Time Delay Estimator for Boiler Tube Leakage Localization

2011 ◽  
Author(s):  
Liansuo An ◽  
Peng Wang ◽  
Guoqing Shen ◽  
Jie Shi
Keyword(s):  
Time Delay ◽  
Background Noise ◽  
Cross Correlation ◽  
Signal To Noise Ratio ◽  
Estimation Algorithm ◽  
Time Delay Estimation ◽  
Boiler Tube ◽  
Boiler Furnace ◽  
Direct Energy ◽  
Leakage Location

The inference of strong background noise and reflected by the wall and tube rows surface makes it impossible that justify accurately leakage position employing the characteristic received by multi-channel sensors. It is the ‘bottleneck’ for promoting the accuracy of boiler tube leakage location. The 600MW supercritical boiler model was established, the leakage source propagation process of reflection and attenuation in boiler furnace was simulated by EASE. The approximate signal to noise ratio (SNR) was obtained and the reverberation time was calculated with the squared impulse response integration method on the foundation of simulation. The time delay estimation algorithm PTN, SWITCH derived from PHAT and ML, respectively, are proposed and experiments results revealed the superiority over the classical generalized cross correlation (GCC) method in reverberant and noisy boiler background. Although SWITCH is outperformed by PTN slightly, but the prior knowledge of reverberant energy to direct energy ratio may be hard to obtain in practice and frequencies onset detection is required in PTN method, so the implementation of SWITCH is much easier.

The Algorithm of Acoustic Location for Boiler Tube Leakage

2010 ◽  
Vol 97-101 ◽  
pp. 3024-3027
Author(s):  
Peng Tong ◽  
Lian Suo An ◽  
Gen Shan Jiang ◽  
Yu Qing Wang
Keyword(s):  
Time Delay ◽  
Cross Correlation ◽  
Accurate Result ◽  
Correlation Method ◽  
Estimation Algorithm ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
Value Of Time ◽  
Noise Power ◽  
Boiler Tube

The time delay estimation algorithm based on generalized cross correlation, can suppress the noise power effectively. More accurate result can be gotten by this method of time delay estimation. It is proved by simulation and experimentation that the estimated value of time delay given by generalized cross correlation method is more accurate than which is given by basic correlation method when the signal and noise ratio is stationary, thus the location result based on the time delay is more accurate.

A Fast and Efficient Time-Delay Estimation Algorithm for Sound Localization

2011 ◽  
Vol 474-476 ◽  
pp. 1201-1204 ◽  
Author(s):  
Guan Qun Liu ◽  
Ru Bo Zhang ◽  
Dong Xu
Keyword(s):  
Time Delay ◽  
Sound Localization ◽  
Cross Correlation ◽  
Estimation Algorithm ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
Important Research ◽  
Memory Space ◽  
Important Research Topic ◽  
Original Time

Time-delay estimation is an important research topic of sound localization. According to the specificity of time-delay in sound localization, a fast and efficient time-delay estimation algorithm is proposed based on the principle of fast linear cross correlation. Relative to the original time-delay estimation algorithm based on fast linear cross correlation, the proposed algorithm has enormous advantages in the time complexity and space complexity. The computing speed is twice faster than the original time-delay estimation algorithm, while the size of the memory space used is half of the original time-delay estimation algorithm.

scholarly journals Time Delay Estimation Method Used Median Filter in Low Signal to Noise Ratio Pulse Environment

2021 ◽  
Vol 252 ◽  
pp. 02039
Author(s):  
Hang Liu ◽  
Wenhong Liu
Keyword(s):  
Signal Processing ◽  
Time Delay ◽  
Signal To Noise Ratio ◽  
Median Filter ◽  
Estimation Algorithm ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
P Value ◽  
Signal To Noise ◽  
Second Order Statistics

In practice, the collected signal often contains impulsive noise. The classical time delay estimation algorithm based on the second-order statistics of Gaussian distribution will degrade or even be unreliable, so that it cannot be used. Although the fractional low-order signal processing method can be better adapted to signal processing in the impulse noise environment, the determination of the order p value of the fractional low-order moment depends on the prior knowledge or estimation of the characteristic index α value of the pulse, and when the pulse is stronger or the signal-to-noise ratio is low, the performance cannot meet the requirements well. The paper adopted the method of median filter preprocessing. First, the abnormal points (pulse points) are removed in the noise and return the noise to the Gaussian model distribution; next, use the time delay estimation algorithm under the second-order statistics to avoid the estimate of p-value. Computer simulation experiments show that the method proposed in this paper has better estimation performance in low snr pulse environment.

scholarly journals Direction of Arrival Estimation Using Two Hydrophones: Frequency Diversity Technique for Passive Sonar

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2001 ◽  
Author(s):  
Peng Li ◽  
Xinhua Zhang ◽  
Wenlong Zhang
Keyword(s):  
Cross Correlation ◽  
Signal To Noise Ratio ◽  
Estimation Algorithm ◽  
Time Delay Estimation ◽  
High Signal ◽  
Frequency Diversity ◽  
Spectral Density Matrix ◽  
Processing Gain ◽  
The Cross ◽  
Diversity Technique

The traditional passive azimuth estimation algorithm using two hydrophones, such as cross-correlation time-delay estimation and cross-spectral phase estimation, requires a high signal-to-noise ratio (SNR) to ensure the clarity of the estimated target trajectory. This paper proposes an algorithm to apply the frequency diversity technique to passive azimuth estimation. The algorithm also uses two hydrophones but can obtain clear trajectories at a lower SNR. Firstly, the initial phase of the signal at different frequencies is removed by calculating the cross-spectral density matrix. Then, phase information between frequencies is used for beamforming. In this way, the frequency dimension information is used to improve the signal processing gain. This paper theoretically analyzes the resolution and processing gain of the algorithm. The simulation results show that the proposed algorithm can estimate the target azimuth robustly under the conditions of a single target (SNR = −16 dB) and multiple targets (SNR = −10 dB), while the cross-correlation algorithm cannot. Finally, the algorithm is tested by the swell96 data and the South Sea experimental data. When dealing with rich frequency signals, the performance of the algorithm using two hydrophones is even better than that of the conventional broadband beamforming of the 64-element array. This further validates the effectiveness and advantages of the algorithm.

scholarly journals Methods for mutual time delay estimation of wideband signals based on nonlinear digital filtering

2019 ◽  
Vol 30 ◽  
pp. 03008
Author(s):  
Roman Ershov ◽  
Oleg Morozov
Keyword(s):  
Time Delay ◽  
Communication Systems ◽  
Satellite Communication ◽  
Signal To Noise Ratio ◽  
Digital Filtering ◽  
Time Delay Estimation ◽  
Delay Estimation ◽  
Wideband Signals ◽  
Correlation Processing

Methods for mutual time delay estimation of wideband signals propagating in satellite communication systems are proposed. The signals are propagated in different channels and received with low signal-to-noise ratio. A characteristic feature of satellite channel is the presence of the Doppler Effect, which leads to a shift and scaling the signal spectrums. The proposed approaches are based on the separation of narrow-band channels from the studied signals, using non-linear digital filtering algorithms in each channel, and subsequent optimal (correlation) processing. The accuracy of the proposed methods and the reliability of the determination of time delay are investigated.

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