Design Of Body And Research On Motion Control Of A Mini Underwater Vehicle

Due to the needs of marine environmental monitoring,exp loration and development of seabed resources and military applications,the underwater vehicle technology has made great progress and a variety of underwater vehicles that can be used in different environments and different tasks are developed.Among them,mini underwater vehicles with excellent portability have gained wider attention because of their more convenient use and more flexible operation.Mini underwater vehicles have broad application prospects in underwater observation,archaeology,search and rescue,aquaculture,etc.,which can replace human beings in observation,imaging and information collection in deep water environment.In this paper,the mini remote operated vehicle is taken as the research object.According to the design index,the design of a mini underwater vehicle with 5 degrees of freedom is completed.The structural form,material,sealing method,and propulsion mode of the underwater vehicle are determined.The thrust distribution calculation is focused on,and the circular vector arrangement of propellers is determined based on the requirements of flexibility and practicability.The center of mass and buoyancy of the underwater vehicle are calculated,and the design of the control system is completed.The propeller used in the mini underwater vehicle is designed by the propeller design chart.Firstly,the two-dimensional coordinates of the blade section of the propeller are calculated based on the design chart data;Then,the three-dimensional coordinates of the propeller data points are obtained by the conversion formula;Finally,the coordinates are imported into the 3D modeling software to generate the propeller model.Next,the difference of open water performance between the hub-type and hubless propeller is studied by numerical simulation method,and the simulation results of the two propellers are compared and analyzed.The results show that the hydrodynamic performance of the hubless propeller is better than that of the hub-type propeller.The kinematics and dynamics model of the mini underwater vehicle is established.The viscous hydrodynamic and inertial hydrodynamic forces of the underwater vehicle are simulated and the main hydrodynamic coefficients of the underwater vehicle are obtained,thus further improving the equation of motion.The PID controller of the underwater vehicle's depth control is designed and the depth control simulation is carried out.The simulation results show that the PID control algorithm can effectively control the depth motion of the underwater vehicle.Finally,underwater vehicle depth control experiments are carried out in pools and lakes.The mini underwater vehicle can complete the deep motion with reasonable accuracy is proved by the simulation results and experimental data.