Designing a Multi-Level Controller in Aircraft Pitch Angle

Progress in aircraft designs heavily depend on Automatic Flight Control System (AFCS). In this work a fuzzy sliding mode controller is designed as a supervisory controller in aircraft pitch control systems and different control strategies to model a pitch controller based on design a pitch angle control in autopilot are invistigated. A performance evaluation based on time response specification between modern control Linear Quadratic Regulator (LQR) and multi-level intelligent controller (based on Fuzzy Logic Controller, FLC and Supervisory FLC, SFLC) for a pitch control system is presented. The performances of pitch control systems are analyzed based on common criteria of step’s response in order to identify which control strategy delivers better performance with respect to the desired pitch angle. In this work, new approach, SFLC is presented to improve the performance of pure FLC in term of rising time and settling time. It is found that, LQR controller give the better performance compared to pure FLC, and SFLC gives the best performance.