Renovation Of YD200A Roundness Tester With Virtual Instrument

The rapid development of computer science has brought about a new revolutionary change in the measuring instrument, and brought forth virtual instruments, which represents the direction of the development in the field of automatic testing and electronic testing instruments in the 21th century.The dissertation expounds the history of the appearance, and development, definition as well as the features of the virtual instruments. Furthermore, the paper gives a detailed introduction to their structure, components, principle, function and applications in a variety of the fields. At the same time it gives a general view of the future. Besides, the author, based on the general knowledge of virtual instruments, makes a feasibility analysis of the virtual renovation of the traditional YD200A roundness tester, therefore offers a structure plan for the software and hardware used in the virtual instrument system based on the PCI bus card inserting form. The dissertation expounds the selection assembling and works of various modules forming the hardware of the virtual instrument as well as the software, such as the designs of the instrument panel, data collection, analysis and processing of the whole system, visualization output of result. In addition, the dissertation provides the basic principles of evaluating roundness error through computers and corresponding calculating methods and produce the system error, studies four methods for evaluating roundness error through computers and corresponding calculating methods and procedures. and analyzes various factors that produce the system error. the author designs the testing and processing procedures of the radial eccentricity and axial skewness brought about by the insertation of the card to be tested and puts forward a software treatment plan through for separating chief axis rotation error from testing result through "reversion method".The virtual instrument designed in the papers is used for practical test of the axis roundness errors, whose results show: in comparision with the traditional, measuring and data processing methods. the virtual instrument is not only in its easy structure, but also in the automation, digitization and visualization of testing process. At the same time it greatly increases testing and data processing speed. and the testing accuracy.