Basic Research for On-line Identification of Physical Parameters Involved in Flexible Structures

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The principal purpose of this basic research is to establish the on-line algorithms for determining physical parameters involved in the model of cantilevered beam such as the Young's modulus, Kelvin-Voigt structural and air damping coefficients. These unknown parameters can not be measured directly no matter what instruments or sensors are employed. The measurement is performed only for the displacement of the beam. So the problem is to construct any computer algorithm for identification by using indirectly measured dynamic data.In order to research step by step, at first the identification algorithm for two unknown physical parameters(the internal damping coefficient and the Young's modulus) of the uniform cantilevered beam is established. Next, by developing the above-mentioned algorithm an on-line computational algorithm for determining the two unknown parameters is proposed for a class of uniform mechanically beams. Then the inverse problem for the spatially distributed (i.e., spatially-varying)model two parameters are considered for the non-uniform cantilevered beam.Needless to say, when we deal with flexible structures on the ground, the effect of the air damping cannot be neglected. Taking the air damping effect into account, a simultaneous identification algorithm is proposed for determining Kelvin-Voigt structural and the air damping coefficient and Young's modulus. For the identification problem about three kinds of unknown parameters, we also construct an on-line identification problem for three parameters. Furthermore we develop the (off-line) identification algorithm for three spatially-varying parameters.The identification method proposed in this research are the indirectly measurement method, so-called 'soft sensor', by which we decide unmeasurable physical parameters using the dynamic measurement data.