Error Separation And Accuracy Assessment Of Coordinate Measuring Machine

Development of modern manufacturing has put forward higher speed and accuracy requirement for CMM.especially with the development of the electronics industry,more and more micro devices appearance. In this paper, the new Nano-CMM, which is being developed,is the object of the study.The influences of every error source of the precision of Nano-CMM is analysed On the basis of researching structure characteristic and force analysis of Nano CMM. According to the structure and accuracy demand of Nano CMM, error separation experiment equipment is composed of triple light beam plane reflection laser interferometer SP2000-TR with the departure of measuring head and laser source. Separation solution of each single error of Nano CMM is designed. One-time separation of indication error and linear error is realized. High-accuracy separation method of worktable guide error based on motion instant center is researched which considering that the actual rotating center is supposed to change with the time. The calculation formula of coordinate error of worktable speed center and random points are dedced theoretically and the corresponding error separation and correction method based on the speed instant center are designed theoretically. On the basis of cubic spline principle and double cubic spline function, the program software LabVIEW is used as software platform to program curve fitting and surface fitting of error,provide basic software for the error after amendment. Finally,How to assesst the accuracy of CMM after its error iscorrected is illustrated by the theory.