Dynamic Modeling of a Piezo-Driven Fast Tool Servo System With Coupling of Cutting Load

Abstract Fast tool servo (FTS) diamond turning is a promising method for ultra-precision machining, because of the fast oscillation of the FTS, optical devices with complex shapes can be fabricated with ultra-precision. Form accuracy during fast tool servo diamond turning is a critical issue in the manufacture of optical components. Considering the dynamic oscillation of the tool, the dynamic performance of the servo is crucial for the quality of the shape produced by the servo cutting. Although much research has been done on static errors, little attention has been paid to the effect of servo dynamic errors on surface quality. In this study, a 3D bridge-type enlarged fast tool servo (FTS) mechanism dynamics model was designed to predict the dynamic performance of real machining. First, the kinematics of the mechanism are analyzed, and then the Lagrange kinetic equations are used to dynamically model the designed model, comparison with finite element analysis by mathematical modeling, the model is able to predict the relationship between input voltage and output displacement under different load conditions during machining. The relationship between input voltage and output displacement is simulated by finite element method under the same input voltage and different load, which verifies the rationality of the designed dynamic model.