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摘要:
数字锁相解调器是电磁无损检测中弱信号处理的重要方法,针对其性能优化,设计一种引入卡尔曼滤波器的数字锁相解调器,该解调器兼具了强抗噪能力及良好的动态跟踪响应特性。利用卡尔曼低通滤波器截止频率随迭代次数下降的特性,结合零点频率,设计了数字锁相解调器中的低通滤波环节,实现了非常窄的锁相带通,进而提高了抗击强噪声干扰能力。此外,利用卡尔曼滤波器的迭代预测-更新特点,实现了数字锁相解调器较小的响应时间,进而改善了数字锁相解调器的动态跟踪响应特性。仿真和检测实验证明所设计数字锁相解调器具有较高的抗噪能力和良好的动态跟踪响应特性,在电磁无损检测中能够精确、快速捕捉检测信号中包含的缺陷信息。
Abstract:Digital phase-locked demodulator is an important method for weak signal processing in electromagnetic non-destructive testing. For its performance optimization, a digital phase-locked demodulator with Kalman filter is designed, which has strong anti-noise ability and good dynamic tracking features. By using the characteristic that the cut-off frequency of Kalman low-pass filter decreases with the number of iterations and combining with the zero frequency, we design a low-pass filter in a digital phase-locked demodulator and then realize very narrow phase-locked bandpass, which improves the ability of strong noise resistance. In addition, using the predictive-update feature of the Kalman filter, the smaller response time of the digital phase-locked demodulator is realized, thereby improving the dynamic tracking characteristics of the digital phase-locked demodulator. Simulation and detection experiments show that the designed digital phase-locked demodulator has high noise immunity and good dynamic tracking response. It can accurately and quickly capture the defect information contained in the detection signal in electromagnetic non-destructive testing.
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表 1 不同噪声扰动大小以及r/q的值
Table 1. Different noise disturbance and value of r/q
编号 噪声幅值/V SNR/dB RC截止频率/kHz r/q DC 干扰频率为50Hz 干扰频率为100kHz 1 0 0 0 30 4 104 2 1 1 1 30 0.7 104 3 1 1 1 10 4 104 4 1 1 1 1 0.7 104 5 1 1 1 1 0.7 107 6 1 1 1 1 0.7 109 -
[1] 王化祥, 曹章.基于锁相放大器的低通滤波环节优化设计[J].仪器仪表学报, 2005, 26(7):684-689. doi: 10.3321/j.issn:0254-3087.2005.07.007WANG H X, CAO Z.Optimization of low pass filter design in lock-in amplifier[J].Chinese Journal of Scientific Instrument, 2005, 26(7):684-689(in Chinese). doi: 10.3321/j.issn:0254-3087.2005.07.007 [2] 尹武良, 王奔, 王化祥.电磁层析成像中基于半周期采样的数字解调方法[J].天津大学学报(自然科学与工程技术版), 2011, 44(12):1118-1123. http://d.old.wanfangdata.com.cn/Periodical/tianjdxxb201112014YIN W L, WANG B, WANG H X.Digital demodulation based on half-period sampling in electromagnetic tomography[J].Journal of Tianjin University (Science and Technology), 2011, 44(12):1118-1123(in Chinese). http://d.old.wanfangdata.com.cn/Periodical/tianjdxxb201112014 [3] 王野, 谭超, 董峰.多激励频率模式的磁感应层析成像系统[J].北京航空航天大学学报, 2017, 43(11):2331-2337. http://bhxb.buaa.edu.cn/CN/abstract/abstract14279.shtmlWANG Y, TAN C, DONG F.Magnetic induction tomography system with multi-excitation frequency mode[J].Journal of Beijing University of Aeronautics and Astronautics, 2017, 43(11):2331-2337(in Chinese). http://bhxb.buaa.edu.cn/CN/abstract/abstract14279.shtml [4] 周正干, 贺鹏飞, 赵翰学, 等.钛合金蜂窝结构蒙皮脱焊缺陷锁相红外热成像检测[J].北京航空航天大学学报, 2016, 42(9):1795-1802. http://bhxb.buaa.edu.cn/CN/abstract/abstract13726.shtmlZHOU Z G, HE P F, ZHAO H X, et al.Detection of skin desoldering defect in Ti-alloy honeycomb structure using lock-in infrared thermography test[J].Journal of Beijing University of Aeronautics and Astronautics, 2016, 42(9):1795-1802(in Chinese). http://bhxb.buaa.edu.cn/CN/abstract/abstract13726.shtml [5] LIU Z, ZHU L, KOFFMAN A, et al.Digital lock-in amplifier for precision audio frequency bridge[C]//2012 Conference on Precision Electromagnetic Measurements.Piscataway, NJ: IEEE Press, 2012: 586-587. [6] LIU Z, LI W, XUE F, et al.Electromagnetic tomography rail defect inspection[J].IEEE Transactions on Magnetics, 2015, 51(10):1-7. http://d.old.wanfangdata.com.cn/NSTLQK/NSTL_QKJJ0235383759/ [7] MASCIOTTI J M, LASKER J M, HIELSCHER A H.Digital lock-in detection for discriminating multiple modulation frequencies with high accuracy and computational efficiency[J].IEEE Transactions on Instrumentation & Measurement, 2008, 57(1):182-189. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=45c14579870d1ecf1c86d2e8a9de17de [8] 黄佳亮.微弱信号检测的噪声和处理方法[J].