Body Design And Research On Motion Control Of 500 Meter Remotely Operated Vehicle(ROV)

Remotely operated vehicle(ROV)has the characteristics of long underwater operation time and diverse functions,and has become a widely used underwater vehicle in the field of ocean engineering.The domestically independently developed working-level ROV has not been well matching with industrial demand,so the design and development of ROV has practical significance.As the motion of underwater operating ROV is characterized by nonlinear and strong coupling as well as environmental interference,ROV operating path control needs to be focused on.The main research work of this paper includes:(1)According to the engineering requirements of crack detection and damage repair for the underwater part of large offshore structures,a kind of 500-meter working-level ROV was designed.Based on the design index of the project,the key modules of the underwater robot was designed with modular method,by reference to the type design and material selection of domestic and foreign products.Three-dimensional modeling software Solid Works was used to complete the body design and virtual assembly of the ROV.The structure strength requirements were verified by finite element analysis of the body frame structure,and the center of buoyency and gravity of the ROV were calculated and adjusted.(2)Carry out a series of hydrodynamic performance studies for the body design scheme.The six degrees of freedom mathematical model of ROV nonlinear system was established,including kinematics and dynamics equations.Based on the assumption of rigid body motion,the hydrodynamic performance in steady and unsteady states was studied in detail by CFD method.The No.19 A duct and Ka series propeller in the ducted propeller atlas were selected according to the obtained water resistance,and the open-water performance of the ducted propeller was studied.The reliability of the numerical method was verified by comparing the numerical simulation results with the data of the reference atlas.(3)Motion control prediction of ROV was carried out for application scenarios of jacket platform detection.The hydrodynamic coefficients obtained by numerical simulation were used to carry out ROV motion control design in horizontal plane.The path tracking model based on virtual wizard was obtained.The control principle of backstepping method was adopted to build kinematics and dynamics control modules in Matlab/Simulink.The path tracking simulation example of horizontal plane trajectory was realized,which provides a basis for further study of complex operation path planning.