Power-by-wire flight control actuators development prospects and issues

Аuthors

Konstantinov G. S.^1*, Kuvshinov V. M.^2**, Kuznetsov I. P.^3***, Parshin A. A.³, Redko P. G.^3***, Steblinkin A. I.^2****, Khaletsky L. V.^2*****

1. RIOLIS, 19, Chekhova str., Pushkino, Moscow region, 141230, Russia
2. Central Aerohydrodynamic Institute named after N.E. Zhukovsky (TsAGI), 1, Zhukovsky str., Zhukovsky, Moscow Region, 140180, Russia
3. Pavlovsky Mashinostroitelny Zavod «Voskhod», PMZ «Voskhod», 78a, Kommunisticheskaya str., Pavlovo, Nizhny Novgorod Region, 606100, Russia

*e-mail: GSKonstantinov@gmail.com
**e-mail: vmkouvsh@progtech.ru
***e-mail: voshod@sinn.ru
****e-mail: Anton.Steblinkin@tsagi.ru
*****e-mail: tsagi_s19@mail.ru

Abstract

Object and purpose of the study

Object of the study is flight control actuation systems (FCAS) for next-generation aircrafts based on energy-saving technologies that are potentially able to provide flight quality and safety ratings significant increase as well as aircraft operation and exploitation overall cost savings and its ecological environment improvement. Electro-mechanical (EMA) and electro-hydrostatic (EHA) actuation are well known among these technologies. Meanwhile the use of such technologies on modern aircrafts is limited despite of their profits.
Electrical actuation technology implementation in modern FCAS influence on overall aircraft safety is the purposes of the study.

Methodology

The common requirements to the traditional electrohydraulic actuator characteristics were used to confront them with characteristics achievable with the present electric actuation technologies (EMA and EHA of different types). These technologies were observed with regard to its safety ratings and dynamic characteristics especially at low input signals (Uin<0,2%Umax).
New type of EHA with combined control of rod velocity was developed by specialists of Voskhod, Moscow aviation institute, Sukhoi and TsAGI. Developed EHA was tested on special testbench for actuators external loading in TsAGI.
Mathematical modelling of closed control loop «Aircraft — Flight control system - Electric actuator» was done to examine developed EHA for primary flight surface deflecting in comparison with traditional electrohydraulic actuator and traditional EHA (motor control). The modelling process was done in MATLAB/Simulink software both for maneuverable and non-maneuverable aircrafts with applying wing disturbances of different velocity (W<4 m/s and W>4 m/s) obtaining aircraft stability margins and flight qualities.

Findings

EMA can only be used at present time in FCAS for deflecting secondary flight surfaces (spoilers, air brakes, interceptors) which failure will not cause the catastrophic situation because of its unproven safety ratings. At the same time, implementing of EHA in FCAS for deflecting primary flight surfaces looks more attractive but is still limited mainly because of its poor dynamic characteristics at low input signals which causes stability margins decrease: 15° of phase margins decrease and 2,5 dB of amplitude margin decrease.

Originality/value

Developed EHA with combined control of rod velocity is original technical solution, which combines high energy efficiency of traditional EHA and good control qualities at low input signals of traditional electrohydraulic actuators and thus can be potentially suitable for primary flight control deflecting.

Keywords:

electrohydraulic actuator with throttle control, electrohydrostatic actuator (EHA), electrohydrostatic actuator (EHA), electrohydrostatic actuator with combined throttle-volume control, electromechanical actuator (EMA), brushless direct current (BLDS) motor, mechatronic unit, flight control system (FCS), stability, controllability

References

1. Sostoyanie i rezultaty nauchno-issledovatelskikh i opytno-konstruktorskikh rabot po sozdaniyu perspektivnykh samoletov elektrogidrostaticheskikh privodov dlya sistem upravleniya poletom AIRBUS (Condition and results of research and developmental works on creation of perspective planes of electrohydrostatic drives for control systems of flight), Мoscow, NIISU, release 1, 2003, 56 p.
2. Konstantinov S.V., Redko P.G., Selivanov A.M., Ermakov S.A., Kuvshinov V.M. Obshcherossiiskii nauchno-tekhnicheskii zhurnal «Polet», 2008, no. 1, pp. 50-60.
3. Konstantinov S.V., Kuznetsov V.E., Polyakov N.D., Redko P.G., Trifonova O.I. Elektrogidravlicheskie rulevye privody s adaptivnym upravleniem manevrennykh samoletov (Electrohydraulic steering transmissions with adaptive control of maneuverable aircraft), St.-Petersburg, LETI, 2011, 511 p.
4. Redko P.G., Konstantinov S.V., Selivanov A.M. Patent RU 2305210, 27.08.2007.