Synthesis of An Integrated Fuzzy/Nonlinear Controller For Rotorcraft

In this paper, synthesis of a helicopter full authority flight controller using an integrated (fuzzy) rule based and (nonlinear) model based control approach is presented. First, fuzzy rules, based on qualitative analysis of helicopter response characteristics, are developed for converting velocity commands and accelerations in the horizontal plane into required pitch and roll attitudes of the vehicle. Then, a model-based nonlinear controller previously developed for control of body attitudes is combined with the rule-based fuzzy controller to arrive at an integrated fuzzy/nonlinear control approach. Its performance and robustness are evaluated through simulation of typical command maneuvers. Also, preliminary results obtained using a genetic algorithm for choosing membership functions for the fuzzy controller are included.