Design Of Output Constraint State Feedback Controller For P-Type Lower Triangular Stochastic Nonlinear System

In recent years,with the continuous development of science and technology,modern practical industrial systems have become increasingly complicated.In addition,higher requirements have been put forward for the performance of the control system.In a series of the industrial system models,the control problem for the representative P-type lower triangular stochastic nonlinear system has attracted wide attention from scholars at home and abroad.Because this type of system is more accurate in describing the practical industrial system,it can better reflect the essential characteristics of the practical industrial system.Therefore,the control design of this type of system is often a hot and difficult point in the field of control theory.By the backstepping method and based on the Lyapunov stability theorem of the stochastic system,this thesis investigates the controller design problem for the P-type lower triangular stochastic nonlinear system.The influence of many factors,such as output constraints,unknown control coefficients,uncertain parameters,stochastic disturbance and so on,on the controller design and stability analysis are considered.The research content of this thesis is mainly carried out from the following two aspects:(1)For the P-type stochastic nonlinear systems,an adaptive control method with output constraint characteristics is studied.By constructing the tangent barrier Lyapunov function to ensure that the system output does not violate the constraints,a symmetric function model is established to deal with the output constraints in the system and the unknown parameters in the system are estimated by the adaptive estimation method.The controller and adaptive law are designed with backstepping method and the power integral method,then conclude the asymptotically stability of the system in probability.The stability of the system is analyzed by combining the stochastic system Lyapunov stability theorem.A simulation example is used to verify the effectiveness of the proposed method.(2)This thesis further considers the influence of the unknown time-varying control coefficients on the P-type stochastic nonlinear system,and presents the design method of the finite-time state feedback controller for the P-type stochastic nonlinear system with output constraint characteristics.Choose the tangent barrier Lyapunov function to ensure that the output of the system will not exceed the predetermined range,and establish a symmetric function model to deal with the output constraint in the system.Based on the recursive design idea and the power integration technology,the finite-time state feedback controller of the system is designed.Combining with the finite-time stability theorem of stochastic system to analyze the stability of the system,finally,a simulation example verifies the effectiveness of the proposed method.