Reduce The Application Of Control Input Strategies In Uncertain Nonlinear Control Systems

It is well known that,nonlinear systems are more accurate and more able to show the essential characteristics of the systems compared with linear systems.It is especially common in practical engineering applications,the control design of nonlinear systems has been the focus and difficulty in the field of control theory.At the same time,considering the actual conditions,it is necessary to realize the asymptotic stability of the systems under the condition of small control.It is widely used in robot systems,power systems,aerospace systems and biochemical systems and so on.Therefore,it is of both theoretical and practical value to reduce the control input strategy.The main contents of this paper are mainly carried out from the following two aspects:(I)Adaptive disturbance attenuation for generalized high-order uncertain nonlinear systems.This part investigates the problem of adaptive disturbance attenuation for a class of generalized high-order uncertain nonlinear systems.The control strategy is on the base of continuous domination and delicate adaptive technique,and it can cope with serious coexistence among uncertainties,including time-varying control coefficients which have unknown upper and lower bound,nonlinear parameters and external disturbances,and the control strategy has a lower requirement on the control size.Adaptive state-feedback controller is one-dimensional irrespective of the number of unknown parameters,and its performance is evaluated in terms of 2-2gain.(II)Parameter assignment of a class of saturated controllers for nonlinear systems.This part presents a small control parameter of saturated controllers for a class of nonlinear systems,which takes full advantage of the negative property of the derivative terms and combines with a ingenious coordinate transformation to make the nonlinear systems stable asymptotically.Compared with the traditional backstepping method,the novel control strategy makes the control process more precise and greatly reduces the requirement of the control size under the similar control effect.Finally,a numerical example is given to demonstrate the superiority of the proposed control strategy.