Abstract: In order to improve in-situ inspection accuracy of complex surface components, error factors influencing the inspection accuracy of the on-machine inspection system are discussed and error compensation methods are studied. The main errors of the inspection system are analyzed which contain geometric error of machine tools, pre-travel error of the inspection system and radius error of measuring probe. The geometric error model of a three-axis numerical control machine tool is established and each individual error value is identified and obtained through laser interferometer. For the pre-travel error of the inspection system, a radial basis function algorithm based prediction method is proposed and implemented. Based on the distribution of the pre-travel probe error obtained, an real-time compensation of the error can be performed during the actual inspection process. Considering the probe radius and its compensation of the contact-type measuring system4, a new algorithm is developed to improve the calculation accuracy of the normal vector which will affect the compensation accuracy. To verify the effectiveness of the proposed method, a complex part is exampled. Through the comparison of the in-situ inspection result with that of the CMM measurement, the proposed inspection system can achieve a great improvement of the inspection accuracy.

Key words: Complex component, Error compensation, In-situ inspection, Machining accuracy, Numerical control machine tools