The Analysis And Control Based On The Cascade Switched Nonlinear Supply Chain System

The control problem for cascade switched nonlinear system with time-varying delays and supply chain system are studied in this thesis.In the practical industrial applications,due to the material transmission of supply network between suppliers and customers often spends a lot of time,so how to make full use of transmission delay and the consumer demand uncertain for modeling,analysis and design of nonlinear supply chain system is particularly important topic.Backstepping technique is commonly used to deal with nonlinear system,which is a regression design method to combine the selection of the Lyapunov function with the design of the controller.By starting from the system of minimum order differential equation,introducing the concept of virtual control,then designing the virtual control which meets the requirements step by step,finally get out the real control law.Given that there will be the derivative of virtual control which makes computation complexity increases,we adopt the active disturbance rejection control technology solve the uncertainty of the system and virtual control of derivative.In this paper,the main research content includes two parts:the first part studies the cascade switched nonlinear systems with time-varying delays under arbitrary switching control problem,the second part studies the inventory level at a lower level in different league switched nonlinear output feedback control problem of supply chain system.Considering the derivative of the virtual control will appear in the backstepping technique which makes the computational complexity increases,the active rejection control technique is used to solve the uncertainty of the system and the derivative of virtual control.The main research contents include two parts in this paper: the first part studies the control problem for the cascade switched nonlinear system with time-varying delays under arbitrary switching,the second part is the study of the control problem for cascade switched nonlinear supply chain system under the different inventory level.The work of this paper is organized as follows:(1)The first chapter gives the introduction of the switched nonlinear system,supply chain system and the research status at home and abroad,then introduces the main research contents of this thesis.(2)The second chapter studies the modeling and analysis of the control problem for cascade switched nonlinear system with time-varying delays.Consider that time-varying delays are inevitable in practice,we can establish the cascade switched nonlinear system under arbitrary switching.Because of the change characteristics of time-varying delays,there exists unknown nonlinear function in the system.In order to reduce the complexity of the system,unknown nonlinear function can be viewed as uncertainties.Then using extended state observer and nonlinear tracking differentiator to estimate and track unknown nonlinear function and the derivative of virtual control which appears in backstepping design,respectively.Based on the backstepping method to design the actual controller,guarante that all the signals in the closed-loop system will converge to the neighborhood of the origin.Finally,an numerical simulation example is given to prove the effectiveness of the proposed method.(3)In the third chapter,the control problem for cascade switched nonlinear supply chain system under the different inventory level is considered.In this paper,considering the supply chain system is nonlinear supply chain system which contains 9)facilities,where the product of 4)+ 1th facility is supplied to the 4)th facility(4)= 1,2,· · ·,9)-1).Since there exists consumer demand uncertain and time-varying delays in practice,so the uncertainty of time-varying delays is also considered in the system.In addition,because of the different inventory level and different productivity for each facility,then the whole system runs with multiple modes,and we can utilize fuzzy rules to describe these modes.Considering the uncertain time-varying delays,the extended state observer is used to estimate uncertainty.According to the backstepping method,the controller is designed and proved that the system is asymptotically stable.The simulation example verified the practicability and validity of the method.(4)The present research work is summarized in the fourth chapter,and make a prediction for the future work.