 20-23 (in Russian).

15. Borovin G.K., Popov D.N. Mnogokriterial’naia optimizatsiia gidrosistem [Multi-criteria optimization of hydraulic systems]: a textbook. Moscow: Bauman MSTU Publ., 2007. 94 p. (in Russian).

16. Zamaraev D.S., Popov D.N. Optimization of an electrohydraulic actuator for a servo drive with throttle control. Nauka i obrazovanie MGTU im. N.E. Baumana [Science and Education of the Bauman MSTU], 2013, no. 12, pp. 105-123. DOI: 10.7463/1213.0637872 (in Russian)

17. Sobol’ I.M., Statnikov R.B. Vybor optimal’nykh parametrov v zadachakh so mnogimi kriteriiami [Choice of the optimal parameters in problems with many criteria]. 2nd ed. Moscow: Drofa Publ., 2006. 175 p. (in Russian).

18. Karpenko A.P. Sovremennye algoritmy poiskovoj optimizatsii. Algoritmy vdokhnovlennye prirodoj [Modern methods of search optimization]. Moscow: Bauman MSTU Publ., 2014. 446 p. (in Russian).

19.