Study On The Measurement Of Roundness And Straightness For The Inner Hole Of The Large Diameter Long Pipes

The measuring principle of roundness and straightness for the inner hole of the large diameter long pipes is discussed in this paper, which is based on the research of the status in quo and the trends on this area. Many measuring methods are analyzed and compared here. According to this, the overall structure of the measuring apparatus and the principle of optical circuits and electrical circuits have been contrived. The measuring error of the roundness for long pipe holes and the space straightness is analyzed and evaluated by using the least squares method and the least condition principle. The mathematical model and the data processing program have been created accordingly. The measuring error of the measuring system has been analyzed and calculated. The design of the scheme and structure for the measuring system has been realized.The measuring device dolly discussed in this paper has made a greater innovation compared with other measuring devices. During its measuring, it can collect the data, process the measuring error on line, and display the information of any section on the pipe completely. This device overcomes the disadvantage: only the qualitative research can be done, but the quantitative research cannot be done, which is common in other measuring methods. The result of this system research also provides important reference for other correlative design.