Improvement of synchronization accuracy in IEEE 1588 using a queuing estimation method

2009 ◽  
Author(s):  
Takahide Murakami ◽  
Yukio Horiuchi
Keyword(s):  
Estimation Method ◽  
Ieee 1588 ◽  
Synchronization Accuracy

scholarly journals Influence of Sampling Delay on the Estimation of Lithium-Ion Battery Parameters and an Optimized Estimation Method

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1878
Author(s):  
Bing Jiang ◽  
Zeqi Chen ◽  
Feifan Chen
Keyword(s):  
Estimation Method ◽  
Equivalent Circuit Model ◽  
Lithium Ion ◽  
Test System ◽  
Recursive Least Squares ◽  
Battery Management System ◽  
Battery Management ◽  
First Order ◽  
The Mathematical Model ◽  
Synchronization Accuracy

The equivalent-circuit model (ECM) is widely used in online estimating the parameters and states of lithium-ion batteries. However, the sampling delay between the voltage and current of a battery is generally overlooked, which is unavoidable in a modular battery management system (BMS) and would lead to wrong results in the estimation of battery parameters and states. In this paper, with the first-order resistor–capacitor (RC) model as our battery model, we analyze the influence mechanism of sampling delay and then propose an optimized method for online estimating battery parameters. The mathematical model derived from the first-order RC model and the approximation method of first-order derivative are optimized. The recursive least squares (RLS) algorithm is used for identifying the parameters of the model. In order to verify the proposed method, a modular battery test system with high sampling frequency and high synchronization accuracy is developed. The experiment results indicate that the sampling delay would cause the estimation process to fluctuate, and the optimized method effectively improves the tolerance range of sampling delay.

scholarly journals Maximum Likelihood Estimation of Clock Skew in IEEE 1588 with Fractional Gaussian Noise

2015 ◽  
Vol 2015 ◽  
pp. 1-24 ◽  
Author(s):  
Chagai Levy ◽  
Monika Pinchas
Keyword(s):  
Maximum Likelihood ◽  
Gaussian Noise ◽  
Likelihood Estimation ◽  
Packet Delay ◽  
Fractional Gaussian Noise ◽  
Clock Skew ◽  
Ieee 1588 ◽  
Accuracy And Precision ◽  
Ethernet Network ◽  
Synchronization Accuracy

To support system-wide synchronization accuracy and precision in the sub-microsecond range without using GPS technique, the precise time protocol (PTP) standard IEEE-1588 v2 is chosen. Recently, a new clock skew estimation technique was proposed for the slave based on a dual slave clock method that assumes that the packet delay variation (PDV) in the Ethernet network is a constant delay. However, papers dealing with the Ethernet network have shown that this PDV is a long range dependency (LRD) process which may be modeled as a fractional Gaussian noise (fGn) with Hurst exponent (H) in the range of0.5<H<1. In this paper, we propose a new clock skew estimator based on the maximum likelihood (ML) technique and derive an approximated expression for the Cramer-Rao lower bound (CRLB) both valid for the case where the PDV is modeled as fGn (0.5<H<1). Simulation results indicate that our new clock skew method outperforms the dual slave clock approach and that the simulated mean square error (MSE) obtained by our new proposed clock skew estimator approaches asymptotically the developed CRLB.

scholarly journals Time Synchronization Algorithm for Wireless Sensor Networks Based on Frequency Offset Estimation

2018 ◽  
Vol 14 (06) ◽  
pp. 71
Author(s):  
Shaojun Yu ◽  
Li Lin ◽  
Yujian Wang ◽  
Xingyuan Chen
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Time Synchronization ◽  
Estimation Method ◽  
Frequency Offset ◽  
Wireless Sensor ◽  
Frequency Offset Estimation ◽  
Dynamic Adjustment ◽  
Synchronization Algorithm ◽  
Synchronization Accuracy

<p class="0abstract"><span lang="EN-US">A</span><span lang="EN-US">iming at solving the poor</span><span lang="EN-US"> the classical synchronous algorithm stability in wireless sensor network</span><span lang="EN-US"> and high overhead of </span><span lang="EN-US">clock phase offset and frequency offset</span><span lang="EN-US">, </span><span lang="EN-US">a synchronization algorithm (CSMS algorithm) was designed for wireless sensor networks based on frequency offset estimation. The CSMS algorithm used the low overhead phase bias and frequency offset estimation method to improve the synchronization accuracy and stability of the pair nodes. At the same time, a synchronization strategy was built based on layering and broadcast monitoring, which ensured the stability and synchronization accuracy of the algorithm, realized the synchronization with neighbor nodes and root nodes, and optimized the total synchronization cost. Among them, the CSMS algorithm was mainly divided into two stages: level discovery phase, </span><span lang="EN-US">which was used</span><span lang="EN-US"> for generating a layered structure of network; synchronization </span><span lang="EN-US">phase, used to estimate c</span><span lang="EN-US">lock offset and frequency </span><span lang="EN-US">offset between</span><span lang="EN-US"> pairs of nodes</span><span lang="EN-US">.</span><span lang="EN-US"> The experimental results showed that the CSMS algorithm can effectively balance the synchronization energy</span><span lang="EN-US"> consumption</span><span lang="EN-US">, synchronization accuracy and synchronization stability. </span><span lang="EN-US">As a result, it is summed up that </span><span lang="EN-US">dynamic adjustment of the nodes clock deviation</span><span lang="EN-US"> is realized</span><span lang="EN-US">, the long-term stability of synchronization</span><span lang="EN-US"> is ensured</span><span lang="EN-US">, </span><span lang="EN-US">and </span><span lang="EN-US">the precision of synchronization</span><span lang="EN-US"> is improved</span><span lang="EN-US">. </span></p>

scholarly journals An optimization method of clock synchronization for large-scale regional power network based on IEEE 1588

2021 ◽  
Vol 2108 (1) ◽  
pp. 012063
Author(s):  
Yue Zuo ◽  
Xingcai Wang ◽  
Bo Zhang
Keyword(s):  
Large Scale ◽  
Clock Synchronization ◽  
Optimization Method ◽  
Frequency Deviation ◽  
Power Network ◽  
Regional Power ◽  
Time Service ◽  
Ieee 1588 ◽  
Noise Characteristics ◽  
Synchronization Accuracy

Abstract At present, mobile devices generally use GPS, Beidou and other satellite time service methods to obtain time, but the clock synchronization based on IEEE 1588 protocol still has deviation. To solve this problem, a clock synchronization method is proposed to improve IEEE 1588 protocol. Based on the analysis of IEEE 1588 protocol, the clock deviation and frequency deviation which affect the synchronization accuracy are modeled. The second-order Kalman filtering algorithm is used to recursively deduce the clock deviation and frequency deviation, and the Allan variance is used to verify the noise characteristics and constantly correct the clock deviation. Finally, the improved effect is verified by relevant experiments. The results show that the improved system can improve the synchronization accuracy.

Coaches estimation method for the athletes (CEM)

1995 ◽  
Author(s):  
Nagykaldi Csaba ◽  
Manohar Singh Badhan
Keyword(s):  
Estimation Method
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