SIZING AND STUDY OF THE REGULATION SYSTEM OF A MECHANICAL ACTUATOR FOR SECONDARY FLIGHT CONTROLS IN A REGIONAL TRANSPORT AIRCRAFT

In recent decades, the continuous evolution of flight control technologies has sparked a growing interest in implementing more electric systems within modern aircraft. This thesis aims to address the issue of electromechanical actuation for secondary flight controls, with the goal of facilitating the transition towards a more electric aircraft configuration. To provide a comprehensive understanding of the research area, the thesis begins by presenting a general context on flight control design and the ongoing developments in this field. The increasing demand for enhanced performance, efficiency, and reliability has driven the exploration of more electric aircraft concepts. Within this context, the utilization of electromechanical actuators has emerged as a promising avenue for achieving the desired objectives. The thesis then focuses on examining the applicability and performance characteristics of electromechanical actuators. The research work presented in this thesis was developed in cooperation with Leonardo Labs, with the final purpose of producing a digital twin for a possible Electro-Mechanical actuation system of a fowler flap for a future regional transport aircraft. In the specific case studied, the flight control surface considered is a fowler flap. The chosen architecture for the electromechanical actuation system involves the implementation of two parallel actuators. This redundant configuration enhances safety and provides fault tolerance, ensuring continued control functionality even in the event of a single actuator failure. By taking into account factors a preliminary sizing process is carried out. This process involves evaluating the actuator's ability to meet the required load and displacement demands under different operating conditions. To gain further insights into the system's behaviour, extensive analyses are conducted under diverse operational scenarios. The effects of temperature variations on the actuator's performance are examined, along with the implications of a fault occurring in one of the parallel actuators. Additionally, considerations are made for the system's startup and shutdown conditions to guarantee its safety and reliability. In designing the control system, the focus is on determining appropriate gain values for the various control loops in the linear regime. By considering stability requirements and performance objectives, approximate gain values are identified. Furthermore, stability margins are quantified to ensure a robust and stable control system. To analyse the system's behaviour in a more realistic and complex environment, a high-fidelity model is developed using the Matlab-Simulink® simulation platform. This model incorporates equations available in the literature and enables an in-depth analysis of the system's response in nonlinear regimes. By leveraging this model, the dynamic behaviour of the electromechanical actuation system is evaluated across its entire operating range. In conclusion, this thesis provides a comprehensive analysis of the electromechanical actuation for secondary flight controls in the context of more electric aircraft. By addressing key aspects such as system architecture, dimensioning, behaviour analysis, control system design, and validation, valuable insights are gained. The results obtained contribute to the ongoing efforts in designing more efficient, reliable, and sustainable flight control systems for future aircraft.