Parameters Identification of a Rotor on Lubricated Journal Bearings

The idea of system identification is to recover the system properties through investigations of ex-perimental data records. The choice of appropriate methods for system identification depends on both types of experimental records and the objectives of the identification. There are various identification tools well documented in literature concerning linear and non-linear systems. The last item is very important because the presence of non-linearity essentially complicates the identification problem since the linear superposition principle becomes inapplicable. In this paper we propose a direct method for the identification of the parameters for one general class of non-linear systems. The only requirement is that the system must be modeled by analytic or sufficiently smooth functions. The approach is based on the Lie operator representations and the corresponding Lie series solutions. This kind of solutions can be obtained for a general class of non-linear systems in the form of analytical power series. The applica-tion that we propose concerns a method for the identification of the parameters of a mechanical system composed of rotor on two lubricated journal bearings. In this application we have used a set of numerical results obtained by integrating the motion equations, then, developed a numerical procedure in order to minimize the difference between numerical and approximating solution, last, obtained by using Lie series