【作者】 李睿；

【导师】 袁楚明； 严思杰；

【作者基本信息】 华中科技大学 ， 机械工程， 2021， 硕士

【摘要】 电力企业需要定期对发电机进行检修以掌握其长期运行后的膛内状况。传统的人工检修方法需要抽出发电机转子,存在检测效率低、劳动强度大和安全隐患高等缺陷。为解决这一问题,能够在不抽离转子的情况下进入发电机膛内开展检测作业的爬壁机器人正逐步得到应用。目前,国产的发电机检测机器人尚处于测试阶段,样机均采用爬行于定子的方式,而由于部分型号发电机的定子内壁存在挡风板,极大地限制了该类机器人的检测范围,因此其通用性存在明显不足,为此本文设计了一种基于转子爬壁机器人的发电机智能检测方案,借助爬壁机器人搭载的各类检测设备完成检测任务,主要工作内容如下:根据检测任务的需求与发电机膛内工作环境,分析检测机器人的技术指标,从而选定机器人吸附、移动和驱动方式,同时确定机器人应搭载的检测设备。基于上述硬件选型分析控制模块的功能需求,得出其硬件部分和软件部分的总体框架。控制模块硬件部分基于模块化设计思想,划分为四个功能单元,完成各单元电器元件的选型和接口电路的设计,最终得到了基于STM32的硬件原理图及PCB设计。控制模块软件部分基于嵌入式实时操作系统u C/OS-II设计,首先,移植u C/OS-II到控制板上,并根据板载硬件资源设计开发BSP;然后,根据检测需求设计了各项控制任务,通过调用操作系统和BSP提供的硬件访问接口实现控制功能。此设计路线相较于裸机开发具有更高的稳定性和实时性。由于发电机膛内空间狭小,本设计中选用微型USB摄像头完成膛内视觉检测任务。受限于USB数据线的传输距离,需要对视频传输方式进行转换,因此设计了一套基于ARM Cortex-A9的嵌入式视频服务器,能够将多路USB视频流转换为网络视频流。通过修改开源服务器Mjpg-streamer中子程序的方式,使得服务器能利用微处理器对USB摄像头采集的视频进行硬件编码,从而显著降低视频传输所需的带宽。通过HTTP协议将视频数据发送到局域网内,可实现多个设备同时查看实时视频的功能。最后,分别搭建测试平台,对控制模块与多路视频传输模块分别进行了测试,测试结果显示控制模块正确运行,视频传输模块能够降低8倍网络传输带宽,证明了二者均符合设计需求。更多还原

【Abstract】 Electric power companies need to regularly overhaul the generators to understand the conditions in the chamber after long-term operation.The traditional manual maintenance method needs to extract the generator rotor,which has the disadvantages of low detection efficiency,high labor intensity and high potential safety hazards.In order to solve this problem,wall-climbing robots that can enter the generator bore to carry out inspection tasks without pulling away the rotor are gradually being used.At present,domestic generator detection robots are still in the testing stage.The prototypes all use the method of crawling on the stator.However,due to the presence of wind deflectors on the inner wall of the stator of some types of generators,the detection range of this type of robot is greatly limited,so it is universal There are obvious shortcomings in performance.For this reason,this paper designs a generator intelligent detection scheme based on a rotor wall-climbing robot.The detection task is completed with the help of various detection equipment carried by the wallclimbing robot.The main contents are as follows:According to the needs of the inspection task and the working environment in the generator bore,the technical indicators of the inspection robot are analyzed and tested,so as to select the robot’s adsorption,movement and driving methods,and at the same time determine the inspection equipment that the robot should carry.Based on the abovementioned hardware selection and analysis of the functional requirements of the control module,the overall framework of its hardware part and software part is obtained.The hardware part of the control module is divided into four functional units based on the idea of modular design.The selection of the electrical components of each unit and the design of the interface circuit are completed,and finally the hardware schematic and PCB design based on STM32 are obtained.The software part of the control module is designed based on the embedded real-time operating system u C/OS-II.First,transplant u C/OS-II to the control board,and design and develop the BSP according to the on-board hardware resources;then,various controls are designed according to the testing requirements Task,realize the control function by calling the hardware access interface provided by the operating system and BSP.Compared with bare metal development,this design route has higher stability and real-time performance.Due to the narrow space in the generator bore,a micro USB camera is used in this design to complete the task of visual inspection in the bore.Limited by the transmission distance of the USB data cable,the video transmission method needs to be converted,so a set of embedded video server based on ARM Cortex-A9 is designed,which can convert multiple USB video streams into network video streams.By modifying the subroutine of the open source server Mjpg-streamer,the server can use the microprocessor to perform hardware encoding on the video collected by the USB camera,thereby significantly reducing the bandwidth required for video transmission.The video data is sent to the local area network through the HTTP protocol,which enables multiple devices to view real-time video at the same time.Finally,the test platform was built separately,and the control module and the multichannel video transmission module were tested separately.The test results showed that the control module was operating correctly.The video transmission module can reduce the network transmission bandwidth by 8 times,which proves that both meet the design requirements.更多还原