Geometric and dynamic error compensation of dual-drive machine tool based on mechanism-data hybrid method

The dual-drive machine tool (DDMT) employs a dual-ball-screw feed system (DBSFS) for high-end manufacturing. However, geometric and dynamic errors significantly diminish tool center point (TCP) precision. Addressing two-axis positioning errors is vital for error compensation. The paper introduces a novel unified comprehensive error model that illustrates the error transfer mechanism in DDMTs. This model is applicable not only to DDMTs of various structural types but also to single-drive machine tools. The innovation is that the geometric and dynamic errors are simultaneously compensated based on the error generation mechanism and error data hybrid method. The cross-coupled control strategy with the proportional-differential controller is used for the DBSFS during compensation to consider the coupling characteristic of the two-axes tracking error and non-synchronization error. The dynamic error is predicted by the proposed dynamic model, which can reveal the mechanism of error generation. Based on error sensitivity analysis, the geometric error prediction model is established by combining geometry error data with leastsquare method and grey wolf optimization. Comparison simulation and experimental results validated the superiority of the proposed compensation method over existing ones in practical applications, showing a decrease in the positioning error of the TCP and non-synchronization error of the DDMT over 41% and 35%, respectively.