Sliding mode control of yarn’s tension based on improved reaching law

When the sliding mode control method based on the traditional exponential reaching law is applied to the yarn's tension control system, chattering phenomenon will increase the output fluctuation of the controller and reduce stability of system. The problem of slow convergence speed will reduce the dynamic response speed and increase the adjusting time of the system. To solve these problems, the sliding mode control method based on improved reaching law is proposed. In improved reaching law, reasonable reaching terms are designed and the continuous function is used instead of symbolic function. The stability of improved reaching law is proved by Lyapunov stability theory. The simulation results show that, compared with the sliding mode control method based on traditional exponential reaching law, the improved method can not only effectively suppress chattering phenomenon, but also improve the convergence speed and robustness. The yarn's tension control system has better convergence characteristic, dynamic performance and stability.