旋转磁场井间随钻测距导向系统中微弱频变信号的检测方法  

A weak and frequency-varying signal detection method for rotating magnet ranging system

作　　者：梁华庆[1] 耿敏[1] 时东海[1] 史超[1] 高德利[2] 

机构地区：[1]中国石油大学地球物理与信息工程学院,北京102249 [2]中国石油大学石油工程学院,北京102249

出　　处：《中国石油大学学报（自然科学版）》2013年第4期83-87,99,共6页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家科技重大专项(2011ZX05009-005);中国石油大学(北京)基金资助项目(KYJJ2012-05-33)

摘　　要：针对旋转磁场信号的微弱且频变的特点,提出并实现一种基于离散傅里叶变换(DFT)双谱峰的频率重构方法。在信号幅度谱主瓣内搜索两个谱峰的频率,以此重构信号频率的初值,运用牛顿迭代算法求解信号的真实频率,恢复信号幅度。通过计算机仿真和室外模拟对算法进行测试。结果表明:仿真结果优于基于DFT的单谱峰方法,模拟试验结果符合磁场信号随距离变化的规律,验证了所提方法的有效性和准确性;该方法能够准确锁定变化的磁场频率,滤除其他频率的杂波和噪声,精确提取出微弱的磁场幅度。According to the weak and frequency-varying characteristics of rotating magnetic signal, a filtering method was developed based on discrete Fourier transform （DFT） double-peak spectrum value. Firstly, the frequencies of two peaks in the main-lobe of sig-nal amplitude spectrum were searched. Secondly, the initial frequency value was reconstructed based on the two frequencies and the true frequency value was solved by Newton＇s method. Finally, the signal amplitude was recovered. The proposed method was tested by computer simulation and outdoor experiments. The simulation results show that the double-peak method is much better than the single-peak method based on DFT. The experimental results agree well with the variation law of magnetic field strength with distance. The proposed method is proved to be effective and accurate. The method can track the varing frequency aeeuratly and extract the weak am-plitude precisely.

关 键 词：信号检测 微弱频变信号 频率重构 离散傅里叶变换 旋转磁场 测距导向系统 

分 类 号：TE243[石油与天然气工程—油气井工程]