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synchronization algorithm of Ultra Wideband Communication

Synchronization Algorithm of Ultra Wideband Communication

2011 International Conference on Electronic & Mechanical Engineering and Information Technology(EMEIT 2011)(2011年机电工程与信息技术国际会议)

作者： Nuan Feng Yong Chen Polytechnic school of Shenyang Ligong University Fushun china

In this paper, the timing synchronization is studied and proposed a synchronization acquisition algorithm based on least-squares estimation. The advantages of the poposed algorithm is that it can reach a compromise between complexity and synchronization performance and also obtain good synchronization precision under certain SNR (Signal to Noise Ratio). Takes Time-Hopping Ultra-Wideband Pulse-Amplitudemodulate signal system as an example, simulation results have demonstrated the feasibility of the proposed method and verified the theoretical analysis.

关键词： ultra wideband synchronization algorithm acquisition.

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Thermal flutter prediction at trajectory points of a hypersonic vehicle based on aerothermal synchronization algorithm

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AEROSPACE SCIENCE AND TECHNOLOGY 2019年 94卷 105381-000页

作者： Guo, Tongqing Shen, Ennan Lu, Zhiliang Zhou, Di Wu, Jiangpeng Nanjing Univ Aeronaut & Astronaut Key Lab Unsteady Aerodynam & Flow Control Minist Ind & Informat Technol Yudao St 29 Nanjing 210016 Jiangsu Peoples R China Shenyang Aircraft Design & Res Inst Shenyang 110035 Liaoning Peoples R China

Due to orders of magnitude differences in time scale between structural heat transfer and aeroelastic responses, one-way aerothermal-aeroelastic coupling is adopted to develop a thermal flutter prediction method for a hypersonic vehicle operating along a desired trajectory. In view of the strong dependency of the heat transfer process on the unsteady hypersonic trajectory, an aerothermal synchronization algorithm is established in a non-inertial frame of reference by formulating the governing equations of fluid flow and heat transfer into a unified form. Then the heated free-vibration frequencies and mode shapes are calculated at each trajectory point by using a finite-element analysis. Consequently, the flutter computations are performed on the transiently heated structure at each trajectory point by utilizing a coupled computational fluid dynamics (CFD)/computational structural dynamics (CSD) method. Because of the mass dissimilarity caused by directly increasing the dynamic pressure of a compressible flow, the technique of variable stiffness is introduced to evaluate the flutter dynamic pressure at the point of mass similarity and the stiffness margin of flutter. The present method is applied to the thermal flutter computations of a hypersonic all-movable rudder operating along a given trajectory. The computed temperature differences between the synchronization and conventional partitioned methods, and the significant effects of aerodynamic heating on the structural modes and the flutter characteristics are analyzed in detail. (C) 2019 Elsevier Masson SAS. All rights reserved.

关键词： Hypersonic vehicle Trajectory Thermal flutter Aerothermal synchronization algorithm CFD/CSD

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Research on virtual flux oriented synchronization algorithm for three-phase grid voltages

Research on virtual flux oriented synchronization algorithm ...

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2018 3rd International Conference on Automation,Mechanical Control and Computational Engineering(AMCCE 2018)

作者： Lu Wang Department of Mathematics and Information Engineering Chongqing University of Education

To deal with the synchronization of three-phase grid-connected converters, a synchronization algorithm based on virtual flux orientation is proposed in this paper. By introducing a low-pass filter and a high-pass filter, the orthogonal components of the virtual flux under the αβ stationary coordinate frame that αψ and βψ corresponding to the three-phase voltages can be calculated, and a decoupling compensation is adopted to eliminate the influence of these filters on the fundamental component of virtual flux. Then the phase angle of the three-phase grid voltages can be derived directly according to αψ and βψ, without any rotating coordinate transformation. The simulation results show that this algorithm can extract the phase angle of the fundamental component of grid voltage quickly and accurately under unideal power grid conditions, and it also has strong ability of frequency adaptation.

关键词： three-phase grid voltages synchronization algorithm virtual flux orientation filter decoupling compensation

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Research and Implementation of Time synchronization algorithm based on Frequency Adjustment in Distributed System

Research and Implementation of Time Synchronization Algorith...

