Pitch Control of an Aircraft Using Artificial Intelligence

This paper presents the investigation into the design, simulation and analysis of two autopilots: a fuzzy Proportional-Integral-Derivative (PID) controller and, its hybrid with a PID controller for the control of pitch plane dynamics of an aircraft. The Mamdani-type fuzzy inference system is employed for the Fuzzy Inference System (FIS) in the fuzzy logic controller design. The dynamic modeling of system begins with a derivation of suitable mathematical model to describe the longitudinal motion of an aircraft. This research set the platform for thorough investigation into the various structures available for PID-FLC and its hybrids. Considering hardware implementation challenges and limitations, not all PID-FLC and its hybrid structures are viable. The PID-FLC is constructed as a parallel structure of a PD-FLC and a PI-FLC, with the output signal of the control loop, y serving as the input for the derivative parameter of the PD-FLC. The output of the PID-FLC is formed by algebraically adding the outputs of the two fuzzy control blocks as suggested in Guanrong et al., 2000. Also, the proposed hybrid fuzzy PID autopilot consists of the PID-FLC with a traditional PID controller structured by algebraically adding the outputs of the two control blocks. Result of simulation in MATLAB®/Simulink® shows that the proposed PID-FLC autopilot gave an unacceptable trend when subjected to a step response and Dirac’s delta impulse response investigation. While the intelligent hybrid autopilot; PID-FLC with PID controller gave an acceptable time response characteristics.