An Evaluation Method for the Roundness Error Based on CurvatureLI Xiu-ming, SHI Zhao-yao College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing 100022, ChinaAbstract:A novel method for evaluation of the roundness error based on curvature is presented. The condition for choosing points is derived from the definition of the curvature in evaluating the roundness error with maximum inscribed circle or minimum circumscribed circle. The points with the least radius of curvature are eliminated with maximum inscribed circle, whereas the points with the largest radius of curvature are eliminated with minimum circumscribed circle. According to the above condition three points satisfying with the criterion for evaluation of the roundness error are discovered, so the roundness error is determined, The points are divided into outer points and inter points according to the least square mean circle in order to reduce the amount of computation. The points are eliminated from internal points for maximum inscribed circle, but for minimum circumscribed the points are chosen from external points. The correctness and the feasibility of the method are proved through an example.[著者文摘]
Key words:Metrology; Roundness error; Curvature; Maximum inscribed circle; Minimum circumscribed circle
