A status review of volumetric positioning accuracy prediction theory and static accuracy design method for multi-axis CNC machine tools

The volumetric positioning accuracy of multi-axis CNC machine tools indicates the deviation from desired to actual position of the tool; it directly influences the machining accuracy of the workpiece, and it is also one of the important indicators to measure the performance of the machine tool. The volumetric positioning accuracy of machine tools is supported to be fundamentally improved. The accuracy design methods for machine tools currently include a robust design method for machining accuracy and static geometric accuracy. The robust design method for machining accuracy is set up based on the effective evaluation of the volumetric positioning accuracy of machine tools, and the geometric error elements are used as the analysis variables without directly directing the tolerance design. The joint surface tolerance of key components is used as the analysis variable in the design method for static geometric accuracy, which is supported to be optimized according to the accuracy design requirements of different machine tools. The present paper summarizes and analyzes the aspects including the volumetric accuracy modeling, identification of geometric error elements for axis of motion, robust design method for machining accuracy, tolerance modeling, and design method for static geometric accuracy of machine tools, and analyzes the key problems to be solved in the method of improving the volumetric positioning accuracy of multi-axis CNC machine tools, and then a feasible research idea to improve the volumetric positioning accuracy of multi-axis CNC machine tools is proposed.