【作者】 崔峰；

【导师】 张明路；

【作者基本信息】 河北工业大学 ， 机械制造及其自动化， 2007， 博士

【摘要】 近年来,随着机器人、计算机、宇航等技术的飞速发展和交叉融合,机器人被越来越广泛的应用在对未知环境的探索工作中。要探测未知环境,机器人应具有自主导航、自主建立电子地图、传送地图的能力,如果要完成某些特定任务,机器人还应该具有遥操作的能力。经过多年的发展,机器人的地图自主创建和遥操作技术在国际上已取得了诸多成果,但是在这些成果中地图创建和遥操作往往是脱钩的,地图通常只具有显示功能,遥操作也大多是在远程视频的帮助下完成的,这就形成一个问题:操作员在遥控机器人的时候不知道此时机器人在地图中的具体位置,很难对机器人的运动有一个整体规划。本文在国家863计划项目“危险化学反应器控制与修补移动机械手系统(2003AA421040)”的支持下,对上述问题展开了深入研究,建立了一套面向虚拟现实和遥操作的移动机器人同步定位与地图创建系统方案,该方案能够以虚拟现实的方式对未知环境进行三维建模和立体图形交互显示,并以虚拟现实系统为遥操作终端以无线网络为传输媒介控制机器人的运行。充分发挥了虚拟现实的沉浸感和交互性,借助于立体显示设备,给操作员带来了身临其境的效果。本文的研究平台采用HEBUT-II型移动机器人,主要研究了三个问题:机器人的同步定位和三维地图自主生成;由三维地图到虚拟现实系统的构建;基于虚拟现实系统对机器人的遥操作。这三个问题紧密衔接在一起,从理论和实践上构造了一个机器人对未知环境的导航平台。论文的创新性工作如下:1.提出了机器人利用GPS和里程计进行粗略定位的具体方法,通过分析机器人的轮式结构建立机器人车体部分的运动控制命令模型。针对HEBUT-II型机器人的超声波传感器的位置分布和消除串扰回波问题,建立了超声波传感器的测量模型。在深入研究五自由度机械手的运动学问题的基础上,用D-H法建立了五自由度机械手运动学模型并分析了机械手的关节速度与雅可比矩阵。研制成功了机械手的控制系统。2.提出了一种以超声波传感器为探测手段的移动机器人自主建立三维电子地图的方案,深入研究了FastSLAM算法,利用粒子滤波和卡尔曼滤波确定各路标位置的误差椭圆。在此基础上,采用噪声模糊聚类的方法分段把误差椭圆的中心点进行曲线拟合,再以机械手末端执行器上安装的声纳测量环境中各路标高度,建立了环境的三维模型。3.建立了以虚拟现实系统为终端显示界面的具有立体显示功能和遥操作功能三维电子地图。该地图的几何模型来源于机器人建立的环境模型。研究了立体显示算法,并将其应用到电子地图中,通过立体显示外设,实现了具有沉浸感的场景再现功能。采用OBB (Oriented Bounding Boxes,有向包围盒)的碰撞检测算法提高了机器人的安全性。以数据手套作为人机交互设备,设计了用于机器人遥操作的手势集合,实现了地图中的虚拟机器人和真实机器人的同步运动,整个交互过程直观、自然,符合人在自然环境中的表达方式。4.提出了基于WLAN和基于GPRS的两套独立运行的无线通信方法,分别负责传送地图模型信息、遥操作命令和远程视频。WLAN作为主要的传输方式,采用了BSS的拓扑结构连接,通过增加高增益天线改善了普通的WLAN通信距离短的缺点,把通信距离成功拓展到数公里之外。针对视频传输对带宽要求较大的问题,研究并设计了多线程的传输方式,进一步提高了传输速率。GPRS作为辅助方式,以AT命令的方式发送指令遥控机器人运行,或启动机器人控制器来完成建图或者遥操作工作。5.本文分别在操场、办公室、走廊等环境进行了一系列地图自主创建实验。实验表明机器人能够实时地完成三维模型的创建并具有较高的精度,所生成的地图能够给操作员带来很好的沉浸感。更多还原

【Abstract】 With the rapid development of the robot, computer and space navigation technology and syncretization between them these years, the robot is applied more and more widely in the exploration of the unknown environment. To explore the unknown environment, the robot should have the ability of self-navigation, self-electronic map production and transmission. Furthermore, to complete some special assignment, the robot should be under the teleoperation. In decade years, there has been much harvest in the field of robot self-electronic map production and teleoperation throughout the world. While the self-electronic map production and teleoperation are separated in these results, that is, the map only can been displayed, and the teleoperation mostly need been carried out by the remote video. Then the problem appears that the operator doesn’t know the position of the robot when telecontrols it, so it is difficult to get a whole plan of the robot movement.Supported by Hi-tech Research and Development Program of China (No. 2003AA421040), the author has done deep research on the above problem in this essay. It established a mobile robot simultaneous localization and map building system to virtual reality and teleoperation, which can build 3D model and display the solid graphics, and control the robot by the wireless LAN with virtual reality system. In the meantime, the system make the operator feel in the real environment based on the character of the virtual reality.Exploring the environment by ultrasonic sensors, the essay researched the HEBUT-II mobile robot, and stated three points as follows: the simultaneous localization of the robot and the autonomously builded 3D map, from the 3D map to establishing the virtual reality system, teleoperation of the robot based on the virtual reality system.The essay’s content as follows:1. Set up the localization method of the robot by the GPS and milemeter, built the movement control model of the robot bodywork through analyzing the robot wheel structure. Established the measure model of ultrasonic sensors according to the ultrasonic sensors position and the crosstalk problem of the HEBUT-II robot. Established the kinematics model of 5DOF manipulator by D-H method, then analyzed joint velocity of the manipulator and Jacobian matrix. Designed the control system of the manipulator.2. Put forward the scheme of building 3D electronic map by the robot independently with ultrasonic sensors, lucubrated the FastSLAM algorithm, ensured the error ellipse of landmark position by particle filter and extended Kalman filter, and based on which, got the planar profile of the environment by merging the error filters center points to curve by adaptive fuzzy clustering algorithm integrated with noise clustering technique. Measured the landmark height by the sonar on manipulator end- effector after establish 2D model. Obtained the 3D model by connecting the scale of the landmark height with the planar model.3. Building the 3D electronic map with stereo display and teleoperation, whose vision interface was virtual reality system. The map’s geometry model was from the 3D model. Made the electronic map being provided with stereo display ability through researching on stereo display algorithm and applying it. Realized the scene emersion function with immersion by connecting stereo display facilities. Strengthened the safety by the OBB (Oriented Bounding Boxes) collision detection. Used the data gloves as the interaction machine of the person and the robot, also designed gesture aggregate for robot teleoperation. The virtual robot in the map and the real robot moved simultaneously, which the whole process was natural and direct according with the expression ways of the human in the environment.4. Established two separated telecommunication systems based on WLAN and GRPS, which transmit the message of map model, teleoperation order and long-distance video. As the main transmit method, WLAN connected by BSS topology structure. Extended the communication distance by using high gain antenna. Improved the transmit speed by studying and designing the multithread transmit way according to high bandwidth requirement of video transmit. As the assistant way of GPRS, telecontrolled the robot by AT order, or set up the map and teleoperated by startuping the programming in the robot computer.5. In the essay, experiments about the HEBUT-II robot autonomously building the map had been done on the playground, office and aisle. In these experiments, the robot could establish the 3D model which has higher precision in time basically, and the map can bring the immersion to the operator.更多还原