The Design And Research Of Tele-autonomous USV Control System

Nowadays,the automation ability of the transportation equipment which means with out man control is becoming a prevailing trend.All the robots,unmanned aerial vehicles(UAVs),driverless vehicles,driverless ships and the unmanned surface vehicles are receiving lots of social funds,technologies and researchers.As one of the surface vehicles,the USV has been the hot research field in control fields for its small size and rich features.However,there is greater disturbance in the real water environment than in the sky or land,and the real water environment is also more complicated.Further more,the USV is usually underactuated,it only has one propeller and one rudder to control itself move in three degrees of freedom,this greatly enhances the difficulty of control and make the USV has a lower level of automation than other unmanned vehicles.At the same time,there is another problem which is that the sensor capability and algorithm performance can not fit the USV obstacle avoidance problem well.Therefore,focus on these problems above,a tele-autonomous USV control system is designed independently which includes hardware,software and the controllers.A tele-autonomous control algorithm is presented.And by means of simulation and full scale seakeeping trials,the stability and effectiveness of the tele-autonomous USV control system are verified.Firstly,a fixed earth coordinate system and a ship following coordinate system are defined in this paper,they are used to describe the horizontal movement of the USV.Furthermore,the names and symbols of international ship states and parameters are introduced.Then,based on the analysis of the hydrodynamic characteristics and the movement characteristics of the USV,the control model which named Nomoto model is derived through the three degrees of freedom USV movement model.And next,the background and theory of LMI are introduced.The model of the USV path following problem is defined in the {SF} coordinate system.A path following controller which based on the LMI and predictive control is designed.Then,the Collision Cone is introduced to help define the obstacle avoidance model.The obstacle avoidance controller which based on LMI limits is designed,and at the same time,MATLAB simulation experiments are conducted to verify the algorithm above.And then,the design principle and idea of the hardware and software of the USV are expounded.The principle and idea consist of hardware part and software part.The hardware part contains the body,the propulsion mechanism,the steering mechanism and the electric control system.The software part includes the motion control software interface,the communication module,the file management module,the event management module and LMI algorithm implementation module.Finally,the full scale seakeeping trial is conducted.The GPS coordinate transformation problem is solve by the Gauss-Kruger projection theory,and the problem which contains the sensor data mutation and the inaccuracy of rudder are solved.KT experiments are conducted to identify the control parameters of the USV.Besides,the environment and steps of the full scale seakeeping trial are introduced.By analyzing the result of the experiments,the stability and effectiveness of the tele-autonomous USV control system are verified,and furthermore the Limitations of this paper are also found.