Research On Motion Control Of Unmanned Surface Vehicle Based On Line Of Sight Method

With the development of unmanned surface vehicles(USV)technology in the sea,it shows great application prospect.Unmanned surface vehicles have an extremely wide application prospect in military and civilian fields.In the civilian field,it can be used as a robot that can perform actual work on the water surface.For example,the sea surface can be monitored.When the sonar device is equipped,the underwater bottom can also be scanned.It also has extremely broad application prospects in the military field and can be used as a military weapon,such as anti-terrorism operations,offshore operations,sea surface monitoring and detection.There are two main types: remote-controlled unmanned boats and intelligent unmanned boats.The development of intelligent unmanned boats has been favored by various countries among these two types.This paper first analyzes the development status of USV and their motion control at home and abroad.And proposes a method combining parallel approach and line of sight for the stability and reliability of the current unmanned surface vehicles control system.This is a new applicability motion control algorithm.The algorithm greatly reduces the yaw error caused by the original motion path caused by the interference of exsternal environmental factors.Thereby improving the stability and reliability of the unmanned boat.In addition,the paper also implements the obstacle avoidance function based on the binocular ranging algorithm.The main research work of the thesis is as follows:First of all,the paper designs the USV motion control system and gives the overall framework of the system.And built a hardware platform for the realization of the entire control algorithm.USV control system can be divided into three control modes: manual control mode,automatic control mode and remote-control mode.What's more,the paper also introduces the communication protocol of the whole system.Secondly,the core motion control algorithm is proposed,which is the line of sight method combined with parallel approach method.This algorithm is based on the navigation system.Firstly,mathematical modeling is carried out according to the control system.The kinematics and dynamics are separately modeled.Then,real-time feedback data was convergent to the preset route by calculating the line of sight Angle and line of sight position so that the motion control system of the unmanned boat can achieve real-time correction.The discontinuity of real-time navigation and positioning is also solved by coordinate transformation.The line of sight control method is realized finally.Thirdly,this paper presents a new method for obstacle avoidance of USV.The flow chart of algorithm is designed.Improved calibration algorithm and image preprocessing is used to remove the influence of water and detect obstacles.Then using stereo matching to obtain the parallax image,and the measured distance was obtained by depth calculation.Finally,the target obstacle ranging data is used to avoid obstacles,and the whole measurement is realized so as to achieve the whole range of obstacle avoidance algorithm.Finally,the line of sight control algorithm of the control system is tested and experiment on the ranging and obstacle avoidance system.And compared with the parallel approximation method.Therefore,the feasibility of the control algorithm and obstacle avoidance method of USV is verified.