Design Of Unmanned Surface Vehicle Test Platform And Research On Collision Avoidance Strategy

Unmanned Surface Vehicle(for short,USV),is a kind of surface unmanned vessel that uses modern intelligent equipment for remote control or network autonomous control.With the rapid economic development and growing energy demand,the diversified operational tasks and complex marine environment have put forward higher requirements on the motion performance and collision avoidance of USV.Therefore,in this paper,by building an USV test platform,equipping the USV with navigation radar,improving the algorithm to process the radar image,and studying the collision avoidance strategy of the USV under various encounter situations.The USV test platform include six parts: USV hull,radar system,GPS system,propulsion and power supply system,communication system and USV control system.The USV hull is a catamaran and the equipment on board is powered by lithium batteries and solar panels;the radar and GPS systems provide obstacle information and USV position information for collision avoidance;the USV control system consists of an analogue converter,a voltage converter,a sixteen-way relay controller,a temperature and humidity sensor,a WFR09 S remote control module,an ESC rudder and a DC motor driver.Using an improved algorithm to process the images from the radar scan of obstacles near the USV,removing clutter and noise from the images,makes the marked obstacles clearer and more intuitive,and adds the function of extracting the maximum connected component in the algorithm,so that the improved algorithm can extract the maximum obstacle.The approach to collision avoidance for USV is based on the International Regulations for Preventing Collisions at Sea(COLREGS).This paper analyses the collision avoidance actions to be taken by USV in typical encounter situations by using the image information obtained from radar scanning of obstacles.There are three types of encounter situations between USV and obstacles: Head-on,Overtaking and Crossing.After the shore station computer has written the control program in the visual studio 2017 environment,it communicates with the USV through the radio digital transmission radio and controls the USV to perform various collision avoidance operations.The USV test platform was tested in the towing pool for straight navigation and steering,and finally the collision avoidance strategies for three typical encounter situations were tested and verified at the West Lake of South China University of Technology,and the motion trajectory of the USV could be plotted in the program interface according to the collected GPS data.The trajectory of the USV shows that the adopted collision avoidance strategy meets the requirements of the COLREGS and can achieve the basic needs of collision avoidance for USV,which has high engineering application value.