Control of the Position of an Underwate Towed Robot

1)开发了一个海洋中复杂流场作用下柔性长缆三维运动的数值模拟程序，该程序可以准确地模拟柔性长缆的非线性运动。2）建立了一种研究船舶-柔性长缆-水下拖曳体（机器人）系统动力稳定性的理论。在假定缆索的横向挠度和张力沿缆索沿着缓慢变化的条件下，用WKB方法求解缆索的振动方程，研究了机器人在操纵面作用下的稳定性。3）模拟了主要由海洋内波引起的所谓统计波动，并开发了一个仿真程序，其中应该通过操纵拖船将水下机器人引导到指定位置。该模拟程序包含了本项目中得到的所有结果。仿真结果表明，在复杂的海洋环境中，要实现机器人的精确导引，需要更先进的船舶控制技术。4）研究了拖曳机器人末端控制理论，为拖曳船舶的操纵提供了理论依据。

1) A simulation program was developed of three-dimensional behavior of a long flexible cable under the influence of complex flow in the ocean, by which nonlinear behaviors can be accurately simulated. We confirmed a good agreement exists between computations and experiments.2) A theory for investigating the dynamic stability of a system composed of ship, long flexible cable, and underwater towed vehicle (robot) was developed. Under the assumption that the transverse deflection and tension are slowly varying along the cable, an equation of the vibration of cable was solved with WKB method, and the stability of a robot to the action of a control surface was investigated.3) We simulated the so-called statistical fluctuation due mainly to the internal waves in the ocean, and developed a simulation program in which an underwater robot is supposed to be guided to a specified position by maneuvering a towing ship. This simulation program involves all the results obtained in this project. Simulation results revealed that more advarfced ship control is necessary for a more accurate guidance of a robot, especially when the ocean flow is complicated.4) A theory of end-point control was investigated for the perfect guidance of a towed robot to a specified position, which can be used for the improvement in how to maneuver a towing ship.