基于自适应滤波的暗电流消除设计
Dark current elimination design based on adaptive filtering
宋佳钫 1孙自闯1
作者信息
- 1. 天津工业大学机械工程学院,天津 300387
- 折叠
摘要
暗电流作为光电探测器的固有噪声,是影响双光束分光光度计检测性能的重要因素.为消除此影响,提出自适应滤波双光束分光光度计.首先,设计实时暗电流检测系统,能在每个检测周期内捕获样品信号、参考信号和暗电流信号.其次,针对时域差异引起的暗电流消除问题,引入自适应级联滤波算法(Recursive Least Squares and Normalized Least Mean Squares,RLS-NLMS),算法采用三级级联滤波模型,一级局部均值(Lo-cal Mean,LM)降低暗电流与检测信号之间的相关性,二级低阶RLS滤波器用于检测信号滤波,三级高阶NLMS滤波器用于处理RLS输出信号.实验结果显示,自适应滤波双光束分光光度计的透射比相对误差仅为1.46％,较传统方法降低了 66％,在暗电流消除方面表现出色,具有实际应用价值.
Abstract
Dark current,as an inherent noise in photodetectors,significantly affects the detection performance of dual-beam spectrophotometers.To mitigate this impact,an adaptive filtering dual-beam spectrophotometer is pro-posed.Firstly,a real-time dark current detection system is designed to capture the sample signal,reference signal,and dark current signal within each detection cycle.Secondly,an adaptive cascaded filtering algorithm called Recur-sive Least Squares and Normalized Least Mean Squares(RLS-NLMS)is introduced to address the issue of dark cur-rent elimination caused by temporal differences.The algorithm employs a three-level cascaded filtering model.The first level,local mean(LM),reduces the correlation between dark current and the detection signal.The second level utilizes a low-order RLS filter for signal filtering,while the third level employs a high-order NLMS filter to process the output signal from RLS.Experimental results demonstrate that the adaptive filtering dual-beam spectrophotometer a-chieves a relative error of only 1.46％in transmittance ratio measurement,reducing it by 66％compared to traditional methods.It exhibits excellent performance in dark current cancellation and holds significant practical value.
关键词
暗电流/双光束分光光度计/光电探测器/分光系统/级联滤波Key words
dark current/double beam spectrophotometer/photodetector/spectroscopic system/cascade filtering引用本文复制引用
出版年
2024
NETL
NSTL
万方数据