摘要
研究目的:针对传统Duffing振子在ZPW-2000移频信号检测时存在小频率参数限制、初相角导致的检测盲区及对检测结果只是定性判断的问题,本文在检测方法上做出改进,得到一种改进型Duffing振子检测系统。研究结论:(1)对传统Duffing方程进行广义时间尺度变换,得到可检测任意频率信号的检测模型;(2)对待测信号存在初相角而可能使检测出现盲区的情况,使内策动力产生一定的相移量来实现检测盲区的消除;(3)为了得到准确的检测结果,在对相图及时域图定性判断的基础上,提出一种基于检测统计量的定量方法对检测结果实现精确判定,通过仿真验证得出此方法的检测精度高于定性判断;(4)将改进后的Duffing振子检测系统首次应用于ZPW-2000移频信号的检测,给出了检测步骤,仿真结果表明改进后的Duffing振子检测系统可在低信噪比下实现ZPW-2000移频信号的检测;(5)本研究成果可在强噪声背景条件下进行ZPW-2000移频信号的准确检测。
Research conclusions： （ 1 ） transformation to traditional The detection model of any frequency signal is obtained by using the general time scale Duffing equation. （2） Bacause the initial phase angle may make the detecting blind angle in the measured signal, the detection blind angle is eliminated by making the original driven signal phase shift a degree. （3） In order to obtain the accurate detection results, on the basis of the qualitative judgment of the phase diagram and time domain diagram, a quantitative method based on the detection statistic is proposed to realize the accurate determination to the detection results. The simulation obtains that the detection accuracy of this method is higher than qualitative judgment. （4） The improved Duffing oscillator detection system is first applied to the detection of ZPW -2000 shift frequency signal. The steps of detection are given. The simulation results show that the detection system of improved Duffing oscillator can realize the detection of ZPW -2000 shift signal in low SNR. （5） The research outcome will realize the accurate detection of ZPW - 2000 shift signal in background of strong noise.
出处
《铁道工程学报》
EI
北大核心
2016年第9期104-112,共9页
Journal of Railway Engineering Society
基金
国家自然科学基金地区项目(61164010)
