Design And Implementation Of Underwater Video Acquisition System For Sea Cucumber Culture

In recent years,sea cucumber aquaculture has become an important part of the aquaculture industry.However,a large number of deaths often occur during the sea cucumber farming process,so it is necessary to observe the growth status of sea cucumbers regularly.Currently,underwater video images are mainly extracted by divers holding cameras.This method has limitations such as poor video quality and safety hazards.In this paper,a set of underwater video collection system was designed based on Remotely Operated Vehicle(ROV),which is easy to operate,stable and has the function of underwater observation.The performance and advantages of the system were verified through experiments.This research provides an efficient,safe and low-cost underwater video collection technology for sea cucumber farming,which helps to improve the development level of sea cucumber farming industry.The main research contents of this paper are as follows:(1)A hardware system for a micro ROV aimed at sea cucumber farming was designed.Firstly,according to the design requirements of the farming scene,the overall functions and design indicators of the robot were analyzed.Secondly,the hardware system of the robot was designed,including carrier frame and control cabin,and the strength analysis verification of each component was carried out.Finally,the motion control system of the robot was designed to realize the motion control of six degrees of freedom of the robot.The micro ROV has the characteristics of low cost,small volume,strong operability and high safety,which can meet the needs of sea cucumber farming scene and lay a foundation for subsequent functional design of underwater video collection system.(2)A control method for fixed depth,direction and height based on Phased Integral Separation PID(ISPID)algorithm and autonomous area coverage search method were proposed.Firstly,aiming at the problem that traditional PID control algorithm is prone to large overshoot in control process,ISPID control algorithm was used to design fixed depth,direction and height functions of ROV.Secondly,based on this,aiming at the demand for collecting large area underwater videos,ROV’s search path was planned and autonomous area coverage search method was designed.Experimental results show that ISPID-based control method can effectively reduce system overshoot and response time,improve system stability and underwater observation effect.The autonomous area coverage search method can effectively improve robot autonomy,reduce personnel participation degree and improve work efficiency.(3)The application program design of underwater video collection system was completed.Firstly,using Robot Operating System(ROS),perception module and execution module of robot were designed to construct framework of video collection system with low coupling between modules and high stability of system.Then video collection module was designed to extract underwater video images.Finally,through graphical user interface application program pyqt5 design visual operation interface of system simplified system operation and realized good human-computer interaction.Through practical cases,the effectiveness of the system has been verified.The system has been applied to actual underwater observation work in sea cucumber farming many times.