Effect of detector installation error on the measurement accuracy of multi-degree-of-freedom geometric errors of a linear axis

Abstract

A linear axis is the key component of several mechanical machines, especially of computer numerical control machine tools. The simultaneous measurement of the geometric motion errors of a linear axis is indispensable to compensate the machine errors, which improves the accuracy of machine tools. The principle of laser collimation is widely used for measuring the multi-degree -of-freedom (MDOF) geometric motion errors of a linear axis. However, installation errors of the detectors affect the measurement accuracy. In this study, we have proposed, for the first time, a measurement model for investigating the influence of all detector installation errors on the accuracy of the simultaneous measurement of MDOF geometric motion errors in a linear axis. The effect of detector installation errors on the horizontal straightness, vertical straightness, pitch, and yaw are analyzed using the homogeneous transformation method, which indicates that angular installation errors of detectors along the X 0 -axis direction can cause a crosstalk between the two straightness errors and between pitch and yaw errors. In addition, translational installation errors of position -sensitive detectors in the X 0 -axis direction, which is often called the defocusing amount, has a significant effect on the pitch and yaw measurements. To elucidiate the effect of defocusing, a measurement model was verified by both Zemax simulation and experiments. The experimental results indicate that the maximum deviation of the measured results obtained using the proposed model from that obtained using a Renishaw XL-80 interferometer can be greatly reduced by compensating the measurement errors induced by defocusing.

Simultaneous Measurement of 6DOF Motion Errors of Linear Guides of CNC Machine Tools Using Different Modes

“…System errors usually affect the performance of the measurement system, including the manufacturing and installation errors of optical components, the angle drift of the measurement beam, and the installation errors of the detector in the measurement head. These errors can be compensated by adding a common-path beam drift measurement and compensation structure [ 25 ] and establishing an error compensation model [ 24 , 26 ].…”

Development of a Spatial Accuracy Compensation Method Based on Multi-Beam Laser Interferometer

“…The conventional laser interferometer is still considered a highly efficient testing instrument [16]. An innovative upgrading of a single-beam laser interferometer facilitates accurate measurement of all 6 degrees of freedom errors relative to the linear motion axis, leading to multi-beam laser interferometry, as shown in Figure 3.…”