Abstract: A new kind of method of evaluating roundness error using polar measurement data, which named as mesh searching algorithm, is presented. The principle of the algorithm is that series of polar-coordinate mesh points are collocated around the periphery of the least square circle according to certain rule, the radius value of all the measured points are calculated by regarding each mesh point as the ideal center, the roundness error value of minimum circumscribed method, maximum inscribed method and minimum zone method are achieved accurately through comparing these radius value. The process and step of using the algorithm are described in detail and the mathematical formula and program flowchart are given. The results of the experiment show that the roundness error can be evaluated effectually and accurately.

Key words: computer application, error evaluation, roundness error, mesh searching algorithm