Abstract
This paper presents a low-cost on-line system for monitoring the axial thermal displacement of machine tools. The proposed monitoring system includes an embedded optical sensor derived from a laser mouse; an image acquisition microcontroller; speckle patterns; and an edge computer that hosts software including an image display module, a displacement calculation module, an image enhancement module, and a data visualization module. The proposed sensing system can measure the displacement in two orthogonal directions simultaneously by employing digital image correlation; thus, the proposed system is a two-dimensional displacement sensor. The sensing system benefits from image enhancement techniques and customized optimal speckle patterns printed using a standard low-cost monochrome laser printer. Experimental results indicate that the proposed displacement sensing system has an accuracy and a precision of less than 5 mm in both orthogonal directions; however, the measurement range is only 1 mm for a static measurement. The two-dimensional displacement sensing system was used for the on-line monitoring of the thermal deformation of a feed drive system for machine tools, and the performance of the sensing system was assessed experimentally.
Thermal image enhancement through the deconvolution methods for low-cost infrared cameras