Abstract
The aircraft hydraulic system is very important for the actuation system and its failure has led to a number of catastrophic accidents in the past few years. The reasons for hydraulic loss can be leakage, blockage, and structural damage. Fortunately, the development of more electric aircraft (MEA) provides a new means of solving this difficult problem. This paper designs an active fault tolerant control (AFTC) method for MEA suffering from total hydraulic loss and actuation system failure. Two different kinds of scenarios are considered: leakage/blockage and vertical tail damage. With the application of the dissimilar redundant actuation system (DRAS) in MEA, a switching mechanism can be used to change the hydraulic actuation (HA) system into an electro-hydrostatic actuation (EHA) system when the whole hydraulic system fails. Taking account of the gap between HA and EHA, a degraded model is built. As for vertical tail damage, engine differential thrust control is adopted to help regain lateral-directional stability. The engine thrust dynamics are modeled and the mapping relationship between engine differential thrust and rudder deflection is formulated. Moreover, model reference control (MRC) and linear quadratic regulator (LQR) are used to design the AFTC method. Comparative simulation with the NASA generic transportation model (GTM) is carried out to prove the proposed strategy.
Highlights
Safety and reliability are increasingly important requirements in modern transportation systems, especially for civil aircrafts
When the MEA suffers from this, the longitudinal control of the aircraft can be ensured when failure happens, because the elevators of the more electric aircraft are all adopted by dissimilar redundant actuation system (DRAS) based on the hydraulic actuator and electro-hydrostatic actuator (HA/electro-hydrostatic actuation (EHA))
Throughout this paper, nominal and damaged lateral-directional MEA models were built, and an active fault tolerant control (AFTC) strategy based on the model reference control (MRC) algorithm combined with linear quadratic regulator (LQR) regulator was proposed for two scenarios of MEA suffering from total hydraulic loss
Summary
Safety and reliability are increasingly important requirements in modern transportation systems, especially for civil aircrafts. With abundant redundancies in modern civil aircraft, fault-tolerant control strategies have been widely developed [1], which are important to ensure the aircraft’s recovery from severe failure and improve its reliability As for control strategies, many AFTC approaches to combating actuator failure and structural damage can be found, such as linear parameter varying (LPV) [14,15], multi-model (MM) [16], adaptive control [17,18,19,20,21,22], model following [23,24], neural networks [25,26,27], and model predictive control (MPC) [28], etc Researchers such as Hitachi and Liu [29], James M et al [30], and Lu [31]. The simulation proved the performance of the designed AFTC strategy when the hydraulic system fails
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
