Nonlinear pitch control of an underwater glider based on adaptive backstepping approach

Underwater gliders are highly efficient and long-ranged autonomous underwater vehicles. The typical dynamic modeling in the vertical plane is of multi-input multi-output(MIMO), which is underactuated while easily affected by the ambient environment. To resolve the problems of MIMO, the dynamic model is transformed into a single-input single-output(SISO) system with two dubious parameters, and an adaptive backstepping controller is designed and applied in this paper. A Lyapunov function has been established with the total energy of the system converged in the controller. Contrast result of simulation has demonstrated that the derived nonlinear controller has higher tracking precision and faster response than the proportional-integral-derivative(PID) control method,which indicates its excellent capability to deal with the controlling problems of underwater gliders.     

潜水器控制系统基于模型故障诊断技术研究

在分析了前人故障诊断技术研究成果和潜水器控制系统结构的基础上,按照结构、功能和组件包含关系,为潜水器控制系统进行故障诊断建模。依据基于模型故障诊断技术,建立了适用于潜水器控制系统故障诊断的具体诊断和推理策略;最后给出了包含整个诊断过程的诊断实例。     

基于OpenGL的深海开架式潜水器视景仿真设计

采用虚拟仿真技术,以正在研发的深海开架式潜水器的设计尺寸和数字海底理论为基础,采用基于面向对象数据模型和基于表面三角剖分的方法来构建水下目标的三维空间数据模型。以三角形的空间拓扑关系为基础,利用SolidWorks建模工具和VC++OpenGL图形开发库,实现了深海虚拟环境下的系统仿真。通过水下目标的建模实例,验证了仿真平台的正确性和可行性,该平台还可应用于深海综合调查研究、水下机器人操纵运动控制仿真等领域。     

Research on the performance of passive heave compensator for tethered remotely operated vehicle system

A passive heave compensator is designed to enhance the operation safety of a 4.5 km remotely operated vehicle (ROV). This paper proposes a novel idea of designing a compensator with relatively low natural period to optimize gas volume and while adding a special device to remove the problem of ineffectiveness and resonance in long seas. Numerical simulations are done based on serious dynamic model of the whole system, including the compensator, the umbilical tether and the vehicle, solved by the fourth-order Runge-Kutta scheme. The compensator provides great attenuation of motion and tension in most sea states. As the working depth increases, the system natural period decreases, resulting in the occurrence of risk of resonance. By regulating the system damping, the compensator can be effective in these situations.     

"海龙-3500"深海潜水器的变长缆运动建模与仿真

仿真并分析了“海龙-3500”深海潜水器(ROV)出中继器后的运动过程。考虑海流的影响,ROV的建模采用通用的动力学模型,轻缆的建模采用凝聚参数法。结果表明,设定的放缆方案是合理的,可作实际操作参考。提供的缆和ROV系统的仿真算法,可用作实际操作前的模拟计算。     

基于模糊PID方法的ROV操纵控制仿真

为应对复杂的作业工况和海洋环境,研究了水下中型作业遥控机器人(ROV)的操纵控制运动.文章分析了作业型ROV的操纵特性,根据其基本的定向、定高和定深的航行能力需求,基于模糊PID方法的控制原理,为其配置了精度高、响应快的控制系统,建立了4自由度操纵控制运动模型,对定向、定高等运动性能的操纵进行仿真研究,通过水池实验验证了该控制方法的有效性.     

Direct algorithms for steady-state solution of long slender marine structures

The steady state solution of long slender marine structures simply indicates the steady motion response to the excitation at top of the structure.It is very crucial especially for deep towing systems to find out how the towed body and towing cable work under certain towing speed.This paper has presented a direct algorithm using Runge-Kutta method for steady-state solution of long slender cylindrical structures and compared to the time iteration calculation;the direct algorithm spends much less time than the time-iteration scheme.Therefore, the direct algorithm proposed in this paper is quite efficient in providing credible reference for marine engineering applications.     

水下滑翔机附加质量数值计算

水下滑翔机的附加质量对其运动状态影响较大,本文采用了Hess-Smith（面元法）方法编制了计算任意三维物体附加质量的程序,利用Gambit软件对水下滑翔机进行网格划分,计算出实验室所研制的水下滑翔机附加质量,同时利用CFD（Computational Fluid Dynamics）技术,结合动网格技术和UDF（User-Defined Function）,对水下滑翔机进行了PMM（Planar Motion Mechanism）试验模拟,并与Hess-Smith方法得到的结果进行对比,分析两者之间的特点和各自优势。