Research On Heading Motion Control Of Unmanned Surface Vessel

Unmanned surface vessel(USV),as a mobile and flexible surface ship,hidden in action,not vulnerable to enemy attacks,has been widely used in both military and scientific research.Due to its small size and shallow draft,the uncertainty of its mathematical model and nonlinear disturbance will be enhanced when navigating in rough sea conditions,so the problem of disturbance-rejection for its motion control is particularly important.Therefore,in this paper,by using the extended state observer to estimate and compensate the total disturbance(perturbation of model parameters + external disturbance of stochastic ocean waves).At the same time,considering the engineering feasibility of the algorithm for the control system,the heading control problem of the USV in rough sea conditions is solved.Firstly,a three-degree-of-freedom(yawing,swaying and surging)mathematical model of USV based on the momentum theorem and momentum torque theorem is established,a simple model of rudder is given and the mathematical model of wind,wave and current environmental interference is established,which establishes the base for the design and experimental analysis of USV heading control system.Secondly,the idea of active disturbance rejection control(ADRC)is introduced,at the same time,convenient for controller parameter tuning and embedded implementing,the linear ADRC with scaling and parameterization is adopted,and the principle and function of its each component are analyzed.Then its stability analysis is presented.Based on this,according to the requirements of heading control function to be realized for USV,a USV ADRC controller based on bandwidth tuning is designed,and the heading PID controller is also designed.The digital simulation(hull and external sea wind,wave,flow and other modules)of heading disturbance rejection control of the USV and the physical prototype of ADRC based on embedded ARM9(under Linux environment)are built.The simulation experiment of the USV heading disturbance rejection control system is completed.Finally,under the condition of no external environment interference,large-scale perturbation of system model parameters and severe sea conditions,the control quality of the heading tracking and keeping of the designed controller is verified.The simulation curves of heading and rudder angle and statistics are given.Simulation results show the designed USV heading disturbance rejection control strategy is simple,intuitionistic,and has the advantages such as fast response and small overshoot,and exhibits good control performance.It has better disturbance rejection ability and robustness than PID controller.Meanwhile,the designed and implemented USV heading disturbance rejection controller physical prototype based on embedded in this paper has good real-time performance,which satisfies the requirements of the USV heading control accuracy under the rough sea conditons,and it has a certain practical reference value.