Research On Tracing Control Of Double - Body Double Propulsion Unmanned Boat

The unmanned surface vehicle(USV) is a new type of marine observation platforms, it can accomplish observation missions under the manual control or automatic control. The USV can be widely used in environmental monitoring and marine surveying and mapping work. Because these characteristics, it has become a hotspot research in many countries. But the research on the unmanned surface vehicle technology is still in its infancy, that urgently needs us to do some related research and exploration. The path following control is the key technology to the USV control. In this paper, based on the catamaran USV with two propellers, developed by the first institute of oceanography,the state oceanic administration, this paper mainly research work is to design linear control law for the USV path following control problem.Firstly, this paper describes the catamaran USV with two propellers. In order to obtain the resistance parameters of the USV, this paper presents a numerical simulation method to calculate the USV resistance based on the FLUENT software. The viscous flow filed around the floats and their attachments of an USV is simulated using the standard k-ε model and VOF method. The total resistance of the USV is calculated and compared with the lake test results. Research results show that the method is applicable for calculating USV resistance. In addition, the simulation data may used on the USV system identification.Then, simplifying the 6-D model of the ship and only considering surge, sway and yaw, the 3-D mathematical model of the USV is established. According to the experimental data, the system identification of the USV is accomplished and the parameters in the mathematical model are obtained. The open loop simulation of the mathematical model of the USV show the correctness of the model. Based on the mathematical model and LQR control algorithm, joining the two state variables of the course deviation and distance deviation, the course following, waypoint following and path following LQR controller are designed, and simulation experiment was carried out. The LQR controller and PID controller of Straight path following control are compared, the results show that the LQR controller developed by this paper has the better tracking effect and the faster convergence speed.Finally, the designed LQR controller are tested in this paper. The USV can achieve the aim of course following, waypoint following and path following. It also complete a circle path tracking. The results show that the LQR controller has good tracking effect and strong robustness, which can meet the requirements of engineering applications.