An Analysis of a Digital Electro Hydrostatic Actuator for Application in Aircraft Flight Control Systems

Abstract With the global awareness of reducing greenhouse gas emissions, research into developing more energy efficient hydraulic systems has become important. The aeronautical industry has been looking for more efficient solutions for aircraft application, where the search for more efficient systems has increased considerably, bringing the concept called More Electric Aircraft. However, hydraulic actuators are unbeatable against other technologies, due to their high power/weight ratio and reliability, being the predominant technology in flight control surfaces. Nevertheless, the hydraulic systems have low energy efficiency. With the aim of improving the energy efficiency of hydraulic systems, digital hydraulics has become one of the main technologies under study. However, the use in aircraft is still new. Therefore, this paper presents a digital hydraulic actuator for aircraft flight control surfaces called Digital Electro Hydrostatic Actuator - DEHA. A mathematical model was elaborated and was validated in a test bench rig. The actuator was applied to control an aircraft in the Aero-Data Model in a Research Environment - ADMIRE model. Furthermore, a Servo Hydraulic Actuator - SHA model was developed for comparison. The results show that DEHA can fly the ADMIRE aircraft in the proposed missions, with an energy efficiency of 41.63% while the SHA reached an efficiency of 0.46%, considering the LOE. This represents an efficiency increasing of 90.5 times, which demonstrates that DEHA can be a promising solution for aeronautical application.