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2007 IEEE International Conference on Automation and Lofistics

作者： Peng He Na Yi Biqing Wang Bin Zhao Information Technology Center Three Gorges University Yichang Hubei China College of Electrical & Information Three Gorges University Yichang Hubei China

ISBN: (纸本)9781424415304;1424415306

Time synchronization is one of core technologies in Distributed Systems and Communication Fields. The “Network Time Protocol” (NTP) is the current widely accepted standard for synchronizing clocks over the Internet. NTP uses a hierarchical scheme in order to synchronize the clocks in the network. It mainly adopts a phase-locked loop technique to adjust the local clock. This paper develops a time synchronization algorithm based on frequency adjustment in distributed system, which has a better performance compared with current algorithm, which uses the method of phase adjusting time. Under the same accuracy requirement, the algorithm has much less time requests to the NTP server and higher stability in performance, which decreases a lot on the load of server. This algorithm is more effective and would have preferable value in application.

关键词： NTP frequency adjustment distributed system synchronization algorithm

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Reseach of Time synchronization algorithm based on IEEE1588 in Electric Power System

Reseach of Time Synchronization Algorithm based on IEEE1588 ...

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International Conference on Control Engineering and Communication Technology

作者： Bin Zhao Min Zhang Jie Ji Peng Zhai Department of Computer Science University of Jining Qufu China Jining vocational Technology College Jining China

ISBN: (纸本)9781467344999

For the high accuracy synchronization requirement of IEC61850 based digital substation, to apply a combination of time synchronization scheme to Substation Automation System (SAS), PTP(pricision time synchronization protocol) is adopted between bay level and process level equipment;the paper presents a method of combination of adjusted frequency and adjusted phase to achieve precision synchronization based on principle of PTP. The result of the experiment shows the algorithm is more effective.

关键词： IEEE1588 time synchronization IEC61850 synchronization algorithm

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An Improved Time synchronization algorithm on 1000BASE-T Ethernet

An Improved Time Synchronization Algorithm on 1000BASE-T Eth...

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IEEE Nuclear Science Symposium and Medical Imaging Conference

作者： Ferenc Nagy József Imrek Gyula Hegyesi Iván Valastyán József Molnár Institute of Nuclear Research Hungarian Academy of Sciences Debrecen Hungary Magyar Tudomanyos Akademia Atommagkutato Intezet Debrecen HajdÃº-Bihar HU

Using 1000BASE-T Ethernet for data acquisition with all -clients connecting to the same switch, the 125Mhz Ethernet clock recovered by each client can serve as the shared synchronous clock. In order to synchronize the time stamp counters of the clients, we used special synchronizing broadcast messages. However, using these broadcast packets did not perfectly synchronize the time stamp values: a systematic offset and some random "jitter" remained. In our present paper we describe an algorithm that eliminates the non-deterministic part of the time stamp offset approximating the theoretical 8 ns accuracy. Our algorithm is based on identifying the left-edge of the client Packet Delay histogram and capable of aligning the client times with an accuracy of 16 ns. The reliability of the method was tested and proved by a long term measurement.

关键词： 1000BASE-T synchronization algorithm data acquisition

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Research on synchronization Control algorithm of Gantry-Type Motion Platform Based on IC Package 20

Research on Synchronization Control Algorithm of Gantry-Type...

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20th International Conference on Electronic Packaging Technology (ICEPT)

作者： He, Yunbo Li, Zhanchao Gao, Jian Cui, Chengqiang Guangdong Univ Technol Sch Electromech Engn State Key Lab Precis Elect Mfg Technol & Equipmen Guangzhou Peoples R China

ISBN: (纸本)9781728150642

As global semiconductor gradually develop into the post-Moore era, the status of microelectronic packaging technology in the IC industry is becoming increasingly prominent, and the requirements for high precision and high speed of microelectronic packaging equipment are also increasing. The gantry type motion platform is widely used in chip packaging. However, due to the mechanical coupling of the beam between the two linear motors of the gantry type motion platform, the system positioning accuracy and synchronization performance are seriously affected. In this paper, a self-made gantry motion platform is taken as the research object, and a cross-coupling synchronization algorithm based on fuzzy feedforward controller is proposed to realize the synchronous control of the system, including a fuzzy feedforward controller and a compensation controller based on cross-coupling principle. The cross-coupling controller takes the speed difference of two linear motors as the input signals, which compensates to the speed loop after being adjusted by the PI controller. The simulation results show that the cross-coupling synchronization algorithm based on fuzzy feedforward control can ensure the positioning accuracy, the response speed is faster, the anti-interference ability is stronger, and the synchronous follow performance is good, which basically meets the high-speed and high-precision requirements of the microelectronic packaging industry.

