This paper presents intelligent particle swarm optimization (PSO) based adaptive neuro fuzzy inference system (ANFIS) (Sugeno type) as a new approach to the problem of aerodynamic modeling and parameter estimation for both aerodynamically stable and unstable aircraft in presence of measurement error (sensor noise). A PSO optimizer based neuro fuzzy system capable of predicting generalized force and moment coefficients employing measured motion and control variables only, without the requirement of conventional variables or their time derivatives, have been proposed. Furthermore, it is shown that such a model can be used to extract equivalent stability and control derivatives using both linear and nonlinear kinematic models of a rigid aircraft in presence of uncertainties in the form of instrument or measurement error. Simulated data of an unstable test aircraft, derived from a nonlinear six DOF. simulation, have been utilized to illustrate efficacy of the method. Results have been depicted to highlight the usefulness of the proposed algorithm.
Nomenclature, D L C C = Drag and lift coefficients , , l m n C C C = Coefficient of rolling, pitching and yawing moment 0 0 0 , , D L y C C C = pressure coefficient 0 0 0 , , l m n C C C = pressure coefficient C N = Normal force coefficient R = Measurement noise covariance matrix u,v,w = Longitudinal, Lateral, and vertical airspeed components = Vector of unknown parameters V = Velocity vector Y(k) = Estimated response e = Elevator deflection = Angle of attack J = Cost function , , = Angles of roll, pitch and yaw a,b,c = Arbitrary coefficients i j O = Output of j th neuron of i th layer sf = Spread factor s = Spread = Deviation