Recently most researches in the field of delay estimation mcthods are concentrated on adaptive deconvolution. But It's well known that minimum delay resolution using deconvolution methods is the sampling interval ...Recently most researches in the field of delay estimation mcthods are concentrated on adaptive deconvolution. But It's well known that minimum delay resolution using deconvolution methods is the sampling interval of the original data. It is impossible to obtain cnough delay resolution in the case of short data records. In this paper, the limitation of the commonly used delay estimation methods are pointed out firstly. Then, two delay estimation methods with high resolution are presented, which are named delay- frequency estimation and eigenstructure methods. It's indicated that these two methods can resolve delays spaced closer than sampling interval. The principle and characteristics of them are described in detail, and the corresponding simulation results are given. At the last, a comparison table is listed to show the performance of main methods in delay estimation.展开更多
A novel rotational invariance technique for blind estimates of direction of arrival (I)OA) and Doppler frequency with unknown array manifold due to array sensor uncertainties is proposed, taking Doppler frequency diff...A novel rotational invariance technique for blind estimates of direction of arrival (I)OA) and Doppler frequency with unknown array manifold due to array sensor uncertainties is proposed, taking Doppler frequency difference between a successive pulses as rotational parameter. The effectiveness of the new method is confirmed by computer simulation. Compared with the existing 2-D DOA-frequeucy estimate techniques, the computation load of the proposed method can be saved greatly.展开更多
将高频率分辨力谱估计技术与优化算法相结合而提出一种新的异步电动机转子故障检测方法。针对两种典型的高频率分辨力谱估计技术——多重信号分类(multiple signalclassification,MUSIC)与旋转不变信号参数估计技术(estimation of signa...将高频率分辨力谱估计技术与优化算法相结合而提出一种新的异步电动机转子故障检测方法。针对两种典型的高频率分辨力谱估计技术——多重信号分类(multiple signalclassification,MUSIC)与旋转不变信号参数估计技术(estimation of signal parameters via rotational invariancetechnique,ESPRIT),应用模拟转子故障的定子电流信号测试其频率分辨力、精度等性能,结果表明:即使对于短时信号,二者仍具高频率分辨力,可以准确地分辨定子电流信号中转子故障特征分量、主频分量之频率;但对其幅值、初相角,仅能提供"粗糙"估计。为此,尝试以优化算法——模拟退火算法(simulated annealing algorithm,SAA)与模式搜索算法(pattern search algorithm,PSA)确定各分量的幅值与初相角。同时,分别对MUSIC与ESPRIT、SAA与PSA做了性能对比,遴选优者并应用于转子故障检测。最后,针对转子断条故障进行实验,结果表明:基于高频率分辨力谱估计技术与优化算法的异步电动机转子故障检测方法有效、可行,即使在负载波动、噪声等干扰严重情况下仍然适用。展开更多
叠前地震反演在储层预测与流体识别中起到了非常重要的作用,但常规振幅随角度变化(Amplitude Variation with Angle,AVA)三参数反演结果由于分辨率的限制已满足不了隐蔽油气藏勘探的高精度要求。为此,提出了一种综合利用隐含在叠前地震...叠前地震反演在储层预测与流体识别中起到了非常重要的作用,但常规振幅随角度变化(Amplitude Variation with Angle,AVA)三参数反演结果由于分辨率的限制已满足不了隐蔽油气藏勘探的高精度要求。为此,提出了一种综合利用隐含在叠前地震道集中的AVA信息与振幅随频率变化(Amplitude Variation with Frequency,AVF)信息的AVA多频信息同时反演的方法。首先对各入射角地震道集进行谱分解,得到振幅随角度和频率变化(Amplitude Variation with Angle and Frequency,AVAF)三维数据体,然后利用该数据体进行AVA多频信息同时反演,得到高分辨率的岩性参数反演结果。模型和实际资料应用结果表明,叠前AVA多频信息同时反演结果比常规AVA反演具有更高的分辨率,能更精细地刻画砂泥岩薄互层等隐蔽油气藏。展开更多
文摘Recently most researches in the field of delay estimation mcthods are concentrated on adaptive deconvolution. But It's well known that minimum delay resolution using deconvolution methods is the sampling interval of the original data. It is impossible to obtain cnough delay resolution in the case of short data records. In this paper, the limitation of the commonly used delay estimation methods are pointed out firstly. Then, two delay estimation methods with high resolution are presented, which are named delay- frequency estimation and eigenstructure methods. It's indicated that these two methods can resolve delays spaced closer than sampling interval. The principle and characteristics of them are described in detail, and the corresponding simulation results are given. At the last, a comparison table is listed to show the performance of main methods in delay estimation.
基金Supported by the National Natural Science Foundation of China
文摘A novel rotational invariance technique for blind estimates of direction of arrival (I)OA) and Doppler frequency with unknown array manifold due to array sensor uncertainties is proposed, taking Doppler frequency difference between a successive pulses as rotational parameter. The effectiveness of the new method is confirmed by computer simulation. Compared with the existing 2-D DOA-frequeucy estimate techniques, the computation load of the proposed method can be saved greatly.
文摘将高频率分辨力谱估计技术与优化算法相结合而提出一种新的异步电动机转子故障检测方法。针对两种典型的高频率分辨力谱估计技术——多重信号分类(multiple signalclassification,MUSIC)与旋转不变信号参数估计技术(estimation of signal parameters via rotational invariancetechnique,ESPRIT),应用模拟转子故障的定子电流信号测试其频率分辨力、精度等性能,结果表明:即使对于短时信号,二者仍具高频率分辨力,可以准确地分辨定子电流信号中转子故障特征分量、主频分量之频率;但对其幅值、初相角,仅能提供"粗糙"估计。为此,尝试以优化算法——模拟退火算法(simulated annealing algorithm,SAA)与模式搜索算法(pattern search algorithm,PSA)确定各分量的幅值与初相角。同时,分别对MUSIC与ESPRIT、SAA与PSA做了性能对比,遴选优者并应用于转子故障检测。最后,针对转子断条故障进行实验,结果表明:基于高频率分辨力谱估计技术与优化算法的异步电动机转子故障检测方法有效、可行,即使在负载波动、噪声等干扰严重情况下仍然适用。
文摘叠前地震反演在储层预测与流体识别中起到了非常重要的作用,但常规振幅随角度变化(Amplitude Variation with Angle,AVA)三参数反演结果由于分辨率的限制已满足不了隐蔽油气藏勘探的高精度要求。为此,提出了一种综合利用隐含在叠前地震道集中的AVA信息与振幅随频率变化(Amplitude Variation with Frequency,AVF)信息的AVA多频信息同时反演的方法。首先对各入射角地震道集进行谱分解,得到振幅随角度和频率变化(Amplitude Variation with Angle and Frequency,AVAF)三维数据体,然后利用该数据体进行AVA多频信息同时反演,得到高分辨率的岩性参数反演结果。模型和实际资料应用结果表明,叠前AVA多频信息同时反演结果比常规AVA反演具有更高的分辨率,能更精细地刻画砂泥岩薄互层等隐蔽油气藏。
