Fuzzy logic-based flexible wing aircraft roll and structural torsion moment control

A fuzzy-logic-based, multi-input/output roll controller that has been designed for Rockwell International´s Advanced Technology Wing (ATW) aircraft to control roll rate and torsion loads is described. The ATW integrates active controls with a flexible wing structure to provide wing shapes that optimize particular flight performance criteria. Because of the large variations in the dynamic model of the ATW as a function of flight condition, a fuzzy controller has been used for roll rate and load alleviation control. Fuzzy rules have been developed to determine the appropriate wing deflections on the basis of roll rate error and roll acceleration. The fuzzy controller modulates the control surfaces to achieve a commanded roll rate while ensuring that the torsion moments are within acceptable bounds. The use of fuzzy-logic-based control is motivated by its ability to capture qualitative control strategies and implement highly flexible control behavior. Simulation results show the fuzzy controller provides excellent roll performance without exceeding load constraints