Research on Positioning Error of Dual-Drive Feed System Based on Virtual Axis-Electronic Cam Strategy

Abstract The dual-drive feed system (DDFS) is widely used in highspeed, high-precision and heavy-duty applications due to its good vibration resistance, high rigidity and rapid response. Positioning accuracy is an important performance index characteristic of CNC (Computer Numerical Control) machine tools, which can directly determine the processing quality of the workpiece, but the existence of positioning errors always damages the performance and processing accuracy of CNC equipment. This paper firstly analyzes the source of the positioning error of the DDFS. Then, according to the structure of the DDFS, the multi-body system (MBS) theory and the modeling method of homogeneous transfer matrix (HTM) is used. The error modeling of the DDFS is carried out, and the positioning error model is obtained. According to the positioning error model, a reasonable positioning error detection program is designed. And the experimentally measured positioning error values are fitted. Finally, by using the virtual axis-electronic cam error compensation function in the TwinCAT software of the German BECKHOFF control system, the error compensation method of virtual axis-electronic cam is used on the built DDFS platform to carry out error compensation experiments. The experimental results show that the error compensation method of virtual axis-electronic cam can effectively reduce the positioning error.