Modular Underwater Robot Design And Mechanical Analysis

Remotely operated vehicle(ROV)has very broad prospects in underwater exploration,aquaculture,and underwater salvage.The research and development of shallow-water observation ROV has the potential for aquaculture,equipment testing,and resource exploration in shallow waters in China.Very important significance.This project is based on the “Key Technology and Application of Underwater Binocular Vision Robots” of the Shaanxi Provincial Science and Technology Coordination and Innovation Project.The purpose is to design and develop a small modular ROV system with independent intellectual property rights for use in shallow waters for aquaculture and underwater exploration.In this paper,based on the research of the existing frame-shape ROV,a frame-shape shallow water observation level ROV is designed according to factors such as design indicators and work environment.1.Completed the overall design of the frame-shape underwater robot.It is determined that the ROV system is composed of watertight pressure-resistant cabins,power propulsion modules,power supply modules,observation and lighting modules,counterweight and buoyancy modules,carrier frames and auxiliary accessories.The watertight and pressure-resistant cabin is mainly used to provide an underwater sealed working environment for non-pressure and non-water resistant components such as electronic communication equipment,detection instruments and sensors;the power propulsion module is divided into four propeller propellers,they cooperation with each other to ensure that the underwater robot can meet the four directions of movement: advancing and retreating/ yawing/ snorkeling/ rolling in water;the power supply module provides power for the small shallow water observation level ROV;the observation and lighting module obtains underwater image information through the camera;the weight and buoyancy modules are used to ensure the balance of buoyancy and gravity of underwater robots;the carrier frame is used to carry power propulsion modules,power supply modules,and sealed electronic cabins;auxiliary accessories are to supplement and optimize the entire system.2.Completed the ROV's ontology structure design.Determine the specific structural types of each major functional module,including the design of watertight pressure shells,power system and power supply design,observation and lighting system design,underwater seal design,overall balance design,and structural material selection.The pressure electronic chamber and battery compartment were designed in detail.The overall assembly and structural optimization of the ROV were completed using Solid Works software.Through the mutual verification of the theoretical calculation and static analysis,the strength verification of the key parts of the ROV was completed.This combination of methods proves that both the selected materials and the designed structure meet the requirements for strength and reliability.3.Kinematics and dynamics analysis of the designed ROV system.The conversion relationship of the ROV system's spatial motion in the fixed coordinate system and the motion coordinate system is introduced.The parameters that need to be considered in ROV modeling are analyzed from the perspective of kinematics and dynamics,and the mathematical model of ROV kinematics and dynamics is established.Based on the theoretical calculations,the hydrodynamic simulation of the designed ROV was performed using Fluent software.After 133 iterations,the residual monitoring curve,lift,and drag coefficient curves converged.The simulation results obtained the resistance of the ROV forward process and the pressure cloud diagram of the ROV model.Through simulation analysis of hydrodynamics,the simulation results show that the simulated values of underwater resistance during simulation of underwater advancing ROV are in accordance with the theoretical calculations,which proves that the theoretical model is correct;the resistance and pressure are within the normal range,which proves that the design of ROV structure designed in this paper.And the power layout is reasonable.