On-line linear guideway monitoring using laser mouse sensor

Abstract

Abstract A low-cost, on-line linear guideway straightness monitoring system for machine tools is presented. The monitoring system which includes an embedded optical sensor from the optical mouse, an image display module, a displacement calculation module, an image enhancement module and a data visualization module are integrated into an edge computer. This proposed sensing system can measure the displacement in two orthogonal directions simultaneously, i.e. a two-dimensional displacement sensor based on digital image correlation, DIC. With image enhancement technique and a custom-made speckle patterns printed using a standard low-cost monochrome laser printer, results show that this two-dimensional displacement sensing system has a displacement resolution less than 5 µm in both orthogonal directions. The measuring range is 1mm for static measurement but is effectively infinite while moving at a low speed less than 0.05m/s. However, the accumulation error increases with the measuring range. A novel application of utilizing this displacement sensing system upon online monitoring the linear guideway healthy status, i.e. linear guideway straightness, of machine tools is presented. The performance and the associated advantages and disadvantages of this proposed sensor as well as the on-line monitoring system is assessed experimentally.