A robust model for the discretization of flexible links based on cubic splines

摘要

A robust, finite-dimensional model for a rotating flexible beam is sought. To derive the finite-dimensional model, the structural member is discretized using the two different spatial discretization methods, namely, the normal mode approach andthe finite element method based on cubic splines. The robustness of the resulting control systems is examined in terms of the observation spillover due to estimation errors and the control spillover due to modeling errors. Finally, an analysis usingNyquist plots is performed to examine the behavior of the closed-loop control system, especially around the natural frequencies. Simulation results show superior robustness using the Cubic spline discretization over the normal mode approach.