仪器仪表与分析监测, 1995(1):38-54. http://d.old.wanfangdata.com.cn/Thesis/D517248HUANG J L.The noise and processing method of weak signal detecting[J].Instrumentation Analysis Monitoring, 1995(1):38-54(in Chinese). http://d.old.wanfangdata.com.cn/Thesis/D517248 [9] 周浩敏, 赵巧转, 汤章阳.谐振式微小型压力传感器数字闭环系统[J].北京航空航天大学学报, 2006, 32(11):1312-1315. doi: 10.3969/j.issn.1001-5965.2006.11.012ZHOU H M, ZHAO Q Z, TANG Z Y.Closed loop systems of resonant small sensors and micro-sensors based on DSP technology[J].Journal of Beijing University of Aeronautics and Astronautics, 2006, 32(11):1312-1315(in Chinese). doi: 10.3969/j.issn.1001-5965.2006.11.012 [10] SUN S, XU L, CAO Z, et al.Digital recursive demodulator based on Kalman filter[J].IEEE Transactions on Instrumentation & Measurement, 2017, 66(12):3138-3147. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=daec77e68c0e4c797d1fafe4ed56711f [11] 李刚, 张丽君, 林凌.一种新型数字锁相放大器的设计及其优化算法[J].天津大学学报(自然科学与工程技术版), 2008, 41(4):429-432. http://d.old.wanfangdata.com.cn/Periodical/tianjdxxb200804009LI G, ZHANG L J, LIN L.Design of a new digital lock-in amplifier and its optimization algorithm[J].Journal of Tianjin University(Science and Technology), 2008, 41(4):429-432(in Chinese). http://d.old.wanfangdata.com.cn/Periodical/tianjdxxb200804009 [12] VAINIO O.Minimum-phase FIR filters for delay-constrained noise reduction[J].IEEE Transactions on Instrumentation & Measurement, 1999, 48(6):1100-1102. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=43a184ecc43a8ef73b24d97def912cde [13] CHENG Y.A linear algebraic approach to Kalman filtering[C]//International Conference on Measuring Technology and Mechatronics Automation.Piscataway, NJ: IEEE Press, 2010: 122-125. [14] COOPER W S.Use of optimal estimation theory, in particular the Kalman filter, in data analysis and signal processing[J].Review of Scientific Instruments, 1986, 57(11):2862-2869. doi: 10.1063/1.1139005 [15] 薛明喜, 杨扬, 张晨睿, 等.基于自适应Kalman滤波的SAW测温数据纠错方法[J].仪器仪表学报, 2016, 37(12):2766-2773. http://d.old.wanfangdata.com.cn/Periodical/yqyb201612015XUE M X, YANG Y, ZHANG C R, et al.Error correction method for SAW temperature measurement data based on adaptive Kalman filter[J].Chinese Journal of Scientific Instrument, 2016, 37(12):2766-2773(in Chinese). http://d.old.wanfangdata.com.cn/Periodical/yqyb201612015 [16] 刘国海, 李沁雪, 施维, 等.动态卡尔曼滤波在导航试验状态估计中的应用[J].仪器仪表学报, 2009, 30(2):396-400. doi: 10.3321/j.issn:0254-3087.2009.02.032LIU G H, LI Q X, SHI W, et al.Application of dynamic Kalman filtering in state estimation of navigation test[J].Chinese Journal of Scientific Instrument, 2009, 30(2):396-400(in Chinese). doi: 10.3321/j.issn:0254-3087.2009.02.032 [17] 张猛, 肖曦, 李永东.基于扩展卡尔曼滤波器的永磁同步电机转速和磁链观测器[J].中国电机工程学报, 2007, 27(36):36-40. doi: 10.3321/j.issn:0258-8013.2007.36.007ZHANG M, XIAO X, LI Y D.Speed and flux linkage observer for permanent magnet synchronous motor based on EKF[J].Proceedings of the CSEE, 2007, 27(36):36-40(in Chinese). doi: 10.3321/j.issn:0258-8013.2007.36.007 [18] COELHO R, ALVES D.Real-time lock-in amplifier implementation using a Kalman filter for quasi-periodic signal processing in fusion plasma diagnostics[J].IEEE Transactions on Plasma Science, 2009, 37(1):164-170. doi: 10.1109/TPS.2008.2006976 [19] COELHO R, ALVES D, HAWKES N, et al.Real-time data processing and magnetic field pitch angle estimation of the JET motional Stark effect diagnostic based on Kalman filtering[J].Review of Scientific Instruments, 2009, 80(6):164-168. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=28f6422b616b4421b2e06a385b344844 [20] ALVES D, COELHO R, KLEIN A, et al.A real-time synchronous detector for the TAE antenna diagnostic at JET[J].IEEE Transactions on Nuclear Science, 2010, 57(2):577-582. doi: 10.1109/TNS.2009.2033679 [21] 赵汝进, 马孜, 姚远程, 等.基于广义卡尔曼滤波的光学膜厚监控信号处理[J].激光技术, 2007, 31(4):412-415. doi: 10.3969/j.issn.1001-3806.2007.04.006ZHAO R J, MA Z, YAO Y C, et al.Monitor signal processing of optic thin film based on generalized Kalman filters[J].Laser Technology, 2007, 31(4):412-415(in Chinese). doi: 10.3969/j.issn.1001-3806.2007.04.006 [22] 董玉辉.卡尔曼滤波在原子磁力仪中的应用研究[D].哈尔滨: 哈尔滨工程大学, 2016.DONG Y H.Application research of Kalman filter in optical atomic magnetometer[D].Harbin: Harbin Engineering University, 2016(in Chinese). -