Research On Trajectory Tracking Of Unmanned Vehicle Based On Predictive Control Method

In recent years,model predictive control has been widely used in the field of unmanned vehicle because of its unique advantages in dealing with high-dimensional multivariable and constrained control problems.In this thesis,aiming at solving the problem of trajectory tracking of unmanned vehicles,based on the kinematics model of unmanned vehicles,with linear matrix inequality as the main research tool,combined with Lyapunov stability theory and invariant set theory,the state feedback predictive control synthesis method of trajectory tracking of unmanned vehicles is systematically studied.The main work of this thesis is divided into the following three aspects:1.The trajectory tracking problem of unmanned vehicle based on robust predictive control is studied.Firstly,a linear tracking error model is established to predict the future dynamic behavior of the unmanned vehicle system.Then,a robust predictive controller is obtained by transforming the min-max optimization problem into the online solution of the upper bound minimization problem of the infinite horizon performance objective function.Finally,a co-simulation platform based on Matlab/Simulink and Carsim is built to verify the effectiveness of the robust predictive controller design method.2.The trajectory tracking problem of unmanned vehicle based on quasi-robust predictive control is investigated.Firstly,by transforming the parameter of the infinite horizon performance function into a free control move and a single state feedback law,a state feedback predictive controller with free control move is designed,and a new elliptic invariant set is constructed.Then,the recursive feasibility of the quasi-robust predictive control method is analyzed,and the system stability proof is given.Finally,the simulation results show that the quasi-robust predictive control method reduces the conservatism of the system and effectively improves the performance of the system.3.The trajectory tracking control of unmanned vehicle based on robust predictive control with multiple free control moves is studied.On the basis of quasi-robust predictive control,a robust predictive controller with multiple free control moves is designed,which extends from one free control move to multiple free control moves.It splits the infinite horizon control moves into a set of free control moves over a fixed horizon and a state feedback law in the terminal region,which improves the control performance of the system.Simulation results show that the tracking performance of robust predictive control with multiple free control moves is better than that of quasi-robust predictive control.