管道环焊缝TOFD检测自动扫查系统设计

发布时间：2018-07-07 18:03

本文选题：管道环焊缝 + TOFD检测　；参考：《兰州理工大学》2017年硕士论文

【摘要】：管道被誉为现代工业和人民生活的大动脉,对保卫国家能源安全、保障经济建设和居民生活具有重要意义。在安装和焊接过程中由于人为因素的影响或者在运行过程中受到介质、压力等因素的影响,管道最脆弱的地方——“对接环焊缝”可能出现不同程度的缺陷,从而影响管道的安全运行。为了保障在役管线能够安全、有效、稳定地运行,必须定期进行无损检测。传统的手动无损检测在过去一直是工业管道定期检验的主要手段;随着工业自动化水平的提高,自动化无损检测成为一个研究热点。在众多的无损检测中,超声检测因其自身特性而成为自动化无损检测采用的主要技术;自动化超声检测具有检测效率高、扫查重复性好等特点,越来越受到青睐。本文依托中国特种设备检测研究院的工程应用类研究项目“反馈式管道自动扫查装置研制”,以衍射时差法(TOFD)超声检测为技术手段,设计自动扫查器,通过扫查器搭载TOFD探头对在役管道环焊缝进行自动化TOFD检测研究。主要研究工作如下:(1)分析了国内外管道环焊缝自动扫查系统的研究现状;比较了几类结构的自动扫查器的优缺点,并针对现有的自动扫查器结构复杂、体积较大且运动不灵活等缺点,提出设计一款更灵活、方便、小巧的自动扫查器。本扫查器采用磁轮吸附式小车结构,与现有的自动扫查器相比,增加了CCD循迹功能,以实现自动纠偏;同时,采用无线控制,便于操作。(2)完成了对整个扫查器机械结构及其关键部件的设计。(3)通过对主控制器模块、CCD采集模块、电机驱动模块、无线遥控模块和电源转换等模块的设计完成了电路原理图;最后制作了PCB板、焊接了相关元器件,完成了整个硬件电路系统的设计与制作。(4)规划了扫查器的控制流程,分别采用黑线提取算法和PID控制算法,通过编程完成CCD循迹控制和PWM电机控制;建立了电机模型,对电机性能进行仿真;在Matlab中建立了控制系统的Simulink模型,对整个控制系统进行仿真,得到的系统仿真响应曲线满足响应时间快,运行稳定等要求。(5)分别在实验室环境和工业现场进行试验,验证了自动扫查器的运行指标满足工业现场检测的要求。
[Abstract]:Pipeline is regarded as the artery of modern industry and people's life. It is of great significance to safeguard national energy security, economic construction and residents' life. Due to the influence of human factors during installation and welding, or due to the influence of medium, pressure and other factors during operation, the most vulnerable place of pipeline-"butt girth weld", may be defective to varying degrees, Thus affecting the safe operation of the pipeline. In order to ensure the safe, effective and stable operation of the pipeline in service, nondestructive testing must be carried out regularly. Traditional manual nondestructive testing (NDT) has been the main means of periodic inspection of industrial pipelines in the past. With the improvement of the level of industrial automation, automated NDT has become a research hotspot. Among the many nondestructive testing, ultrasonic testing has become the main technology of automatic nondestructive testing because of its own characteristics, and automatic ultrasonic testing has been more and more popular because of its high detection efficiency, good scanning repeatability and so on. In this paper, based on the engineering application research project of China Special equipment testing Institute, "the development of feedback automatic scanning device for pipeline", the automatic scanning device is designed by using the method of diffraction time difference (TOFD) ultrasonic detection as the technical means. The automatic TOFD detection of the circumferential welds of existing pipelines was carried out by means of the TOFD probe mounted on the sweeper. The main research work is as follows: (1) the research status of the automatic scanning system for pipe girth weld at home and abroad is analyzed, and the advantages and disadvantages of several kinds of automatic sweeper are compared, and the structure of the existing automatic sweeper is complex. This paper presents the design of a more flexible, convenient and compact automatic scanner. The scanning device adopts the structure of magnetic wheel adsorbed trolley. Compared with the existing automatic scanning device, CCD tracking function is added to realize automatic deviation correction. At the same time, wireless control is used. (2) complete the design of the mechanical structure and key components of the scanner. (3) the circuit schematic diagram is completed by the design of the main controller module, such as CCD acquisition module, motor driving module, wireless remote control module and power conversion module. Finally, the PCB board is made, the relevant components are welded, and the whole hardware circuit system is designed and fabricated. (4) the control flow of the sweeper is planned, and the black line extraction algorithm and pid control algorithm are used, respectively. The CCD tracking control and PWM motor control are accomplished by programming. The motor model is established to simulate the motor performance. The Simulink model of the control system is established in Matlab, and the whole control system is simulated. The system simulation response curve can meet the requirements of fast response time and stable operation. (5) the test is carried out in the laboratory environment and the industrial field respectively, and it is verified that the operation index of the automatic scanner can meet the requirements of industrial field detection.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG441.7

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