scholarly journals High Precision Clock Bias Prediction Model in Clock Synchronization System

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Zan Liu ◽  
Xihong Chen ◽  
Jin Liu ◽  
Chenglong Li
Keyword(s):  
Distributed System ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Signal Transmission ◽  
Time Signal ◽  
System Clock ◽  
Prediction Module ◽  
Equipment Failures ◽  
Improved Model ◽  
Clock Calibration

Time synchronization is a fundamental requirement for many services provided by a distributed system. Clock calibration through the time signal is the usual way to realize the synchronization among the clocks used in the distributed system. The interference to time signal transmission or equipment failures may bring about failure to synchronize the time. To solve this problem, a clock bias prediction module is paralleled in the clock calibration system. And for improving the precision of clock bias prediction, the first-order grey model with one variable (GM(1,1)) model is proposed. In the traditional GM(1,1) model, the combination of parameters determined by least squares criterion is not optimal; therefore, the particle swarm optimization (PSO) is used to optimize GM(1,1) model. At the same time, in order to avoid PSO getting stuck at local optimization and improve its efficiency, the mechanisms that double subgroups and nonlinear decreasing inertia weight are proposed. In order to test the precision of the improved model, we design clock calibration experiments, where time signal is transferred via radio and wired channel, respectively. The improved model is built on the basis of clock bias acquired in the experiments. The results show that the improved model is superior to other models both in precision and in stability. The precision of improved model increased by 66.4%~76.7%.

Synchronization Design for Multi-Channel Data Acquisition System

2013 ◽  
Vol 333-335 ◽  
pp. 472-479
Author(s):  
Jian Fei An ◽  
Ke Zhu Song ◽  
Lin Feng Shang ◽  
Jun Feng Yang
Keyword(s):  
Data Acquisition ◽  
Clock Synchronization ◽  
Great Influence ◽  
Channel Structure ◽  
Seismic Exploration ◽  
Large Area ◽  
Clock Data Recovery ◽  
System Clock ◽  
Recovery Technique ◽  
Synchronization Scheme

In land seismic data acquisition systems, as seismic exploration goes towards to cover large area, a multi-channel structure is needed. In such systems, synchronization is very important, which has great influence on data acquisition and transmission. In this paper, a clock synchronization scheme for seismic exploration is proposed. In the scheme, LVDS serial transmission is used so that the whole system clocks can be made to have the same frequency through clock data recovery technique. Moreover, to compensate the effect caused by transmission delay, an effective algorithm based on PLL phase locked and FPGA logic is proposed in this scheme. The test results show that this scheme meets the system clock synchronization requirements well with the error precision less than 1ns, which fully demonstrates the feasibility and reliability of the scheme. The scheme proposed here can be used in related systems which require clock synchronization.

scholarly journals An Efficient Algorithm for Partial Discharge Localization in High-Voltage Systems Using Received Signal Strength

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4000 ◽  
Author(s):  
Umar F. Khan ◽  
Pavlos I. Lazaridis ◽  
Hamd Mohamed ◽  
Ricardo Albarracín ◽  
Zaharias D. Zaharis ◽  
...  
Keyword(s):  
High Voltage ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Human Life ◽  
Partial Discharge ◽  
Signal Strength ◽  
Received Signal Strength ◽  
Time Of Arrival ◽  
Localization Algorithm ◽  
Require Time

The term partial discharge (PD) refers to a partial bridging of insulating material between electrodes that sustain an electric field in high-voltage (HV) systems. Long-term PD activity can lead to catastrophic failures of HV systems resulting in economic, energy and even human life losses. Such failures and losses can be avoided by continuously monitoring PD activity. Existing techniques used for PD localization including time of arrival (TOA) and time difference of arrival (TDOA), are complicated and expensive because they require time synchronization. In this paper, a novel received signal strength (RSS) based localization algorithm is proposed. The reason that RSS is favoured in this research is that it does not require clock synchronization and it only requires the energy of the received signal rather than the PD pulse itself. A comparison was made between RSS based algorithms including a proposed algorithm, the ratio and search and the least squares algorithm to locate a PD source for nine different positions. The performance of the algorithms was evaluated by using two field scenarios based on seven and eight receiving nodes, respectively. The mean localization error calculated for two-field-trial scenarios show, respectively, 1.80 m and 1.76 m for the proposed algorithm for all nine positions, which is the lowest of the three algorithms.

The Hardware Design of Measurement System of Transmission Lines Based on Wireless Communication

2015 ◽  
Vol 1092-1093 ◽  
pp. 366-369
Author(s):  
Shu Min Sun ◽  
Wen Juan Jiang ◽  
Yu Meng ◽  
Yan Cheng
Keyword(s):  
Wireless Communication ◽  
Data Storage ◽  
Measurement System ◽  
Transmission Lines ◽  
High Speed ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Report Generation ◽  
Test Efficiency ◽  
Synchronization Module

A set of measurement system for the testing of transmission lines, composing of wireless center station, wireless current acquisition and transmission nodes, wireless voltage acquisition and transmission node, was designed, which was based on wireless communication. The high speed wireless bridge working at 2.4GHz together with the clock synchronization module based on the IEEE1588 communicating protocol were both employed for the communication and time synchronization separately. The measurement system has data storage, waveform display, data analysis, automatic report generation and other functions. The measurement system can greatly reduced arrangement of cables, thereafter improved the test efficiency.

