Research On Path Planning And Motion Control Of Underwater Optical Communication Robot

As the direct representative of modern intelligent robot,underwater robot plays the role of marine resources development,environmental monitoring and underwater reconnaissance for a long time,and is widely used in the extremely complex underwater environment.With the development of the research,the more complex and comprehensive task requirements make the underwater vehicle develop towards intelligence,specialization and networking.The topic "Research on path planning and motion control of underwater optical communication robot" is part of the project "Research on Key Technologies of reliable and flexible three-dimensional ocean observation and optical information communication network"(No:2019XD-A15).Aiming at the underwater optical communication robot in the project,this paper studies its intelligent and autonomous ability to reach the work site through the obstacle water area,namely,the research on path planning and motion control.In the aspect of path planning,the path planning and performance evaluation in complex environment are studied.In the aspect of motion control,the motion model,the key hydrodynamic parameters and the path tracking control strategy of underwater optical communication robot are studied.The specific research contents are as follows:(1)Complete the analysis and research of the movement model.The coordinate model was established using the system of the International Shipbuilding Association,and the equation of motion of the submarine optical communication robot was estimated.The external force of the environment to the robot was examined in more detail and a six degree dynamic range without a model was obtained,and the solution expression of the hydrodynamic term is given.(2)Numerical simulation methods are used to solve fluid parameters.Based on ANSYS(fluent)and XFlow software,the hydrodynamic performance of the robot under common working conditions is analyzed,and the inertial and viscous water resistance parameters are solved.Based on the existing research,the transient mechanical characteristics of straight line,rotation and acceleration are studied,and the accurate dynamic model parameters including added mass,viscosity parameters and inertia matrix are obtained.Not only the advantages of different software are considered,but also the typical transient parameters are solved.(3)Research on performance evaluation method of trajectory planning of underwater optical communication robot in complicated scenario.Analyze general operating conditions faced by underwater optical communication robot in complicated scenario,using the AHP as the basis for weighting,and proposes an improved cloud gravity center evaluation method.The energy cost function of bow rotation is introduced to improve the A*algorithm,and the path evaluation before and after the improvement of A*algorithm is carried out based on complex scenes.This method can provide guidance for planning the operation of underwater optical communication robots in complex scenarios.(4)The problem of path tracking(motion)control is studied.This article introduces the concept of task threshold and proposes improved line-of-sight guidance switching,compares several line-of-sight guidance processes.In addition,a QPSO algorithm with a backtracking effect has been proposed.This modifies the local attractor selection strategy and introduces it into the process of self-setting parameters for sliding mode control.Finally,the advantages of the proposed control strategy are verified by comparing with other control strategies based on MATLAB.(5)The scene simulation is run on the ROS system.The ocean environment is established by using the Gazebo.The simplified models of the propeller and the main device of the underwater optical communication robot are established by using the SolidWorks,and URDF file is exported to the Gazebo.The autonomous sending node control node of the target path point are established.The path track results are visualized in the RViz.Finally,the path tracking(moti control strategy proposed in the previous paper is verified.At the sai time,the performance of the control strategy under complex interferenc fault scenarios is compared and simulated.The results show that ti proposed control strategy has obvious advantages under complex workir conditions.