\r王 超，邹 萍，崔自强，何瀚辰，曹晴晴，王化祥\r
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AuthorsHTML:\r王 超，邹 萍，崔自强，何瀚辰，曹晴晴，王化祥\r
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AuthorsListE:\rWang Chao，Zou Ping，Cui Ziqiang，He Hanchen，Cao Qingqing，Wang Huaxiang\r
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AuthorsHTMLE:\rWang Chao，Zou Ping，Cui Ziqiang，He Hanchen，Cao Qingqing，Wang Huaxiang\r
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Unit:\r天津大学电气自动化与信息工程学院，天津 300072\r
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Unit_EngLish:\rSchool of Electrical and Information Engineering，Tianjin University，Tianjin 300072，China\r
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Abstract_Chinese:\r为实现对流化床中磁性催化剂颗粒分布的实时监测，对EMT 技术应用于磁导率分布测量的可行性展开研究．常规EMT 系统一般用于重建电导率分布，且采用线圈进行检测，存在检测灵敏度低、测量数据少的问题，为此采用灵敏度高、体积小的线性TMR 传感器替代测量线圈，设计了新的TMR-线圈传感器阵列，对阵列中TMR 传感器的敏感轴方向进行了优化，在此基础上选择多维公司TMR2905 作为测量器件．结合仿真软件COMSOL Multiphysics和MATLAB，利用模拟扰动法建立了TMR-线圈传感器阵列的灵敏度矩阵．使用Landweber 迭代算法求解逆问题，为保证重建图像质量并防止过迭代，设置相邻两次重建结果的剩余测量矢量的差值作为迭代停止条件，通过多次测试选定系统在低固含率和高固含率条件下的迭代阈值分别为0.001 和0.050．在仿真和实验平台中针对4 种不同的磁导率分布情况进行图形重建，结果表明仿真和实验的重建图像均可以正确反映磁导率在敏感场中的分布信息，验证了TMR-线圈传感器阵列用于测量流化床中磁性催化剂颗粒分布的可行性．为了进一步提高重建图像的质量，通过仿真研究了TMR 传感器数量对EMT 系统重建图像质量的影响：当TMR 传感器从8 个增加到16 个后，重建图像与实际分布图像的相关系数在4 种不同磁导率分布情况下较原来平均提高23.8%．\r
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Abstract_English:\rTo study the real-time monitoring of the magnetic catalyst particles distribution in fluidized beds，the feasibility of applying linear electromagnetic tomography(EMT)technology to the measurement of permeability distribution is studied in this paper. Conventional EMT systems focus on the reconstruction of the conductivity and use measurement coils as detectors，resulting in a low sensitivity of detection and low number of measurements. To solve these problems，tunneling magneto resistance(TMR)sensors are implemented to replace the measurement coils in our system because of their high sensitivity and small size. A novel TMR-coil sensor array has been designed，and the directions of the TMRs’ sensitivity axes have been optimized. On this basis，the TMR2905 of Multi Dimension Corporation is chosen as the measuring device. Using both simulation software COMSOL Multiphysics and MATLAB，the sensitivity matrix of this new array with respect to relative permeability is established according to a perturbation method of simulation. The Landweber iteration algorithm is used to solve the inverse problem in this paper. To ensure the quality of the reconstructed image and prevent over iteration，the difference between the remaining measurement vectors of the two adjacent reconstructed results is set as the stopping condition of the iteration. According to several tests，the iteration thresholds are determined to be 0.001 and 0.050 under low and high solid holdup，respectively. Next，image reconstruction is conducted using both simulation and experiment under four types of permeability distributions. Results show that reconstructed images of both simulation and experiment can correctly reflect the distribution of permeability in the interested field，thereby verifying the feasibility of TMR-coil sensor array’s application in the measurement of magnetic catalyst particles in the fluidized bed. To improve the quality of image reconstruction，the influence of the number of TMR sensors on the quality of the reconstructed image was studied by simulation：when the TMR sensor is increased from 8 to 16，the correlation coefficient between the reconstructed image and the actual distribution increases by an average of 23.8% under four different permeability distributions.\r
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Keyword_Chinese:电磁层析成像；磁性催化剂；隧道磁电阻；传感器阵列设计；图像重建\r

Keywords_English:electromagnetic tomography；magnetic catalyst；tunneling magneto resistance(TMR)；sensor array design；image reconstruction\r


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