Theoretical Research On Flatness Error Measurement Of Revolving Body End-face

With the development of science and technology, the trend of the measurement technology of form and position error is on-line measurement and high-efficient and intelligent measurement. Flatness error is one of the main elements used for expressing the shape of parts. It plays an important role in form and position error measurement and evaluation. The flatness error measurement using level and autocollimator can not meet the requirements of the modern measurement. Furthermore, on the aspect of flatness error measurement of revolving body end-face, there are few special measuring methods and equipments. The theoretical creation of flatness error measurement is the necessary condition for making a breakthrough on flatness error measurement of revolving body end-face.In this paper, according to flatness error measurement of revolving body end-face, selection of sample points for flatness error measurement and flatness error evaluation method are mainly researched. Selection of sample points for flatness error measurement is a key point, and the influencing factors are analized. On the base of scanning a mass of literatures and considering the research practice, two creative methods of selection of sample points for flatness error measurement are presented. Combining with the least square method, the mathematical models of flatness error evaluation for revolving body end-face are bulit. On this basis, in order to get the more accurate evaluating result relative to the result obtained by the least square method, a feasible optimizing method is used for flatness error evaluation.The main research contents of this paper are as follows:(1)Selection of sample points for flatness error measurement are researched. The influencing factors of selection of sample points including precision requirement of flatness error measurement, the shape of the parts, processing method of the parts, flatness error evaluation method and flatness error measuring equipments are summarized. Every factor influencing on flatness error measurement is analized.(2) According to the shape of the parts, flatness error evaluation method and flatness error measuring equipment, spiral selection of sample points and concentric circular selection of samle points for flatness error measurement are presented, and both of them are discribed by mathematical formulas in detail. Combining with the least square method, the mathematical models of flatness error evaluation for revolving body end-face are bulit.(3)Based on using the research methods of relative subjects of other contries for reference, the simulation method for flatness error evaluation of spiral selection of sample points and concentric circular selection of sample points is presented. Using MATLAB(R2006b) software, the simulation programs are complied. Both of the mathematical models are simulated, and the simulation results are compared and analized.(4)Based on the least square evaluation method, as a optimization method for searching minmum zone, the real-coded genetic algorithm applied in flatness error evaluation is presented. In order to prove that the GA method is feasible, the convex and concave character of flatness error objective function are introduced. Using the GA toolbox in MATLAB(R2006b) software, flatness error are evaluated, and the result is analized and compared with the result obtained by the least square method.