Research On The Sliding Mode Variable Control Of Neutral Time-delay Systems With Uncertainty

In the actual controlled system,many development and change rules of the controlled objects can be described by mathematical models of neutral functional differential equations which express the neutral time-delay system,makes the content of the control theory more abundant and is one of the key research of control system.Method of sliding mode control is reasonably applied to the neutral time-delay systems.This paper mainly researches the design of the sliding mode control of neutral time-delay systems with mismatched uncertainties in the input matrix and the unknown input disturbance and Lyapunov stability analysis and adaptive global sliding mode control problems of neutral time-delay systems with state time-varying delay.The correctness of the stability analysis and the feasibility of the control method are verified by programming simulation.Firstly,for a class of uncertain neutral time-delay systems with uncertainties.The input matrix contains parameter perturbation and the input contains unknown disturbance which are all not satisfied the matching condition.The existence of mismatched uncertainties makes the system difficulty to represent accurately.Thus control it become more difficulty.Through a nonsingular transformation,an original time-delay system is changed into a new form without time delay.Based on which,a sliding mode controller is designed and the design process is more simplified.The stability of sliding mode is proved by the criterion is given by Linear Matrix Inequality-LMI according to the Schur theorem.The simulation results show that the controller is effective.Secondly,in order to reduce the conservative of time-delay,for a class of uncertain neutral system with state time vary delay.Lyapunov function makes full use of the low bounds of time-delay and combined with Jensen inequality to deal with functional derivative integral and the identity is built by newton-leibniz formula.The simulation results show that the conservative of time-delay is reduced.Finally,in order to deal with adaptive global sliding mode control problem of nonlinear time-varying-delay neutral systems with uncertainties that the integral global sliding surface with neutral time-delay is designed for the perturbation and external disturbance of the system and realize global sliding mode stability.Weaken the system chattering by using the saturation function to replace the symbolic function.A numerical example is demonstrated for showing the integral sliding mode control is feasible.