Model-Less Fuzzy Logic Control for the NASA Modeling and Control for Agile Aircraft Development Program

The NASA Modeling and Control for Agile Aircraft Development (MCAAD) program seeks to develop new ways to control unknown aircraft to make the aircraft development cycle more efficient. More specifically, there is a desire to control an aircraft with an unknown mathematical model using only first principles of flight. In other words, rather than using a rigorously developed mathematical model combined with wind-tunnel tests, a controller is sought which would allow one to bypass the development of a rigorous mathematical model and enter wind-tunnel testing more directly. This paper presents the design of a fuzzy PID controller, governed by a fuzzy supervisory system which incorporates knowledge of first principles of flight, to control a model-less aircraft\u27s pitch dynamics in a free-to-pitch wind-tunnel environment. This hybrid structure is implemented using a PID controller constructed from independent fuzzy inference systems and augmented in real time by a supervisory system also constructed of independent fuzzy inference systems. Experimental results of the pitch control performance and real-time adaptivity capabilities are presented for both aerodynamically stable and unstable aircraft models