APPARATUS FOR ANALYZING ROUNDNESS FIGURE

PURPOSE:To make it possible to measure roundness with practical accuracy by machinery of computer standard, by successively checking the temporary center of a given roundness figure and further employing a sequential detection method while a moving unit is made smaller. CONSTITUTION:An inputted roundness figure is divided into (N) points to set the center of gravity thereof as the temporary center, and the distance Rmax from said point to the max. point on the figure as well as the number imax of said point and the distance Rmin to the min. point as well as the number imin are calculated. The value of Rmax-Rmin give out of roundness at said point. Next, corresponding to the distance between the center point when the figure is inputted at first and the center-of- gravity position of each point subjected to interpolation processing, moving units of almost three large, medium and small stages are set. Subsequently, an arrow C bisecting arrows A, B is calculated from the temporary center P0 and set to a moving direction. According to this numerical value and the direction, the temporary center is moved by the moving quantity of measure and the roundness at that point is calculated. Next, this roundness is compared with the roundness calculated previously and the temporary center is further moved to compare the out of roundness. This operation is successively repeated to calculate desired out of roundness.