MODELING AND ANALYSIS OF A DIGITAL HYDRAULIC ACTUATOR FOR FLIGHT CONTROL SURFACES

This paper presents the design and modeling process of a flight control actuator using digital hydraulics and a performance analysis that compares the proposed solution and the Servo Hydraulic Actuator (SHA) on a fighter aircraft model. The proposed solution is named Digital Hydraulic Actuator (DHA) and comprises the use of a multi-chamber cylinder controlled by on/off valves and different pressures sources provided by a centralized hydraulic power unit, as proposed in the Fly-by-Wire (FbW) concept. The analyses were carried out using the Aero-Data Model in a Research Environment (ADMIRE), which was developed for flight performance analysis. The actuators were modeled using the software Matlab/Simulink (R) and Hopsan. They were applied to control the aircraft elevons in a flight mission close to the aircraft limits, to evaluate the actuator's behavior and energy efficiency. The results show a reduction in energy dissipation up to 22.3 times when comparing the DHA with the SHA, and despite the overshooting and oscillations presented, the aircraft flight stability was not affected.