Robust Output Regulation Control Of Nonlinear Systems With Model Uncertainty

In recent years,output regulation has become a hot spot for its wide application in control theory and practice.Its essence is to achieve asymptotic tracking of reference signals and reject external disturbances by designing feedback controllers.The shortcomings of the existing research results are analysed and the uncertainty of model parameters,unknown dynamic characteristics and the coupling of multi-subsystems are considered.A robust control algorithm based on output regulation theory is proposed.The main research work is as follows:Firstly,the tracking control problem of nonlinear systems with model uncertainty is considered.Fuzzy logic systems are introduced to approximate the unknown nonlinearity of the system.The regulator equations are constructed based on the approximate result.Then,the approximate solution can be obtained as a feedforward information.Therefore,the problem of unavailable precise solution of nonlinear regulator equations can be solved.The transient performance of system is further considered.An adaptive fuzzy prescribed performance controller based on fuzzy logic system is designed.The prescribed transient and steady-state performance of the nonlinear system can be achieved under model uncertainties and unknown disturbances.Secondly,the robust containment control problem of networked systems with parameter uncertainties is investigated.A distributed robust containment control law based on output regulation theory is proposed.By designing distributed observers,it ensures that each follower can estimate state informations of the leaders.The complex output regulation equation is decomposed into a series of solvable linear equations by using power series method.The approximate feedforward compensation for exosystem is obtained by solving the linear equations.The problem of unavailable precise solution of nonlinear regulator equations can be solved.Based on the internal model principle,dynamic state feedback and dynamic output feedback control laws are proposed respectively.Finally,all followers can converge to the convex hull spanned by leaders and the tracking error is small enough.Finally,the effectiveness of the proposed method in tracking control of unknown nonlinear systems and containment control of heterogeneous networked systems is verified by MATLAB simulation.