Research On Virtual Measurement Technology Of The Form And Position Errors

In the mechanical products, especially the mechanical products with a high precision, the geometrical error of the workpiece is important to check on the machining precision, and it is also one of the essential factors which influence the performance and the quality of the mechanical products. The measurement theory and technology of the form and position errors had been researched into by many expert for years. Although many achievements in this field, there are also many problems to be solved, especially in the aspects of the form and position errors graph produced and measurement on virtual instrument. This thesis deeply studies the fundamental theory and the software system of the form and position errors visual evaluation system based on the LabWindows/CVI software platform is designed in this paper.The main content of the research work is the following.This thesis studies the fundamental theory of drawing the form and position error graphs, mainly including computer graphics knowledge and the mathematical models of drawing error graphs.The mathematical models of graph have been established for evaluation of roundness errors by least square circle, minimum zone circle, minimum circumscribed circle, and maximum inscribed circle methods, of cylindricity errors by least square cylinder, minimum zone cylinder, minimum circumscribed cylinder, and maximum inscribed cylinder methods, of axial straightness errors, coaxiality errors,radial circular run-out errors, radial whole run-out errors by least square and minimum zone methods.On the basis of the theoretical research, the form and position error visual evaluation system is developed by using LabWindows/CVI as software platform. The fundamental theory and mathematical models for drawing the form and position graphs are proved to be true by simulation. The establishment of software library makes the evaluation and the visualization of the form and position come true.