Sliding Mode Compensation Control for Diaphragm Tension in Unwinding Process of Lithium Battery Diaphragm Slitting Machine

In order to solve the problem of tension control in the actual unwinding process of the lithium battery diaphragm slitting machine, the dynamic model of diaphragm and slitting machine unwinding system is constructed in this paper based on the diaphragm deformation in the unwinding system during the sampling period, in view of the nonlinear system characteristics of the unwinding system and the unstable diaphragm tension caused by the uncertain interference and the inaccurate model in the unwinding process. Considering the unwinding system characteristics of multi-output and strong coupling between outputs, a multi-variable comprehensive sliding surface for balancing unwinding diaphragm tension and unwinding speed, and a sliding mode controller for controlling the diaphragm tension in unwinding process are designed. And the stability of the sliding surface and the controller is proved. The fault-tolerant improvement of the sliding mode controller is carried out for practical engineering application, and the differential tracking disturbance observer is proposed to quickly estimate and compensate the external disturbance of the system. Finally, the results of the comparative experiments verify the effectiveness of the proposed diaphragm tension control scheme.