The Under Actuated Surface Vehicle Formation Tracking Controller Design

The under actuated surface vehicle with its under actuated control features has become more commercial and more value in military field This paper described the design of the under actuated surface vehicle track controller and developed its relevant simulation system, it began with established the mathematical model and then designed track controller especially fleet tracking controller, at last, researched the above aspect with the designed simulation system.This paper combined with the typical coordinate system definition and general three degrees of freedom ship model, established the under actuated surface vehicle model that covers the surge,sway and bow wave three degrees of freedom; it called simplified mathematical model . This paper also introduces the unmanned craft water-jet propulsion model and analyzes its propulsive efficiency; Modeling of wind and waves,designed for control systems with perturbation cases provide disturbance model; completed the path tracking PID controller based on vision method about the under actuated surface vehicle comprehensive model.Firstly, designing a formation ship trajectory controller base on the law of leader-following method. in the case of the situation with external disturbance .In the assumption of that the leading vessel position and heading angle has been known and the speed has bounded with the known value the target of controlling is decomposed into two subtasks, one is kinematics loop control task and the other is dynamics ring control tasks, combined with the back stepping method and sliding mode variable structure method, this paper completed the designing of under actuated ship formation theoretical controller that use the singular sliding mode method and analyzed the stability of the controller.Second, the under actuated unmanned craft simulation system is developed. and the result of the above theoretical design simulation can be validated. The simulation system structure is consist of the upper machine and the lower machine. the PC program in the upper machine is developed by Matlab Simulink module and it realized the numerical simulation and analysis of the under actuated surface vehicle control tasks; the under a machine combine VC programme with Vega Prime software, realizes the simulation of 3 d visualization about the under actuated surface vehicle and this simulation system using the network communication for data exchange.Finally,using the above simulation system to carry out the boat formation control simulation results that in the case of without interference situations and different sea condition The simulation results show that if there is no interference, the following ship can quickly get the expected position that guided by the leader ship even in the around the corner of the track path with a small error .After bringing in the sea conditions of level 1 and level 3, the following ship performance has been influenced by wind and waves, the relative position between the leader ship and the following ship is not constant, but it can still maintain the overall stability. Simulation results verify the above research contents and results that include the mathematical model of the under actuated unmanned craft and the formation tracking controller design.