Point-plane distance as model for uncertainty evaluation of coordinate measurement

Abstract

The paper presents a detailed theoretical background for coordinate measurement uncertainty evaluation by means of Type B evaluation method, taking into account information on accuracy of a coordinate measuring system given with the formula for maximum permissible errors of length measurement and verification test results. A proposal for evaluation of the verification test results is made. A measurement model based on the point-plane distance equation is presented. A detailed analysis of the partial derivatives (sensitivity factors in an uncertainty budget) of the measurement model is presented. The analyses of measurement uncertainty for different geometrical characteristics were conducted using this measurement model. Examples of uncertainty evaluation for geometrical deviations are presented: position of a point related to a datum plane and flatness in the case of convex or concave surfaces. The examples include detailed uncertainty budgets.