Nonlinear identification of a rotating flexible beam

Most systems that are encountered in practice are subjected to various uncertainties such as nonlinearities, actuator faults parameter changes etc. Modeling and identification of electro-mechanical systems constitute an essential stage in practical control design and applications. For a electro-mechanical rotational system, the nonlinearities, like Coulomb friction and dead zone, significantly influence the system operation when the rotation changes direction. The paper presents the black-box nonlinear identification of a rotational flexible link setup. The nonlinear model for the system is obtained based on the discrete second order nonlinear Volterra model. Off-line identification of the nonlinear system model is performed using the least mean square algorithm. Results of the real time experiments are graphically and numerically presented, and the advantages of the nonlinear identification approach are revealed.