Spatial angle error equivalence principle and on-machine detection method for 5-axis machine tools

Affected by manufacturing and assembly accuracy, geometric errors (GEs) are inevitable in 5-axis machine tools. Studies show that these GEs reduce the machining accuracy of the workpiece. Therefore, it is of significant importance to detect and compensate for these errors. In this regard, an accurate, efficient, and simple method is proposed to detect GEs, improve the accuracy of machine tools, and reduce operational difficulty. In order to simplify the detection process, a model was established to reduce the dimension of geometric errors by analyzing the accuracy retention of GEs of a 5-axis machine tool. Then, two types of testing equipment were designed based on the on-machine measurement technique. Accordingly, the detection process was simplified and the detection efficiency was improved. Finally, the proposed model was applied to the impeller machining process. The experimental results show that applying the proposed method significantly improves the manufacturing accuracy of the impeller. The error of blade profile and the impeller imbalance were reduced by 42.9% and 41.7%, respectively. It is found that the GE detection method reduces the detection time from 505 to 45 min. The performed analyses reveal that the proposed method and testing equipment is effective and efficient, and can be used in engineering applications.