Modeling and Mode Switching Analysis of Electro‑hydrostatic Actuators for Primary Flight Control System

With the advancement of more electric aircraft（MEA）technology，the application of electro-hydrostatic actuators（EHAs）in aircraft actuation systems has become increasingly prevalent. This paper focuses on the modeling and mode switching analysis of EHA used in the primary flight control actuation systems of large aircraft，addressing the challenges associated with mode switching. First， we analyze the functional architecture and operational characteristics of multi-mode EHA，and sumarize the operating modes and implementation methods. Based on the EHA system architecture，we then develop a theoretical mathematical model and a simulation model. Using the simulation model，we analyze the performance of the EHA during normal operation. Finally，the performance of the EHA during mode switching under various functional switching scenarios is investigated. The results indicate that the EHA meets the performance requirements in terms of accuracy，bandwidth，and load capacity. Additionally，the hydraulic cylinder operates smoothly during the EHA mode switching，and the response time for switching between different modes is less than the specified threshold. These findings validate the system performance of multi-mode EHA，which helps to improve the reliability of EHA and the safety of aircraft flight control systems.