Enhancing machining accuracy reliability of multi-axis CNC machine tools using an advanced importance sampling method

The purpose of this paper is to propose a general precision allocation method to improve machining performance of CNC machine tools based on certain design requirements. A comprehensive error model of machine tools is established by using the differential motion relation of coordinate frames. Based on the comprehensive error model, a reliability model is established by updating the primary reliability with an advanced importance sampling method, which is used to predict the machining accuracy reliability of machine tools. Besides, to identify and optimize geometric error parameters which have a great influence on machining accuracy reliability of machine tools, the sensitivity analysis of machining accuracy is carried out by improved first-order second-moment method. Taking a large CNC gantry guide rail grinder as an example, the optimization results show that the method is effective and can realize reliability optimization of machining accuracy.

Development of NC Machine’s On-Line Inspection Software

Based on Windows operating system, the software of NC machine’s On-line inspection has been developed, the key technology in software development: Set up the comprehensive error model of the inspection system, probe error treatment technology, communication etc. Utilize this software to turn into the procedure of measuring automatically, and can compensate to probe error, the geometric error and thermal error of the machine, have improved the precision and efficiency.