The Research On Uncertain Time-delay System Sliding Mode Control

In the case of the outside disturbance and change of the system parameters, the sliding mode variable structure control has strong robustness. The sliding mode variable structure is used in the various systems, especially in the complex nonlinear system and uncertain systems. The actual system is often accompanied with uncertain factors, not only in the internal parameters of the system and the system structure but also in the outside of the system. On the other hand, the phenomenon of time lag is widespread in the actual industrial process. Due to the universal existence of the phenomenon of uncertainty and time delay in the actual production control system, they will result in the instability of the system performance, and it is difficult to achieve the goal of control and production efficiency. Hence the existence of uncertainty and time delay in the system must be analyzed and researched, and their effects on the system have to be fully considered. In this paper, the main studies include three parts.Aiming at the control of a class of time-delay uncertain fractional order systems tracking target signal, a reasonable sliding mode surface is put forward; based on the Lyapunov stability theory, the sliding mode control law is designed to realize the tracking of the target signal; and the numerical nsimulation shows the the effectiveness of the designed sliding mode control law. But the control input exists the phenomenon of chattering, in order to solve this problem, further fuzzy switching gain sliding mode control is put forward, and the simulation are carried out to verify the effectiveness of the proposed method.For the synchronous control of a class of time-delay uncertain Lorenz chaos system, the learning of RBF neural network is used to estimate the uncertainty of chaotic system. By the combining neural network with the sliding mode control, the one-dimensional control input is designed to realize the synchronization of time-delay uncertain Lorenz chaotic system.The sufficient condition of synchronization control is obtained by the Lyapunov stability theorem; the effectiveness of the proposed method is verified by digital simulation finally.For the projective synchronization problem of uncertain fractional order chaotic systems with delay, the sliding mode control algorithm is adopted based on index reaching law. According to the specific system model, the suitable sliding mode surface is put forward; based on index reaching law, the sliding mode controller is designed to improve the approach speed; the sufficient condition of projective synchronization of the main system and subsystem is obtained by the Lyapunov stability theorem; the effectiveness of the proposed method is verified by the numerical simulation experiment finally.