scholarly journals Flipped parameter technique applied on source localization in energy constraint sensor arrays

2009 ◽  
Vol 7 (1) ◽  
pp. 7-22
Author(s):  
Vlastimir Pavlovic ◽  
Zoran Velickovic

In this paper novel flipped parameter technique (FPT) for time delay estimation (TDE) in source localization problem is described. We propose passive source localization technique based on the development of an energy efficient algorithm that can reduce intersensor and interarray communication. We propose a flipped parameter (FP) which can be defined for any sensor in distributed sensor subarrays during the observation period. Unlike classical TDE methods that evaluate cross-correlation function, FPT requires evaluation based upon single sensor signal. The computed cross correlation between a signal and its analytic 'flipped' pair (flipped correlation) is a smooth function which peak (time delay) can be accurately detected. Flipped parameters are sufficient to determine all differential delays of the signals related to the same source. The flipped parameter technique can be used successfully in two-step methods of passive source localization with significantly less energy in comparison to the classic cross correlation. The use of FPT method is especially significant for the energy constrain distributed sensor subarrays. Using synthetic seismic signals, we illustrate the error of the source localization for classical and proposed method in the presence of noise. We demonstrate the performance improvement in noise environment of the proposed technique in comparison to the classic methods that use real signals. The proposed technique gives accurate results for both coherent and non-coherent signals.

2013 ◽  
Vol 397-400 ◽  
pp. 2209-2214
Author(s):  
Chuan Yi Zhang ◽  
Chang Wei Mi ◽  
Pei Yang Yao

In the estimation of time delay, there always would not appear obvious peak with the basic cross-correlation (CC). In order to solve the problem of the basic cross-correlation method, this essay represents an improved time delay estimation method based on the generalized cross-correlation (GCC) and combines with the microphone array structure to achieve sound source localization. Finally, the simulation results show that this method could measure the sound source’s location accurately with noise and reverberation, and the distance positioning error is less than 10cm, the direction angle error is below 3°.


Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 351 ◽  
Author(s):  
Jakob Pfeiffer ◽  
Xuyi Wu ◽  
Ahmed Ayadi

Deviations between High Voltage (HV) current measurements and the corresponding real values provoke serious problems in the power trains of Electric Vehicle (EVs). Examples for these problems have inaccurate performance coordinations and unnecessary power limitations during driving or charging. The main reason for the deviations are time delays. By correcting these delays with accurate Time Delay Estimation (TDE), our data shows that we can reduce the measurement deviations from 25% of the maximum current to below 5%. In this paper, we present three different approaches for TDE. We evaluate all approaches with real data from power trains of EVs. To enable an execution on automotive Electronic Control Unit (ECUs), the focus of our evaluation lies not only on the accuracy of the TDE, but also on the computational efficiency. The proposed Linear Regression (LR) approach suffers even from small noise and offsets in the measurement data and is unsuited for our purpose. A better alternative is the Variance Minimization (VM) approach. It is not only more noise-resistant but also very efficient after the first execution. Another interesting approach are Adaptive Filter (AFs), introduced by Emadzadeh et al. Unfortunately, AFs do not reach the accuracy and efficiency of VM in our experiments. Thus, we recommend VM for TDE of HV current signals in the power train of EVs and present an additional optimization to enable its execution on ECUs.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Robert Hanus ◽  
Marcin Zych ◽  
Leszek Petryka ◽  
Dariusz Świsulski

Time delay estimation is an important research question having many applications in a range of technologies. Measurement of a two-phase flow in a pipeline or an open channel using radioisotopes is an example of such application. For instance, the determination of velocity of dispersed phase in that case is based on estimation of the time delay between two stochastic signals provided by scintillation probes. The proper analysis of such signals, usually in presence of noise, requires the use of advanced statistical signal processing. In this paper, the simulation studies of time delay estimation were carried out with the use of the following differential methods: average magnitude difference function, and average square difference function and proposed combined methods comprising the above-mentioned differential and cross-correlation functions are presented. Attached simulations have been carried out for models of stochastic signals corresponding to the signals obtained in gamma-ray absorption measurements of gas-liquid flow in a horizontal pipeline. The standard uncertainties of time delay estimations have been determined for each of the methods. Improved metrological properties have been stated in the combined methods in comparison with the classical cross-correlation procedure.


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