Research On Kinematic Performance And Multi-Objective Optimization Of Spherical Parallel Vectored Thruster For Underwater Vehicle

As a new technology,underwater vector propulsion technology can achieve the multi-gesture underwater propulsion with single machine,which simplify the structure of underwater robot,and have the characteristics of large rigidity,large bearing capacity and high reliability.In recent years,more and more attention has been paid to it.It has become a hot and frontier technology of underwater robot research,and it is important that the application prospect and application value.In this paper,2RPC&2RPCU vector propulsion parallel mechanism is taken as the research object.1.The coordinate system of the 2-RPC&2RPCU vector propelled spherical parallel mechanism is established.In addition to the positive and negative solutions of the two DOF vector propelled spherical parallel mechanism,the Jacobian matrix of the mechanism is obtained,and the positive and inverse solution of the mechanism is obtained by using the method of motion helix on the basis of the positional positive inverse solution.2.The three performance evaluation indexes of the 2-RPC&2RPCU vector propelled spherical parallel mechanism are established.With the help of the positive and negative solution model of the mechanism position,the motion space simulation of the mechanism is calculated by MATLAB,and the dexterity of the mechanism based on the Jacobian matrix is established.According to the evaluation index,the corresponding performance map is made in the design space,and the traditional stiffness evaluation index of the mechanism is set up.The overall stiffness performance atlas of the mechanism and three different directions of the stiffness performance atlas are made.3.Combining the three performance evaluation indexes,the multi-objective optimization model of the mechanism is established.Under the constraints of various conditions,the multi-objective optimization based on genetic algorithm is carried out.The optimal value of the related parameters is obtained,and the performance index atlas before and after the optimization is simulated and compared.4.With the help of the finite element simulation software Ansys,the static analysis of the 2-RPC&2RPCU vector propelled spherical parallel mechanism under three special gestures is carried out.The overall deformation analysis and stress conditions under three different attitudes of the mechanism and the maximum force point and shape analysis in the three directions are obtained,and the six order modal points for the mechanism are divided.The vibration frequency of each order of the mechanism is obtained.5.The 2-RPC&2RPCU vector propulsion spherical parallel mechanism is carried to the subject of the underwater robot designed by the project group.The whole platform of the underwater robot is constructed,and the experiment of the attitude transformation of the water pool is carried out.The directional navigation,the rotary test and the predetermined line control test are carried out.The experiments show that the underwater robot has the characteristics of good flexibility and stability.