Theoretical and Experimental Studies of Statistical Evaluation Method for Flatness Error

The theoretical and experimental studies of statistical evaluation method for flatness error are conducted thoroughly, and evaluation parameters and corresponding practicable data processing model are provided. Furthermore, a large number of experiments have been done and statistical analysis has been conducted. The results show that the distribution of extract elements of almost 90 percent of the measured planes is accordant with censored normal distribution, which proves that statistical flatness error obeys normal distribution. The characteristic that sample points are random variables is taken full advantage of in the statistic method, and the flatness error can be calculated without the influence of gross error and therefore the rate of waste parts can be reduced effectively.