WU Zuo-peng, WANG Xiao-peng, WU Xu
（School of Electronic and Information Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China）
Abstract： In the measurement of liquid level in industrial site environment, noise interference can affect the measurement accuracy. In order to improve the measurement accuracy of liquid level in the viscous state, a nuclear radiation level measurement system based on the least mean square (LMS) filtering correction method is designed. The system uses STM32F103 as the control core and adopts HART bus HT1200M chip for remote signal transmission and reception. The adaptive LMS algorithm can be used for more accurate filtering, calculating iterative weight vector, updating weighted coefficient, effectively removing system measurement noise and improving the measurement accuracy. The results show that the nuclear radiation level gauge based on normalized LMS can correct the measurement system accuracy in adaptive rules, improve the measurement accuracy to meet the requirements of industrial field environment for liquid level measurement and enhance the industrial automation control degree.
Key words： least mean square (LMS); nuclear radiation method; self-adaptive algorithm; weighted coefficient updating; level gauge
CLD number： TP273 Document code： A
Article ID： 1674-8042（2019）02-0103-06 doi： 10.3969/j.issn.1674-8042.2019.02.001
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基于归一化LMS滤波校正的核辐射法液位计设计
吴作鹏， 王小鹏， 吴旭
（兰州交通大学 电子与信息工程学院， 甘肃 兰州730070）
摘要： 在工业现场环境对液位的测量中， 噪声的干扰会影响测量精度。 为提高粘稠状态下液位测量精度， 设计了一种基于归一化最小均方误差（LMS）滤波方法校正的核辐射法液位测量系统。 以STM32为控制核心， 利用基于HART总线HT1200M芯片进行数据传输与接收， 归一化LMS滤波算法能够进行更精确的滤波处理， 计算系统迭代权矢量， 进行权系数更新， 有效消除系统液位测量噪声， 提高液位测量精度。 测试数据表明， 归一化LMS滤波方法校正的核辐射法液位计在自适应规则下能够消除测量系统噪声干扰， 提高液位测量精度， 液位计能够满足工业现场环境对液位测量要求， 能够提高相关工业自动化程度。
关键词： 最小均方误差； 核辐射法； 自适应算法； 权系数更新； 液位计
引用格式：WU Zuo-peng, WANG Xiao-peng, WU Xu. Design of nuclear radiation level gauge based on normalized LMS filtering correction. Journal of Measurement Science and Instrumentation, 2019, 10（2）： 103-108. ［doi： 10.3969／j.issn.1674-8042.2019.02.001］
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