Modeling of Moving Table with Linear Roller Guides Subjected to Geometric Errors In Guide Rails

This paper presents a model of a linear roller guide that considers geometric errors in rails. A five degree-of-freedom model of a table supported by linear roller guides with guide rail errors was built to determine table-motion errors during its motion along erroneous rails. The model was verified by comparing the simulated displacements of a linear guide estimated by the proposed model and those by an existing transfer-function method. Two types of geometric errors were considered for the guide rail: general form and waviness errors. The influence of external load, initial preload, and a few important parameters of the rail-such as wavelength and amplitude-on the displacement of the carriage and table were investigated extensively. The simulation results demonstrated the ability of the model to obtain complicated motion errors for moving tables with a number of supporting linear guides subjected to guide errors.