Research on Synchronous Control Strategy of Dual-Drive Feed System Based on Fuzzy PID Control

Dual-drive feed system (DDFS) is widely used in computer numerical control (CNC) machine tools. In the process of machining, it is necessary to ensure the complete synchronization of the two axes of the feed system, otherwise it will affect the machining accuracy and shorten the life of the machine tool. Due to the structure error of the DDFS and the uneven distribution of the load on the two axes in the process of machining irregular workpiece, there are synchronization errors between the two axes. Therefore, it is of great significance to reduce the synchronization errors by studying the dual-drive synchronous control strategy. In this paper, fuzzy control is introduced into traditional PID synchronous control strategy. Compared with traditional PID control, fuzzy control has the characteristics of high robustness and high control performance. Firstly, the PID model of single-axis servo feed system is established. Then, the master-slave control strategy is selected as the dual-drive synchronous control strategy and the model of master-slave control strategy based on conventional PID (MSCS-CPID) is established. Next, the fuzzy PID control is introduced into the current loop of the servo feed system and the model of master-slave control strategy based on fuzzy PID (MSCS-FPID) is established. The simulation results of the MSCS-CPID and the MSCS-FPID show that the DDFS under the MSCS-FPID has faster response speed and smaller synchronization errors. Moreover, the DDFS under the MSCS-FPID has better synchronization performance after external interference. Experiment confirmed that the synchronization performance of the MSCS-FPID is better than that of the MSCS-CPID.