Multiple Fuzzy Reference Model Adaptive Controller Design for Pitch-Rate Tracking

A multiple fuzzy reference model adaptive controller (MFRMAC) is proposed for nonlinear aircraft pitch-rate tracking. The controller is developed using a direct model reference adaptive control (MRAC) scheme with variable fuzzy logic reference model. The proposed controller provides a soft reference model switching for the multiple modes of operation of the aircraft without any prohibitive computation or explicit system identification. The effectiveness of the technique is assessed by simulation studies based on a 6-DOF high-performance fighter aircraft model undergoing pitch-rate control at a wide range of operating contingencies. It is demonstrated that the scheme performs extremely well when controlling multimodal dynamic systems, as opposed to conventional MRAC designs.