Aircraft Parameter Estimation Experiment Design Considering Measurement Colored Residuals

Abstract

This work deals with the optimization of flight-test maneuvers for aerodynamic parameter estimation considering that the measurements are contaminated with colored residuals. The colored residuals consideration is important to give a direct and realistic assessment of the parameter estimation uncertainty levels before flight testing. The design technique is based on the optimization of the flight-test data information content and the Cramer-Rao lower bound. The discrete autocorrelation matrix of the measurement residuals is also used to compose the optimization criterion, thereby explicitly considering colored residuals. To validate the proposed technique, a flight-test campaign of the CEA-205 CB-9 Curumim was performed and its results discussed. The advantages of the proposed maneuver optimization technique are presented, stressing the ease of implementation of the signals and the strong improvement in the estimation procedures made possible with the application of the optimized maneuver signals. Nomenclature a z = vertical acceleration, g Cov() = covariance operator D = dispersion matrix Efg = mathematical expectation operator g = acceleration of gravity, m=s 2 J = cost function operator M = Fisher's information matrix N = vector length p† = probability density function operator q = pitch rate, rad=s R = measurement noise covariance matrix S = output sensitivity matrix with respect to system parameters t = time tr() = matrix trace operator u = input vector V tas = true airspeed, m=s = measurement noise vector x = state vector y = output vector = angle of attack, rad e = elevator deflection, rad = system parameter vector Subscript m = measurement variable Superscripts T = transpose 1 = matrix inversion = parameter estimate error

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