Experimental Verification of System Identification
KAMAN AEROSPACE CORP BLOOMFIELD CT
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Laboratory testing of helicopter system identification by single- point excitation showed correlation among the parameters identified by free-body shaking at two different points and theoretically derived parameters of the test specimen. Among the parameters investigated were the mass and stiffness matrices of five- and six-degree-of-freedom models and the structural damping coefficient of a continuous specimen. Experimentation demonstrated the identification of mathematical models having more degrees of freedom than modes in the measurements, a method of obtaining modal parameters by antiresonance theory, an engineering solution to the problem of imaginary antiresonance in Biots Equation and Duncans Equation for transfer impedances, a method of obtaining static influence coefficients by free-body testing without assumption of a mass matrix, and a method of determining static structural test loads of helicopter maneuvers.