Shaojun Wang

Cross-coupled fuzzy logic sliding mode control of dual-driving feed system

Dual-driving systems have been widely adopted in advanced manufacturing machine. Synchronization of the dual-servo systems is crucial for tracking reference trajectories. This article proposes a novel cross-coupled fuzzy logic sliding mode control for the synchronous control of dual-driving feed system. The dynamic model of dual-driving system has been established and the individual proportional–proportional–integral controller is built based on the dynamic model. To increase the synchronous performance, a cross-coupled sliding mode controller is provided based on dual-driving system model. In addition, a continuous saturation function is adopted to reduce chattering. Lyapunov stability criterion is used to analyze the stability of the cross-coupled sliding mode control. Moreover, a fuzzy logic saturation gain control approach is proposed to overcome the low robustness and poor dynamic synchronous performance in the normal cross-coupled control scheme. The adaptive saturation function is designed to eliminate synchronous deviation caused by the process of two axes following each other. Finally, an industrial application of dual-driving system is utilized to prove the effectiveness of the proposed scheme. The proposed cross-coupled fuzzy logic sliding mode control scheme has been effectively demonstrated to improve synchronous performance and tracking accuracy.

Dynamic Characteristics Analysis and Test of Dual-Driving Feed System Driven by Center of Gravity

Dual-driving feed system (DDFS) driven by center of gravity (DCG) has been widely used in advanced manufacturing machine for its high rigidity and precision. However, the DCG technology requires that the joint force coincides with the center of gravity of the sliding stage. The dual-driving synchronization and tracking performance will be affected by the change of center of gravity of the sliding stage. Therefore, this paper proposes dynamic characteristics modeling, identification, and control scheme for DDFS driven by center of gravity (DCG). Firstly, a redundancy dynamic model including rotation and pitch vibration caused by the change of the position of center of gravity is presented for DDFS DCG based on the Lagrange method. The model parameters are identified by system identification experiment, and the predictive natural frequencies and vibration modes by the proposed dynamic model are compared by modal experiment. Moreover, the dynamic model-based cross-coupled sliding mode control (CCSMC) is proposed for DDFS DCG. Then, the proposed dynamic model-based CCSMC has been compared with normal cross-coupled sliding mode control (NCCSMC). Both the simulation and experimental results show that the proposed dynamic characteristics analysis and test scheme of DDFS DCG are validated effectively by comparisons.