Time synchronization(TS)is crucial for ensuring the secure and reliable functioning of the distribution power Internet of Things(IoT).Multi-clock source time synchronization(MTS)has significant advantages of high reli...Time synchronization(TS)is crucial for ensuring the secure and reliable functioning of the distribution power Internet of Things(IoT).Multi-clock source time synchronization(MTS)has significant advantages of high reliability and accuracy but still faces challenges such as optimization of the multi-clock source selection and the clock source weight calculation at different timescales,and the coupling of synchronization latency jitter and pulse phase difference.In this paper,the multi-timescale MTS model is conducted,and the reinforcement learning(RL)and analytic hierarchy process(AHP)-based multi-timescale MTS algorithm is designed to improve the weighted summation of synchronization latency jitter standard deviation and average pulse phase difference.Specifically,the multi-clock source selection is optimized based on Softmax in the large timescale,and the clock source weight calculation is optimized based on lower confidence bound-assisted AHP in the small timescale.Simulation shows that the proposed algorithm can effectively reduce time synchronization delay standard deviation and average pulse phase difference.展开更多
Power Line Communications-Artificial Intelligence of Things(PLC-AIo T)combines the low cost and high coverage of PLC with the learning ability of Artificial Intelligence(AI)to provide data collection and transmission ...Power Line Communications-Artificial Intelligence of Things(PLC-AIo T)combines the low cost and high coverage of PLC with the learning ability of Artificial Intelligence(AI)to provide data collection and transmission capabilities for PLC-AIo T devices in smart parks.With the development of smart parks,their emerging services require secure and accurate time synchronization of PLC-AIo T devices.However,the impact of attackers on the accuracy of time synchronization cannot be ignored.To solve the aforementioned problems,we propose a tampering attack-aware Deep Q-Network(DQN)-based time synchronization algorithm.First,we construct an abnormal clock source detection model.Then,the abnormal clock source is detected and excluded by comparing the time synchronization information between the device and the gateway.Finally,the proposed algorithm realizes the joint guarantee of high accuracy and low delay for PLC-AIo T in smart parks by intelligently selecting the multi-clock source cooperation strategy and timing weights.Simulation results show that the proposed algorithm has better time synchronization delay and accuracy performance.展开更多
针对北斗卫星导航系统(BeiDou Navigation Satellite System,BDS)精密单点定位(precise point positioning,PPP)服务PPP-B2b在同一时刻可用于PPP的卫星数量有限,以及其实时钟差解算评估研究较少的问题,本文提出了一种基于BDS PPP-B2b与G...针对北斗卫星导航系统(BeiDou Navigation Satellite System,BDS)精密单点定位(precise point positioning,PPP)服务PPP-B2b在同一时刻可用于PPP的卫星数量有限,以及其实时钟差解算评估研究较少的问题,本文提出了一种基于BDS PPP-B2b与Galileo高精度服务(high accuracy service,HAS)融合的改进方案,并对其实时钟差解算性能进行了系统性评估.该方法利用两个卫星系统的PPP服务改正数进行融合,显著提升了同一时刻内可用卫星数量.相较于单一PPP-B2b服务方案,在钟差解算的精度和稳定性方面具有明显提升.同时,实验结果表明,该方法在经过一定时间的收敛后,其性能优于德国波兹坦地学研究中心(German Research Centre for Geosciences,GFZ)提供的超快速(UTL)产品.因此,本文不仅为提高PPP-B2b服务的实际应用能力提供了有效途径,也为多系统融合下的实时时间解算方法设计与性能优化提供了新的思路和实验验证.展开更多
近年来应用于中高能核物理实验的先进前端读出专用集成电路(application specific integrated circuit,ASIC)芯片呈现出越来越强的数字化趋势,可提高系统的集成度并降低功耗。论文研制了一种高计数率多通道时间测量与串行读出电路(high-...近年来应用于中高能核物理实验的先进前端读出专用集成电路(application specific integrated circuit,ASIC)芯片呈现出越来越强的数字化趋势,可提高系统的集成度并降低功耗。论文研制了一种高计数率多通道时间测量与串行读出电路(high-count rate multi-channel time measurement and serial readout circuit,HMTRC),可实现核事件去稀疏化、去随机化的读出。该电路主要包括了基于时钟分相技术的时间数字转化器、控制器、先进先出存储器和基于令牌环逻辑的轮询读出模块。HMTRC已被集成到一款自研的16通道前端读出ASIC芯片中,可测量和储存时间信息,并利用数字驱动的前端读出架构实现时间与能量信息同步读出。测试表明,时间分辨率好于2 ns,功能符合预期。展开更多
基金supported by Science and Technology Project of China Southern Power Grid Company Limited under Grant Number 036000KK52200058(GDKJXM20202001).
