Positioning Accuracy Test For NC Machine Tools Based On Laser Interferometer And Data Processing Algorithm

Positioning accuracy of NC machine tool is a critical one of accuracy parameters, which directly influences machining perferomance, and is a basis for other geometrical performances. The positioning accuracy measurement is prior work for the improvement of the accuracy and performance, whose level restricts the accuracy of NC machine tool, furtherly, the development of maching industry. Therefore, many scholars and researchers are studying measurement methods and techniques for the positioning over all countriesFor this purpose, the thesis researches the measurement for the positioning accuracy of NC machine tool based on laser interferometer. Existed commercial interferometer has some restrictions that testing need to input nominal positioning information such as target points, range, spacing in advance, and is out of work for the measurement poor accuracy positioning in some occasions. To deal with the problems, data processing and algorithm is discussed. By modeling for test signal and feature analysis, self-lock method for positioning point based on displacement is proposed and developed in principle. More over, threshold method based on velocity is also presented.The software including procedures, GUI interface and simulation is achieved for self-lock method positioning point based on displacement using MATLAB development environment, whose debugging and result prove a good feasibility. In order to validate the measurement method and data processing method, experiments of positioning accuracy measurement for NC machine tool based on the commerical laser interferometer system are implemented, which acquires whole and relatively continuous signal by sampling. And the signal is processed by the developed algorithm to extract positioning point information. So, measurand positioning point value and further main evaluation parameters are calculated by using these point information according to national standard GBT17421.2 or ISO 230-2 <Test code for machine tools. Part2: Determination of accuracy and repeatability of positioning numerically controlled axes>.