Intelligent Tracking Control For Several Classes Of Complex Switched Nonlinear Dynamic Systems

In recent decades,problems such as external interference,dynamic changes and parameters changes in subsystems often occurred in actual industrial production.This has made the control design of complex switched nonlinear dynamic systems become a hot topic of research.In this thesis,the problem of intelligent tracking control is addressed for several classes of complex switched nonlinear dynamic systems via combining Backstepping technology and adaptive neural network technology with dynamic surface method.Then,this thesis also studies the design method of the intelligent tracking controller and the convergence of the closed-loop systems.The specific work is as follows:(1)The intelligent control problem for a class of non-lower triangular structure uncertain switched nonlinear systems with dead-zone input is solved.Combining the characteristics of the Gaussian functions,the neural networks(NNs)are used to approximate the unknown smooth nonlinear function,which successfully solves the design impact caused by the non-lower triangular structure.The application of dynamic surface control technology avoids the “explosion of complexity” problem caused by the derivation of virtual controls.The Backstepping technology is used to design an adaptive neural network intelligent tracking controller and the Lyapunov function is used to analyze the stability of the closed-loop system.Finally,a simulation experiment verifies the effectiveness of the proposed intelligent tracking control method.(2)For a class of non-lower triangular structure pure feedback switched stochastic nonlinear systems with input saturation,an adaptive intelligent tracking control scheme based on neural networks is proposed.First,radial basis function(RBF)NNs are used in the design process to approximate the unknown nonlinear function.Then,in the framework of Backstepping,the nature of the neural network is used to overcome the design difficulties caused by the non-lower triangular structure.The designed intelligent tracking controller guarantees that all signals of the closed-loop system are semi-globally uniform ultimate boundedness,and the tracking error converges to a small neighborhood of the origin.Finally,a simulation experiment verifies the practicability and feasibility of the proposed intelligent control scheme.