Study On Influence Of Geometrical Error Of Machine Tools On Precision Of On-line Measuring

On-line measuring can improve the productivity of the factory. So many factories put the on-line measuring into use. But the complexity of the measuring environment reduces precision of the on-line measuring and limits the application in our country.This paper introduces the principle of the measuring in the system of on-line measuring and has a study on the total scheme of an on-line measuring system in NC machining centers, and the main inspecting errors of the system. On analyzing the structure of machine tools, the on-line measuring system has been described by lower body array. According to the error analysis theory of multi-body system, measuring probe branching body and work table branching body have been founded and transformation matrixes have been set up. Finally the method to model the inspecting errors has been studied for the on-line measuring system.Some analyses have been done on the extant methods for identifying the 21 terms geometric error parameters for NC machine tools. Focusing the methods of 22 lines, 14 lines and 9 lines which are now widely used, a deep study has been done on the improvement of 9 lines.Finally, a summary of the research in this paper is concluded and some recommendations for the future research are proposed.