Design of Fuzzy Control System for Generic Aircraft/UAVs

Abstract

This paper provides an approach for design of Fuzzy Model Based (FMB) control system for generic aircraft and UAV related application. The FMB control is an evolving nonlinear control strategy which consists of a fuzzy model and a fuzzy controller connected in a closed-loop. In proposed work an application-oriented research, in which an emerging soft computing-based technique (fuzzy system) is applied for design of flight control system of Generic aircraft. The existing theoretical base developed in fuzzy systems literature is explored/customized for aircraft related application. The short period mode of longitudinal aircraft dynamics is considered for simulation and demonstration purpose. The fuzzy model of longitudinal aircraft dynamics are obtained from nonlinear dynamics equations about various representative points (equilibrium points) of flight envelop with some fuzzy rules. The aircraft flight envelope parameters i.e operating altitude and Mach Number are characterized as premise parameters and elements of stability and control derivative matrix are identified as consequent parameters of fuzzy model. The decay rate fuzzy controller with constraint on state and control input parameters is considered and its feedback gains are obtained by solving the LMI stability conditions. The closed-loop response of FMB controller is presented at three initial flight conditions. The simulation result reveals that proposed FMB controller is well suited at various identified operating points of the flight envelop. It not only stabilizes the aircraft dynamics but also provides improved transient performance. This demonstrates the utility of FMB control system for aircraft / UAVs related application.