Review on electro hydrostatic actuator for flight control

Electro Hydrostatic Actuator (EHA) is an emerging aerospace technology that aims at replacing centralised hydraulic system by a self-contained and localised direct drive actuator system. EHA has become an important part of modern flight control systems due to the increased efficiency, reduced leakages and lower overall weight compared to conventional hydraulic systems. This paper reviews literature (in English language only) published in the period 1990 to 2015 and available at major technical university libraries or e-journals. It examines the advantages, limitations and possible configurations of the EHA. The paper also includes control strategies, reliability and fault tolerant techniques along with the thermal aspects of the EHA system. EHA is a multi-domain system consisting of electrical, mechanical, hydraulic and control system. It is treated as a mechatronic system and review of publications related to multi-disciplinary modelling/simulation approaches have been presented in the paper. The various issues in design optimisation of EHA for flight application are elaborated. The review concludes by summarising the scope for further research in the area of redundancy strategies and approaches for integrated vehicle health management.