【作者】 郭莹；

【导师】 赵耀； 徐国华；

【作者基本信息】 华中科技大学 ， 轮机工程， 2008， 博士

【摘要】 随着地球上资源枯竭问题的严重,海洋开发越来越受重视。但是海洋条件恶劣,使用水下机器人和作业机械手已成为海洋开发的重要手段,代替人类去观测海洋、调查海底地质和采掘资源。在水下智能机器人上装配作业机械手,构成水下自主作业系统是水下智能机器人发展的一个重要方向。水下自主作业系统能够同时控制水下机械手终端位置和作用力,从而可以克服主/从配置的机械手系统的轨迹跟踪精度低、难于实现精确力控制、运行费用高昂及操作易疲劳等缺点,它将在各种浅海和深海使命诸如海洋科学、油气探测、水下考察、钻井及采矿支持、管道维护、水下电缆铺设及军事应用中发挥非常重要的作用。水下自主作业系统具有强耦合、非线性、高维数、时变等特点。实现水下自主作业涉及到诸多问题,其中作业时,水下机器人和水下机械手之间的协调控制技术是有待解决的关键性技术之一,本文针对这一问题,展开研究。本文首先分别讨论了水下智能机器人和水下作业机械手的运动学和动力学模型。通过分析水下机器人和机械手在水中的运动情况,根据动量定理和动量矩定理得出其空间运动方程;分析其在水中作业时的受力情况,得出动力学方程。为之后建立系统整体模型奠定了基础。在考虑了各种水动力影响因素的基础上,使用Quasi-Lagrange方程建立自主水下作业系统的动力学数学模型,并将此模型分解为一系列相互关联的子系统;研究PID控制和滑模控制算法,设计PID控制器和滑模控制器用于水下自主作业系统协调控制,并使用模糊逻辑动态调节控制器的控制参数。为了验证模型及控制算法的有效性,在某型水下机器人平台上分别装具三功能(二自由度)和五功能(四自由度)作业机械手,考虑静水和匀速平流两种环境,进行仿真研究,通过仿真结果分析、对比,得出滑模控制表现出比PID控制更好的控制精度和稳定性;五功能机械手比三功能机械手对机器人平台的耦合影响更大。为了更好地研究水下自主作业系统的协调控制技术,对一个小型开架式遥控水下机器人进行改造,将其改造成为一个遥控/智能机器人。并在机器人平台上装具一个三功能机械手,建立水下自主作业试验系统用于试验研究,并对该系统进行了一系列相关试验。本文结合相关研究项目,对水下自主作业系统的协调控制问题开展了一系列的研究工作,其研究成果为水下自主作业提供了理论依据和技术手段。其中,许多工作有待开展进一步的研究。更多还原

【Abstract】 Ocean covers a large of the earth, which is relatively less explored. With the energy on earth is consumed up, the development of ocean is more and more important. The underwater vehicles and the robotic manipulators are effective tools to help people to see and touch this unfamiliar word. Robotic manipulator, mounted on the autonomous underwater vehicle(AUV), is usually called Underwater Vehicle-Manipulator System(UVMS). Currently, the master-slave configuration of underwater manipulation system is widely used. This kind of configuration has many disadvantages, such as, low accuracy of trajectory tracking, difficulty to realize accreted force control, high operational cost and operator’s fatigue to name a few. To overcome these deficiencies, an autonomous manipulator control system that could simultaneously control the position of the end-effector and the force applied to the environment would be better solution. Thus, the UVMS has an important role to play in a number of shallow and deep sea missions for marine science, oil and gas searching, underwater inspection, drilling, mining, pipe-line, maintenance underwater cable burial and military application and so on.The character of the UVMS is nonlinear, coupled, time-varying and high-dimension. The implementation of the self-manipulation under water depends on various kinds of pivotal technology. The important one of them is the coordinated control of the AUV and manipulator. It was presented the coordinated control of UVMS in this dissertation.Firstly, the kimematic and dynamic equations of the AUV and the manipulator are discussed in this dissertation. Based on the motion in water of the AUV and the manipulator, the kinematic equation is got from the momentum theorem and the angular momentum theorem. We have developd the dynamic equation, based on the analysis of the hydrodynamic force.A dynamic model for the UVMS considering various hydrodynamic effects is derived using Quasi-Langrange method. And, the PID and sliding mode controllers are designed based on the decentralized form of the dynamics of UVMS, to implement the control of the end-effector trajectory tracking. Due to ensure the better control performance, the gains of the two controllers are tuned with the fuzzy logic.In order to validate the accuracy of the model and the effectiveness of the controllers, computer simulations using two UVMSs, a two degrees-of-freedom(DOF) manipulator and a four DOF manipulator separately mounted on an AUV, were performed in the environments of the slack flow and const laminar flow. The simulation results show that the sliding mode control, in contrast with the PID control, provides more accurate and robust performance, and the four DOF manipulator, in contrast with the two DOF manipulator, has the more coupled interaction with the AUV.An experiment system, composed of an UVMS and a computer controller, is founded to research the coordinated control. The UVMS is composed of a remotely operated underwater vehicle and a manipulator. The control of the vehicle is altered from the remotely operated control to the autonomous control. Some experiments were implemented to get the hydrodynamic coefficients of the vehicle, for the dynamic model.Based on the related projects, a series of research about the coordinated control of UVMS is performed in this dissertation. The results will give substantial support on theory and technique for control of UVMS. However this is just first step and more research work is required in future.更多还原