The Application Of Monte Carlo Method In Determining The Number Of Extracting Points For Roundness Error

The concept of roundness error comes from the practical project, it refers that the changes from actual contour to desired one on identical section of the solid revolution. The existence of roundness error will affect coordination between contiguous parts directly, will affect the revolving precision and can cause additional friction, vibration and noise. So it will reduce service life of the using parts, will increase energy consumption and so on.Therefore, the precision of measuring and evaluating for roundness error play important roles in qualification judgment and precision guarantee.In recent years, study on methods of evaluating and measuring have made considerable progress, but accurate measurement and evaluation for roundness error directly depend on the extraction of measuring points. Even though ISO has developed related measuring standards on extraction of shape and position tolerance, it has not made systematic and complete regulars on extracting process and criteria of extracting points. This article based on the predecessors’ theory, took the question of extracting points as cole to find out guiding, accurate and operability specifications on determining extracting points.The main research is as follows:(1) Introduce the development of measuring technique and evaluating method at present detailedly, and introduce one linearizing method of roundness error evaluation emphatically, analyze its skillful function in the project application(2)Analyze the key question in roundness error research—extraction (including extracting points and extracting plans), and introduce how the extraction points do significant influence in measurement result and in the result indefinite expression.(3)Use harmonic analysis method to analyze the frequency spectrum characteristics for outline surface of roundness, and survey the different components, the different extraction point to carry on the harmonic characteristic analysis.The result will be used to do error analysis and to instruct the scene production.(4)Introduce the Monte Carlo simulation method’s usage in determining the number of extracting points for roundness error in detail, and analyze its simulation principle, feasible, the simulation operating process and so on.Used some parts which is some size, some precision carry on the sampling analysis, confirmed the accuracy of the Monte Carlo simulation.(5)Confirmed the conclusion obtained in the paper and expect it can apply in practice and instruct the production and so on.The results attained in this article can be good instructions for measurement and evaluation in roundness error and have built the foundation to other aspect research about geometric and form error.