Conceptual Design, Kinematics and Dynamics of Vector Thruster for Underwater Vehicle Based on Screw Theory

The vector propulsion device can significantly improve the sensitivity and mobility of the mechanism. Furthermore, thrust vectoring technology with single manipulator and multidimensional attitude is a novel thrust vectoring technique in industry, especially in aviation fields. Numerous progresses made by various research groups and the newest patents in these aspects will be cited in this paper. To apply the thrust vectoring technology to Autonomous Underwater Vehicles (AUVs), a spherical parallel vectored thruster with three Degree-Of-Freedom (DOF) was proposed based on vector deflection constrained screw method. Firstly, in the framework of screw theory, the topological structure of the spherical parallel mechanism was modeled to analyze the motion characteristics. Secondly, in terms of closed chain constraint equations, the vectored algebra method was employed to derive the Jacobian matrix of the mechanism. Thirdly, the decoupling structure configuration method was adopted to establish the analytical model of velocity and acceleration. Finally, the dynamic model was established by means of virtual work principle. The forward and inverse solutions of the mechanism was calculated; the Jacobian matrix of the mechanism was derived; the kinematic characters including singularity and dexterity were analyzed; the performance analysis was carried out. This new type of underwater vehicle oriented power plant, which is characterized by simple decoupling structure, strong steering capability, and high cost-efficiency, has broad prospects in the field of AUV.