文摘Time synchronization(TS)is crucial for ensuring the secure and reliable functioning of the distribution power Internet of Things(IoT).Multi-clock source time synchronization(MTS)has significant advantages of high reliability and accuracy but still faces challenges such as optimization of the multi-clock source selection and the clock source weight calculation at different timescales,and the coupling of synchronization latency jitter and pulse phase difference.In this paper,the multi-timescale MTS model is conducted,and the reinforcement learning(RL)and analytic hierarchy process(AHP)-based multi-timescale MTS algorithm is designed to improve the weighted summation of synchronization latency jitter standard deviation and average pulse phase difference.Specifically,the multi-clock source selection is optimized based on Softmax in the large timescale,and the clock source weight calculation is optimized based on lower confidence bound-assisted AHP in the small timescale.Simulation shows that the proposed algorithm can effectively reduce time synchronization delay standard deviation and average pulse phase difference.
基金supported by the Science and Technology Project of the State Grid Corporation of China under Grant Number 5400202199541A-0-5-ZN。
文摘Power Line Communications-Artificial Intelligence of Things(PLC-AIo T)combines the low cost and high coverage of PLC with the learning ability of Artificial Intelligence(AI)to provide data collection and transmission capabilities for PLC-AIo T devices in smart parks.With the development of smart parks,their emerging services require secure and accurate time synchronization of PLC-AIo T devices.However,the impact of attackers on the accuracy of time synchronization cannot be ignored.To solve the aforementioned problems,we propose a tampering attack-aware Deep Q-Network(DQN)-based time synchronization algorithm.First,we construct an abnormal clock source detection model.Then,the abnormal clock source is detected and excluded by comparing the time synchronization information between the device and the gateway.Finally,the proposed algorithm realizes the joint guarantee of high accuracy and low delay for PLC-AIo T in smart parks by intelligently selecting the multi-clock source cooperation strategy and timing weights.Simulation results show that the proposed algorithm has better time synchronization delay and accuracy performance.
文摘针对北斗卫星导航系统(BeiDou Navigation Satellite System,BDS)精密单点定位(precise point positioning,PPP)服务PPP-B2b在同一时刻可用于PPP的卫星数量有限,以及其实时钟差解算评估研究较少的问题,本文提出了一种基于BDS PPP-B2b与Galileo高精度服务(high accuracy service,HAS)融合的改进方案,并对其实时钟差解算性能进行了系统性评估.该方法利用两个卫星系统的PPP服务改正数进行融合,显著提升了同一时刻内可用卫星数量.相较于单一PPP-B2b服务方案,在钟差解算的精度和稳定性方面具有明显提升.同时,实验结果表明,该方法在经过一定时间的收敛后,其性能优于德国波兹坦地学研究中心(German Research Centre for Geosciences,GFZ)提供的超快速(UTL)产品.因此,本文不仅为提高PPP-B2b服务的实际应用能力提供了有效途径,也为多系统融合下的实时时间解算方法设计与性能优化提供了新的思路和实验验证.
文摘近年来应用于中高能核物理实验的先进前端读出专用集成电路(application specific integrated circuit,ASIC)芯片呈现出越来越强的数字化趋势,可提高系统的集成度并降低功耗。论文研制了一种高计数率多通道时间测量与串行读出电路(high-count rate multi-channel time measurement and serial readout circuit,HMTRC),可实现核事件去稀疏化、去随机化的读出。该电路主要包括了基于时钟分相技术的时间数字转化器、控制器、先进先出存储器和基于令牌环逻辑的轮询读出模块。HMTRC已被集成到一款自研的16通道前端读出ASIC芯片中,可测量和储存时间信息,并利用数字驱动的前端读出架构实现时间与能量信息同步读出。测试表明,时间分辨率好于2 ns,功能符合预期。
