带缆遥控水下机器人水动力数学模型及其回转运动分析

摘要

提出了一种新型的带缆水下机器人系统三维水动力数学模型.在该模型中脐带缆的控制方程由脐带缆任一微段中的力的平衡条件导出,在此基础上以该脐带缆的控制方程为核心,通过引入脐带缆与水下机器人连接点的边界条件而建立起整个系统的三维水动力学数学模型.数值模拟中作用在机器人主体上的水动力载荷和旋转导管螺旋桨的控制力在考虑了它们之间的相互影响基础上以计算流体力学方法求出.该模型的主要特点是克服了现有的带缆水下机器人系统水动力数学模型将系统各组成部分割裂处理、缺乏从系统整体理论框架中去观察脐带缆、水下机器入主体和螺旋桨推进器水动力特征的缺陷,从一种综合、整体的观点去观察分析带缆遥控水下机器人的动力状态.水下机器人在导管螺旋桨作用下回转运动的数值模拟结果表明,利用所建立的数学模型可以对带缆水下机器入水动力状态进行有效的数值模拟.%A new three-dimensional hydrodynamic model to simulate the hydrodynamic behavior of a tethered underwater robot system is proposed. In the model the governing equations of umbilical cable are derived from the balance of forces at a point of the cable,these equations are taken as the core part for robot' s hydrodynamic model, the whole model can then be established by introducing the boundary conditions of the cable equations at the conjunction point between the lower end of cable and the underwater robot. In numerical simulation of this paper the hydrodynamic loading on main body of the robot and control forces issued from the running ducted thrusters are determined with computational fluid dynamics technique with their interactional effects being involved.The main characteristic of the model is that the model dynamic performance of tethered underwater robot system can be observed in a comprehensive point of view and some shortcomings in the existing hydrodynamic model can be overcome.These shortcomings include detached treatment to compositive portions of the robot system and insufficient investigation on the hydrodynamic performance of umbilical cable, robot main body and thrusters in an integral theoretical frame of the robot system.The numerical simulation of robot's turning motion under the effect of ducted thruster propul-sion indicates that the effective numerical simulation on the hydrodynamic behavior of tethered underwaterrobot can be conducted with the established model.