Research And Implementation Of Cooperative Obstacle Avoidance For Unmanned Surface Vessel

Unmanned surface vessel is a kind of autonomous surface movement platform based on mission purpose,which has the advantages of flexibility,safety,concealment,strong adaptability,intelligence and autonomy.Unmanned surface vessel will inevitably encounter obstacles such as rocks,buoys,piers,large cargo ships,etc.In order to complete the established navigation mission and prevent collision accidents,unmanned surface vessel needs to be able to detect the water surface with high intelligence and adaptability.In this thesis,according to the unpredictable interference of environmental obstacles when unmanned vessels actually carry out navigation tasks,unmanned boats are required to change routes according to obstacles,and the following research is made on cooperative obstacle avoidance of unmanned vessels.Firstly,a set of motion control system which can be used for autonomous navigation and obstacle avoidance of unmanned vessel is designed.According to the needs,the appropriate onboard sensors are selected,and the sensor configuration,debugging and data analysis are carried out.The communication data protocol between onboard control system and shore-based control platform is established.The core control board that meets the needs is designed and developed based on Loongson 1C chip.The embedded software is written with RT-Thread operating system.The shore-based software client developed by QT environment is used to complete the data interconnection between shore-based and unmanned vessel.Secondly,after studying the related theories of autonomous obstacle avoidance for unmanned vessels,an autonomous obstacle avoidance method for unmanned vessels based on LOS navigation method is proposed,and an obstacle data weight processing method based on Gaussian function is adopted.The PID control algorithm is used to adjust the speed and heading in real time,and the Simulink tool is used for simulation comparison test.Combined with the unmanned vessel model,wind,wave and current interference are added to the model,which theoretically shows that this obstacle avoidance method meets the actual obstacle avoidance needs and has certain advantages.Finally,the unmanned vessel autonomous navigation obstacle avoidance tests are carried out,which are single obstacle obstacle avoidance test and multiple obstacles obstacle avoidance test.Using the motion control system test platform designed in this thesis,the reliability of the hardware platform and software design is verified.The test results are consistent with the simulation results,and the feasibility and effectiveness of the autonomous obstacle avoidance strategy proposed in this thesis are verified,which can satisfy the autonomous obstacle avoidance navigation of unmanned boats in real water environment.