关键词： gantry motion platform fuzzy control feedforward controller synchronization algorithm

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The Statistics of Computer Clocks and the Design of synchronization algorithms

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JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY 2020年 125卷 125008页

作者： Levine, Judah NIST Time & Frequency Div Boulder CO 80305 USA

In this study, I used standard statistical tools (such as the various forms of the two-sample Allan variance) to characterize the clocks in computers, and I show how the results of this study are used to design algorithms to synchronize the computer clocks. These synchronization algorithms can be used to synchronize the time of a computer to a local reference clock or to a remote server. The algorithms by themselves are not intended to be a simple replacement for software that implements the Network Time Protocol (NTP) or any other similar application. Instead, they describe the statistical principles that should be used to design an algorithm to synchronize any computer clock by using data from any external reference received in any format. These algorithms have been used to synchronize the clocks of the computers that support the Internet Time Service operated by the National Institute of Standards and Technology (NIST), and I illustrate the performance of the algorithm with real-time data from these servers. In addition to presenting the design principles of the algorithm, I illustrate the principles with two specific examples: synchronizing a computer clock to a local reference signal, and the design of a synchronization process that is based on time-difference data received from a remote server over the public Internet. The message exchange between the local system and the remote server in this configuration is realized in NTP format, but that is not a fundamental requirement.

关键词： computer clocks frequency-lock loop network time phase-lock loop synchronization algorithm two-sample variance

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An Integrated synchronization and Control Strategy for Parallel-Operated Inverters Based on V-I Droop Characteristics

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IEEE TRANSACTIONS ON POWER ELECTRONICS 2022年第5期37卷 5373-5384页

作者： Cao, Wenyuan Han, Minxiao Zhang, Xiahui Guan, Yajuan Guerrero, Josep M. Vasquez, Juan C. North China Elect Power Univ Sch Elect & Elect Engn Beijing 102206 Peoples R China Aalborg Univ Dept Energy Technol DK-9220 Aalborg Denmark

Voltage-current (V-I) droop control is becoming a promising alternative to achieve proper power sharing among the parallel-operated voltage-sourced inverters (VSIs). Compared with the conventional droop control, this method has a simpler structure and a better dynamic performance because it saves the power loop (including the low-pass filters). However, due to the absence of the power loop related to the system frequency, the synchronization of VSIs becomes an intractable issue. To tackle this, a communication-free algorithm to synchronize and control the VSIs is proposed. Initially, the principle of V-I droop control is presented straightforwardly based on the virtual impedance. Then, a synchronization algorithm is incorporated into the V-I droop controller for accurate power sharing. This algorithm adaptively adjusts the phase step of each VSI according to the phase differences between VSI and the ac bus. In this way, the phase differences of each VSI to the ac bus eventually converge to an identical value, thus realizing the synchronization of VSIs. A detailed parameter design method is also implemented considering both system stability and power quality. Finally, the proposed strategy is validated experimentally using a three-parallel-VSIs system.

关键词： synchronization Impedance Voltage control Power harmonic filters Inverters Resistance Frequency control synchronization algorithm virtual impedance voltage-current droop voltage-sourced inverter

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Revisiting the cutting of the firing squad synchronization

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NATURAL COMPUTING 2018年第3期17卷 455-465页

作者： Dimitriadis, Antonios Kutrib, Martin Sirakoulis, Georgios Ch. Democritus Univ Thrace Dept Elect & Comp Engn Xanthi Greece Univ Giessen Inst Informat Arndtstr 2 D-35392 Giessen Germany

Various synchronization algorithms have been introduced in literature during the last decades to deal with the firing squad synchronization problem on cellular automata (CA). Among others defective CA algorithms, where the CA cell is able to transmit information without previous processing, have been also presented. In our case, originating from the classical Mazoyer's paper, where a minimum-time solution is presented with 6 states, a one-dimensional CA where one cell may permanently fail is presented. In the proposed algorithm, the defective cell can neither process nor transmit information any longer, while it is considered that such dynamic defects may become apparent in any time step of computation. A thorough analysis of the synchronization, in terms of location and time at which cell fails, for the cells found in both sides of defective cell is delivered to decipher the corresponding maximal possible number of synchronized cells in each part of the cut, due to defect, CA array. The proposed algorithm is properly extended to consider more than one defective cells that may occur in the under study one-dimensional CA. Based on the aforementioned analysis, we provide the generalization of synchronization with multiple totally defective cells, while application examples of the generalized CA algorithm in case of two defective cells are also presented. Finally, another intriguing aspect refers to handling of states that could be tentatively characterized as unknown, in a confrontation similar to the previous defective state but also different, since now this(these) cell(s) are not stated as faulty but unknown. As a result, a new one-dimensional CA with less states, compared to the previous CA defective algorithms, able to synchronize the maximal possible number of cells in each part occurs.

关键词： Defective cellular automata Firing squad synchronization problem Fault tolerance synchronization algorithm Multiple totally defective cells Unknown states

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