【作者】 张双楠；

【导师】 杨理践；

【作者基本信息】 沈阳工业大学 ， 检测技术与自动化装置， 2009， 硕士

【摘要】 漏磁检测是长距离油气输送管道进行在线检测的主要方法。应用管道漏磁在线检测装置可以及时检测出管道的缺陷,预防管道泄漏事故的发生。由于存储漏磁检测数据所用电子硬盘存储数据量少,因此需要有实时的数据采集、压缩、存储系统。本文开发了基于ARM(Advanced RISC Machines,高级精简指令集计算机)的嵌入式为核心的处理器平台,用于实现管道漏磁检测数据的实时采集、压缩与存储。论文提出了一种新型的以ARM处理器为核心的系统设计方案。针对漏磁检测无损压缩的目的、应用及漏磁检测原理和漏磁检测数据特征的研究,利用了LZW算法和Hash表的理论,提出了对漏磁检测数据进行实时无损压缩的算法。实时无损压缩算法采用了LZW算法对漏磁检测数据进行无损压缩,Hash表算法管理LZW算法的字符串表的方法。最后基于ARM硬件平台嵌入Linux操作系统,开发了基于Linux的采集设备驱动程序,并应用嵌入式技术实现了系统应用软件完成漏磁数据的采集、压缩与存储。利用嵌入式ARM处理器的优势,进行软硬协同设计;利用ARM处理器的数据采集模块,提高了系统的运算能力和可靠性,Linux操作系统的使用提高了前端数据的采集精度,简化了与外围设备的通信,进一步缩短了开发周期,降低了开发成本,同时漏磁检测数据实时压缩算法满足2倍以上的压缩比,实时压缩数据。针对系统设计实现的各功能模块,分别给出了验证方法及结果。实验表明:各功能模块运行稳定、性能良好,可以应用于管道漏磁检测数据压缩系统中。更多还原

【Abstract】 Magnetic Flux Leakage (MFL) inspection is the main method of on-line inspecting long distance oil-gas transportation pipeline. Pipeline MFL inspection device is applied to detect defects of pipeline in time in order to prevent pipeline leakage accident. Because of MFL data storage used in electronic data storage hard disk volume, it has required real-time data acquisition, compression, storage systems In this paper, an embedded system based on ARM (Advanced RISC Machines) is developed with Linux embedded technology, the system is used to realize the real-time acquisition, compression and storage of pipeline MFL inspection data.First, the defects of current MFL inspection system aiming at the defects, a new system design scheme which applys FPGA is presented, and the hardware system based on a single ARM is designed according to system requirements. The aim and application of diagnostically lossless compression and the data compression method for magnetic flux leakage (MFL) inspection of pipelines is introduced. By analyzing the principle of MFL and the character of the MFL inspection data, uses the LZW algorithm to magnetic flux leakage data in real-time lossless compression. In order to accelerating the speed of data compression, the algorithm also uses Hash method to manage the string table of LZW algorithm. Based on Linux, the drive program of acquisition device is developed and the system software implementing data acquisition, compression and storage is designed with multithreads technology.Utilizing ARM technology, hardware & software co-design can be employed freely; In the same time, reliability and operation power of the system are improved greatly via applying ARM to control data acquisition module; Besides, the utilization of Linux operating system enhances the acquisition precision of frontal data, simplify the communication between ARM and peripheral equipment, shortens further system development time and reduced design cost. The algorithm can realized more than 2 times the data compression. The real-time of the program is better, and the program realized 2 times more data compression. And the realization of magnetic flux leakage data acquisition, compression, storage. Aiming at each functional module designed in the system, testing methods and corresponding results are presented respectively in the paper. Experiments indicate that each functional module can run stably with good performance, and they can be used in the pipeline MFL inspection device with no problems.更多还原