Relationship between ISO 230-2/-6 Test Results and Positioning Accuracy of Machine Tools Using LaserTRACER

Abstract

Abstract:To test the positioning accuracy and repeatability of the linear axes of machine tools, ISO (International Standards Organization) 230-2 and ISO 230-6 are usually adopted. Auto-tracking laser interferometers (ATLI) can perform the testing for the positioning accuracy and the repeatability including x-, y-and z-axes according to ISO 230-2 as well as xy, xz, yz, and xyz diagonal lines following ISO 230-6. LaserTRACER is a kind of ATLI. One of the steps of the ISO 230-2 and -6 tests using LaserTRACER is to determine the coordinate of the LaserTRACER with respect to the home point of the machine tool. Positioning accuracy of the machine tool causes the coordinate determined error, which might influence the test result. To check on this error, this study performs three experiments. The experiment results show that the positioning error appears on the testing results.

Research on Geometric Errors Measurement of Machine Tools Using Auto-Tracking Laser Interferometer

“…The first step in using ATLI, following ISO 230-2 and 230-6, is to fix the ATLI onto the machine tool carriage [8]. The next step is to determine the ATLI's location with respect to the home/reference point of the machine tool.…”

“…Dr. Lee [8] has discussed the relationship between ISO 230-2/-6 test results and the positioning accuracy of machine tools using LT. This paper will further discuss the trend of the measurement result when only one ATLI is used for the squareness measurement of machine tools or CMM.…”

A Simple Integrated Geometrical Error Model for Laser Tracer

“…The laser tracer holds a high precision reference sphere as the reflection unit whose form error is less than 50 nm, and it can ensure the measurement accuracy by using high precision and high stability laser interferometry system [1][2][3]. Laser tracer owns the advantage of high precision and high efficiency, however, the geometrical errors of 2D gimbal mount axes are the major factors for the measurement accuracy of laser tracer, therefore it is necessary to detect and calibrate these geometrical errors.…”

Research on Measurement Accuracy of Laser Tracking System Based on Spherical Mirror with Rotation Errors of Gimbal Mount Axes

“…According to (14), laser ranging measurement error is independent of the displacement between the center of the cat's eye reflector and PBS. According to (15), laser ranging measurement error is less than 0.04 μm when error motion along the vertical direction of measuring beam is around ±5 μm: …”

“…Interferometer integrated in the laser head of LaserTracer measures the relative displacement from the center of the reference sphere to the center of the cat's eye reflector in 3-D space ( Fig.1.a)) [14]. The center of the reference sphere, which is also the intersection point between gimbal mount axes and laser beam, serves as the origin of LaserTracer.…”