The study on error compensation of the probe system for nano coordinate measuring machine

The probe is called the “heart” of Nano Coordinate Measuring Machine (Nano-CMM). In order to compensate the error of the probe for Nano-CMM, this paper studies the error of the probe, which is the largest source of the measurement deviation. Based on the probe system of Nano-CMM, this paper analyzes the source of the dynamic error system and the influencing factors, studies the compensation for the diameter of the probe. What's more, the paper proposes the method, which is composed of dynamic calibration of probe radius and microplane compensation method. For the sake of the effectiveness of the method, the present paper measures the outline of a concave wheel, which is measured and compared the outline of a concave wheel before and after in reverse engineering software. The results show that the method has a certain better compensation for the probe radius, but, there is existing the small discrepancies at certain points. It proves to be the method can enhance the accuracy of Nano-CMM and have a value for application.

I. Introduction

It is always a hot spot for researchers that how to improve the measuring accuracy of the probe of Nano-CMM. Reference [1] proposed a line structured light based 3D vision probe which works on Nano-CMM. Estler studied the dynamic performance of the probe in [2]. S. Phillips and W. Estler found the pre-travel error which caused by the deflection using the way of establishing the forced model in [3]. Reference [4] suggests that the variation of the error of touch trigger probe system is in the 8.23-8.28 micro range, and the repeatability is0.5micro through the experimental method. At present, the surface or curve fitting is used to compensate the diameter of the probe. While, this method needs to collect the massive data of trajectory, then makes the surface or curve fitting using the least square method in [5], [6]. The calculation is complicated.