TWO NEW METHODS FOR OBTAINING STABILITY DERIVATIVES FROM FLIGHT TEST DATA

摘要

Two new methods for obtaining control and stability derivatives from observed flight data are developed. The first method is based on a quasil1nearization procedure and is applicable in parameter identification problems where the plant is modeled by a system of linear differential equations, and noisy measurements of state and control variables are available. Computationally, this method is equivalent to a modification of the Newton-Raphson method. The second, a "directed random search" method is based on a concept called evolutionary programming, and is also applicable for nonlinear problems. Using X-15 flight test data, the two methods are compared and stability and control derivatives for the lateral motion of the X-15 are given.