地下燃气管线是城市基础设施的重要组成部分，是城市的重要“生命线”。但由于一些老旧管道的腐蚀，以及各种人为或者自然的第三方破坏，导致各类燃气泄漏事故频发，严重威胁了城市系统的安全。因此研究地下燃气管道泄漏的早期监测和预警具有重大的研究价值和现实意义。鉴于现有人工巡检燃气泄露监测方式效率低、检测周期长、人力成本高等不足，本文基于物联网技术研发了地下燃气管道泄漏监测系统。研发基于可调谐二极管激光吸收光谱技术的气体探测器、GPRS数据传输模块、GPS接收模块和微控制单元MCU模块多功能模块高度集成的燃气泄漏监测硬件系统，实现了燃气泄露浓度数据的远程采集和传输。设计针对大范围燃气管道泄漏的解决方案，阐述了硬件系统的工作模式，提出了移动传感器终端为主、固定传感器终端为辅的移动-固定相结合的监测方法，并对移动传感器终端和固定传感器终端的工作模式做智能化设计。设计与开发了软件系统，实现了实时数据的接收和处理功能，完成基于测量数据的泄漏源位置溯源计算，并实现了现场数据和泄漏源数据的在线展示和远程访问功能。开展实地实验，测试固定传感器终端和移动传感器终端的测量效果，同时根据现场测量数据开展溯源算法的验证计算，根据与已知泄漏源位置的比较证明了溯源算法的可行性和准确性。本文研发了基于物联网技术的地下燃气管道泄漏监测系统，可实现大范围全天候的实时燃气泄漏监测和早期预警，能够为燃气公司和相关政府职能部门的应急决策和应急响应提供可靠的决策支持。

The underground gas pipeline is an significant part of urban infrastructure which is named the "lifeline" of the urban system. However, due to the natural corrosion, accidental damage or others reasons, a lot of accident for the gas pipeline leakage and had affected the city's safe seriously. Therefore, it is well worth to study a method of early monitoring and warning of underground gas pipeline leakage.In this paper, based on the features of low efficiency, long inspection cycle, high cost of the manual inspection, a monitoring system is deveploped for underground gas pipelines leakage based on the Internet of thing. A high-integrated and multifunctional gas leakage monitoring hardware system is developed, including the gas detector based on tunable diode laser absorption spectroscopy(TDLAS) technology, a GPRS transmission module, a GPS receiver module and a micro control unit(MCU) module. Besides, it proposes a solution for the underground gas pipelines leakage monitoring of large-scale area, adopts mobile sensor terminal supplemented fixed sensor terminal working mode, and disigns the working mode of the mobile sensor terminals and fixed sensor terminals with a intelligent method.A software system is designed and developed. it realizes the real-time data receiving and processing functions, complete the leak point location according to the inversion algorithm and collected data, and achieves the functions of data display and remote access for real-time data and leak point data.The field experiments are carried out with the hardware system to test the measurement result of mobile detector and stationary detector. Simultaneously, it verifies the accuracy of inversion algorithm with the field measurement data according to the comparison with the known leaka point location, and it proves the adopted inversion algorithm is effective and feasible.In this paper, a online monitoring system for gas leakage based on the Internet of thing is developed, and it can be implemented on large-scale area underground pipelines to realize remotely real-time monitoring and early warning. it is able to help the gas company and related staffs to take emergency action in time to dispose the leakage accident.