【作者】 程磊；

【导师】 童杏林；

【作者基本信息】 武汉理工大学 ， 物理学， 2023， 硕士

【摘要】 工业生产中对流量指标的监测需求日益增加,且因工况复杂,环境恶劣,对气体流量监测传感器有了更高的要求,期望能得到一种体积小、精度高、抗干扰能力强的新型流量传感器。针对现有传统流量传感器在工业实际生产中面临的各种限制,本文提出了一种高精度微型化光纤差压式流量传感器及系统,以光纤布喇格光栅(Fiber Bragg Grating,FBG)为敏感单元,具有本征防爆、抗电磁干扰、尺寸小、重量轻等优势,且在不改动原设备结构的前提下可以嵌入到目标内部进行检测,满足工业生产过程的恶劣应用条件。本文的主要研究工作如下:(1)分析和比较了国内外流量测量技术特点,结合光纤光栅传感器优势和敏感元件的承压机理,提出了高精度微型化光纤差压式流量传感器及系统。(2)基于FBG的温度、应变传感机制和弹性力学原理,设计了一种机内嵌喷嘴的FBG差压式流量传感器。详细分析了测量原理,并对传感器主体结构及封装工艺进行设计。通过COMSOL Multiphysics仿真软件对传感器的流量特性进行仿真,验证了传感器的结构合理性及抗干扰性能。最后根据仿真结果及封装设计,实际制作出了FBG差压式流量传感器,且能达到需要的体积小、质量轻的设计要求,便于工业监测安装。(3)研究了FBG流量传感系统的信号处理技术,提出了一种基于希尔伯特变换的自适应峰值区域分割算法,通过设置合适的阈值区间实现了对分布式FBG传感器反射光谱的波峰区域划分以及快速定位子光谱的功能;将传统的高斯算法进行改进优化,以便更好的对分割后的稀疏子光谱进行定位,系统测试结果表明该算法精确性和可靠性良好,在此研究基础上开发了FBG流量传感系统的数据流实时显示的上位机软件。(4)对所设计的传感器进行实验平台搭建及性能指标测试,包括静态标定实验和动态流量传感实验。对传感器的静态标定过程中显示传感器对温度和压力的响应线性度较好。最后对传感器的流量动态测试实验中各项性能指标进行分析,包括非线性度、迟滞、重复性、精度,其整体性能表现较好,能满足实际测量需求。更多还原

【Abstract】 The demand for monitoring flow indicators in industrial production is increasing,and due to the complex working conditions and harsh environment,there are higher requirements for gas flow monitoring sensors,and a new type of flow sensor with small size,high accuracy and strong anti-interference capability is expected.For the existing traditional flow sensor in the industrial production of various limitations,this paper proposes a high-precision miniaturized fiber differential pressure flow sensor and system,fiber Bragg Grating(FBG)as a sensitive unit,with intrinsic explosion-proof,anti-electromagnetic interference,small size,light weight and other advantages,and without changing the original equipment structure under the premise of It can be embedded inside the target for detection without changing the structure of the original equipment,meeting the harsh application conditions of industrial production processes.The main research work of this paper is as follows.(1)analyzed and compared the characteristics of domestic and foreign flow measurement technology,combined with the advantages of optical fiber grating sensor and the pressure-bearing mechanism of sensitive elements,and proposed a highprecision miniaturized optical fiber differential pressure flow sensor and system.(2)Based on the temperature and strain sensing mechanism of FBG and the principle of elastodynamics,an FBG differential pressure flow sensor with embedded nozzle is designed.The measurement principle is analyzed in detail,and the sensor body structure and packaging process are designed.The flow characteristics of the sensor are simulated by COMSOL Multiphysics simulation software to verify the structural rationality and anti-interference performance of the sensor.Finally,according to the simulation results and packaging design,the FBG differential pressure flow sensor is actually fabricated,and it can meet the required design requirements of small size and light weight,which is easy to install for industrial monitoring.(3)The signal processing technology of FBG flow sensing system is studied,and an adaptive peak region segmentation algorithm based on Hilbert transform is proposed to achieve the function of wave peak region segmentation and fast subspectrum localization of the reflected spectrum of distributed FBG sensors by setting a suitable threshold interval;the traditional Gaussian algorithm is improved and optimized for better localization of the segmented sparse subspectrum.The system test results show that the algorithm has good accuracy and reliability.Based on this study,the upper computer software for real-time data stream display of FBG flow sensing system is developed.(4)The designed sensor was tested on the experimental platform and performance indexes,including static calibration experiments and dynamic flow sensing experiments.The static calibration of the sensor shows good linearity of the sensor response to temperature and pressure.Finally,the performance indexes of the sensor in the dynamic flow test experiment are analyzed,including nonlinearity,hysteresis,repeatability,and accuracy,and its overall performance is good and can meet the actual measurement requirements.更多还原