Designs for Synchronous Data Acquisition of a Distributed System

2012 ◽  
Vol 239-240 ◽  
pp. 869-872
Author(s):  
Zuo Xi Tian ◽  
Feng Yu ◽  
Zeng Wu Liu
Keyword(s):  
Data Acquisition ◽  
Distributed System ◽  
Control Unit ◽  
Time Base ◽  
Time Signal ◽  
Centralized Control ◽  
Distributed Sensor ◽  
Network Time ◽  
Data Acquisition Module ◽  
C Center

To resolve the problem of acquiring multi sensors signals synchronously in a distributed system, a project of distributed synchronous data acquisition based network time server was designed. The system comprised multi distributed sensor units, a centralized control unit and D&C (display and control) center. Each sensor unit was equipped with a data acquisition module. All data from sensor units were concentrated and sent to the D&C center, and the D&C center implemented power supply and management of sensor units via the centralized control unit. To synchronize the data acquisition modules, a network time server was employed in the D&C center. It received standard time information from GPS and outputted the time signal with DCF77-encoding. Each data acquisition module received and decoded DCF77 time signal, obtaining absolute time and synchronizing its time base. Above project was applied successfully in a system comprising 20 distributed sensor units. The results prove the designs feasible.

Pulse-Coupled Synchronization Protocol and Its Optimized Algorithm for Wireless Sensor Networks

2021 ◽  
Author(s):  
Chao Shi ◽  
Wei Zhang ◽  
Lihong Zhang
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Coupling Coefficient ◽  
Time Synchronization ◽  
Wireless Sensor ◽  
Time Signal ◽  
Data Simulation ◽  
Pulse Waves ◽  
Time Information ◽  
Synchronization Protocol

This paper proposed a pulse-coupled synchronization protocol for wireless sensor networks. The time information of the node can be encoded at the Mac layer and then sent and received in the form of pulse waves. During the exchange of time information between a pair of nodes, one node will adjust its own clock information according to certain rules after receiving the pulse time signal of the other node. This process is repeated in the entire wireless sensor network. Under certain environmental and estimated parameter conditions, all nodes in the network can finally converge to a coherent frequency and phase, thus realizing time synchronization. The relationship between time synchronization and coupling coefficient was proved theoretically, and the optimal coupling coefficient was derived. An optimized algorithm was proposed after the optimization of the protocol. Finally, the correctness of the proposed protocol and its optimized algorithm was verified by data simulation.

scholarly journals Overview of Time Synchronization for IoT Deployments: Clock Discipline Algorithms and Protocols

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5928
Author(s):  
Hüseyin Yiğitler ◽  
Behnam Badihi ◽  
Riku Jäntti
Keyword(s):  
Time Synchronization ◽  
Clock Synchronization ◽  
Constrained Systems ◽  
Clock Model ◽  
Network Time ◽  
Expected Performance ◽  
The Everyday ◽  
Network Time Protocol ◽  
Synchronization Problems ◽  
Constrained Devices

Internet of Things (IoT) is expected to change the everyday life of its users by enabling data exchanges among pervasive things through the Internet. Such a broad aim, however, puts prohibitive constraints on applications demanding time-synchronized operation for the chronological ordering of information or synchronous execution of some tasks, since in general the networks are formed by entities of widely varying resources. On one hand, the existing contemporary solutions for time synchronization, such as Network Time Protocol, do not easily tailor to resource-constrained devices, and on the other, the available solutions for constrained systems do not extend well to heterogeneous deployments. In this article, the time synchronization problems for IoT deployments for applications requiring a coherent notion of time are studied. Detailed derivations of the clock model and various clock relation models are provided. The clock synchronization methods are also presented for different models, and their expected performance are derived and illustrated. A survey of time synchronization protocols is provided to aid the IoT practitioners to select appropriate components for a deployment. The clock discipline algorithms are presented in a tutorial format, while the time synchronization methods are summarized as a survey. Therefore, this paper is a holistic overview of the available time synchronization methods for IoT deployments.

Research on Key Technology of Time Synchronization Network in Electric Power System

2015 ◽  
Vol 1092-1093 ◽  
pp. 332-336
Author(s):  
Hong Zhang Xiong ◽  
Xi Chen ◽  
Ling Teng ◽  
Qiang Gao ◽  
Yang Wang
Keyword(s):  
High Precision ◽  
High Performance ◽  
Large Scale ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Electric Power System ◽  
Normal Operation ◽  
Synchronization System ◽  
Performance Time ◽  
Precision Clock

Development of intelligent grid have increasing demands for time synchronization, high precision, large scale, high performance time synchronization system has become necessary guarantee for the normal operation of the power grid. This article introduced the composition of the time synchronization system, discusses the IEEE1588 implementation of high precision clock synchronization principle and SDH data transmission principle, analysis of the PTP protocol for transmission through the principle of the SDH E1 line, gives the networking scheme of PTP over the E1 way, which meet the precision requirement of 1 us.

Design and Implementation of IEEE 1588 High Precision Clock Synchronization Based on GPS Time Service

2012 ◽  
Vol 532-533 ◽  
pp. 292-296 ◽  
Author(s):  
Kang Wang ◽  
Yong Hui Hu ◽  
Zai Min He ◽  
Hong Jiao Ma
Keyword(s):  
High Precision ◽  
Time Synchronization ◽  
Clock Synchronization ◽  
Time Service ◽  
Ieee 1588 ◽  
Design And Implementation ◽  
Nanosecond Range ◽  
Application Fields ◽  
Timing Requirement ◽  
Precision Clock

In view of PTP high precise timing requirement for many application fields, GPS time service is provided with the advantages of high precision and high stabilization. The principle and timescale of PTP based on GPS are analyzed and discussed. And then a PTP time synchronization platform with GPS-based UTC time is designed and implemented, the correlative key design flowchart is described as well. Finally, the paper gives the experiment results, which show the time synchronization accuracies can reach nanosecond range.

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