Modeling and analyzing the main modes of an ultra-precision stage with lumped parameter method

A lumped parameter model (LPM) is presented to model and analyze the main modes of an ultra-precision stage. The modes of actuator system, measuring system and their summation are discussed based on the analysis of the LPM. Since the measuring system is a coupled and nominal symmetric system, the influence of asymmetry in stiffness to the final visible frequency response functions (FRFs) is examined. Experiments in system identification and modal shape detection are conducted to validate the model.