Structural Design And Research Of Vector Thruster For UUV Based On Spherical Parallel Mechanism

Since the 13th Five-Year Plan,the country has begun to vigorously develop the marine economy and enhance the strength of marine science and technology,and the demand for underwater vehicles has become increasingly urgent.For underwater vehicles,underwater propulsion technology is one of its key technologies.At present,the propulsion method of underwater vehicles mostly adopts the joint control method of multiple thrusters and the control method of single thruster plus rudder surface.The joint control method affects the shape of the underwater vehicle and increases its hydrodynamic resistance,while the control method of a single propeller plus a rudder surface is difficult to control the attitude and heading when the vehicle is sailing at low speed.Combined with the research background of the subject,it is necessary to design a vector thruster for the underwater vehicle,which can not only maintain the streamline shape of the underwater vehicle,but also make it easy to control the attitude during low-speed sailing,and at the same time meet the requirements of the underwater vehicle.The need for a quick dive.For small and medium underwater vehicles,a vector thruster in the form of a 3RRR spherical parallel mechanism is designed to realize the movement of the vehicle with multiple degrees of freedom.This paper firstly determines the design parameters of the thruster according to the subject background and functional requirements,and then analyzes and studies the overall structure and motion control system of the thruster,and designs the parts of each part.Combined with the force decomposition of the tail of the aircraft to determine the definition of the deflection angle of the parallel mechanism of the thruster,on this basis,the transformation matrix of the movable platform of the parallel mechanism is determined,and then the solution algorithm of the unique position inverse solution of the parallel mechanism is obtained.Then use the numerical iterative algorithm to solve,and determine the speed and acceleration mathematical model of the parallel mechanism.Use ADAMS and MATLAB to verify the above algorithms and models to determine the correctness of the algorithms and mathematical models.The condition number and maximum working space of the parallel mechanism are analyzed to verify the influence of the angle parameters and on the mechanism.Carry out resistance analysis and research on the aircraft.When the speed requirements of the aircraft are met,the thrust required by the propeller is determined.Based on this,the propeller of the propeller is designed using the atlas method,and the prop CAD is used to carry out 3D modeling of the propeller.Then use Fluent to verify the thrust provided by it.The dynamic simulation of the parallel mechanism is carried out by using ADAMS,and the torque required by the proximal link of the parallel mechanism is determined.The modal analysis of the parallel mechanism is carried out using Workbench to verify that the propeller speed will not cause the parallel mechanism to vibrate and cause excessive deformation.The motion control system of the underwater vector thruster is analyzed and researched,and the control hardware is selected and checked according to the load conditions and control requirements,the control system hardware is built,and the motion control program is written.Finally,an experimental platform is built to verify the correctness of the control program,measure the deflection angle error of the thruster movable platform,and determine the feasibility of the underwater vector thruster design scheme.