Research On Path Following And Trajectory Tracking Control Of Unmanned Surface Vehicle Based On MFAC Control Algorithm

Unmanned Surface Vehicle(USV)is a miniaturized and intelligent unmanned platform on the water,and it is also the focus of the current research field of intelligent marine equipment.USV is characterized by a wide range of applications.In the civilian field,it can be used for water quality environmental testing,underwater resource exploration and personnel rescue.The military field can perform different combat missions by equipping different combat modules.Motion control is a core function of the USV and is the basis for ensuring that its voyages perform the above tasks on a defined path.Most current USVs are not equipped with thrusters for lateral motion control,which in mechanisms are classified as underdrive mechanisms with a motion input smaller than the generalized degrees of freedom of motion.The underdrive characteristics and the presence of environmental interferences such as wind,waves,and currents in the task environment put forward higher requirements for the design of the USV motion controller.In this paper,the design of the USV Path Following controller and the research work of the USV Path Following controller are carried out,and the research content is mainly as follows:By introducing two motion coordinate systems,the six freedom kinematics and dynamics equations of USV are established.According to the motion control requirements of USV,the six degree of freedom model is simplified to a three degree of freedom model of USV which only focuses on swaying and surging,and yawing.Taking into account the environmental interference during the task,the steady irrotational uniform flow interference is modeled.The simulation results of direct navigation and rotation under flow disturbance verify the accuracy of the model,which provides a basis for the design and Simulation of USV motion controller in the following chapters.Aiming at the assumption that USV heading control subsystem can not meet the requirements of model free adaptive algorithm control system,an improved redefined output is designed.According to the mechanical limiting characteristics of the USV steering mechanism,the controller output limiting function is designed.On this basis,the USV bow direction is planned by using the line-of-sight(LOS)guidance algorithm based on the variable forward viewing distance,and a USV path tracking controller based on the improved algorithm is designed.The stability and effectiveness of the USV path tracking controller based on the improved MFAC algorithm are verified by comparing with the fuzzy PID path tracking controller to track the linear,circular and other paths under environmental disturbances.The USV speed controller based on compact MFAC algorithm is designed,and the USV trajectory tracking controller is designed.A model free adaptive USV trajectory tracking controller based on extended state observer is designed to solve the problem that it is difficult to obtain velocity information when USV performs tasks and the information is distorted due to sensor noise.The effectiveness of the designed USV trajectory tracking controller and extended state observer is verified by the simulation experiments of compound parameter trajectory tracking composed of circular parameter trajectory,linear parameter trajectory,Sinusoidal Parameter trajectory and linear and circular trajectory.