Fault frequency of catenary is related to meteo-rological conditions. In this work, based on the historical data, catenary fault frequency and weather-related fault rate are introduced to analyse the correlation betwe...Fault frequency of catenary is related to meteo-rological conditions. In this work, based on the historical data, catenary fault frequency and weather-related fault rate are introduced to analyse the correlation between catenary faults and meteorological conditions, and further the effect of meteorological conditions on catenary oper-ation. Moreover, machine learning is used for catenary fault prediction. As with the single decision tree, only a small number of training samples can be classified cor-rectly by each weak classifier, the AdaBoost algorithm is adopted to adjust the weights of misclassified samples and weak classifiers, and train multiple weak classifiers. Finally, the weak classifiers are combined to construct a strong classifier, with which the final prediction result is obtained. In order to validate the prediction method, an example is provided based on the historical data from a railway bureau of China. The result shows that the mapping relation between meteorological conditions and catenary faults can be established accurately by AdaBoost algorithm. The AdaBoost algorithm can accurately predict a catenary fault if the meteorological conditions are provided.展开更多
快速轨道反馈(Fast Orbital Feedback,FOFB)系统是影响高能同步辐射光源(High Energy Photon Source,HEPS)轨道稳定性的重要因素之一,在设计时应尽可能提高FOFB系统的有效反馈带宽。基于该需求,为HEPS的FOFB系统设计了两层环路集中计算...快速轨道反馈(Fast Orbital Feedback,FOFB)系统是影响高能同步辐射光源(High Energy Photon Source,HEPS)轨道稳定性的重要因素之一,在设计时应尽可能提高FOFB系统的有效反馈带宽。基于该需求,为HEPS的FOFB系统设计了两层环路集中计算式的系统网络拓扑结构,并在此基础上设计完成了FOFB系统信号传输链路的可编程阵列逻辑(Field Programmable Gate Array,FPGA)固件算法逻辑,内容包括束流位置获取、环路数据传输、FOFB算法、电源控制接口以及系统测试等多个部分。经实验室测试验证,当前结构下的FOFB系统总延迟时间约为140μs,满足HEPS装置对FOFB系统有效反馈带宽的需求。展开更多
遥感卫星图像数据量的高速增长,以及遥感卫星搭载的相机不同工作模式下产生的数据差异化处理的需求,为星间数据处理带来了巨大挑战。针对星载Gbit·s-1级高速数据收发及文件缓存等星间数据处理面临的问题,以百兆每秒级星载高速接收...遥感卫星图像数据量的高速增长,以及遥感卫星搭载的相机不同工作模式下产生的数据差异化处理的需求,为星间数据处理带来了巨大挑战。针对星载Gbit·s-1级高速数据收发及文件缓存等星间数据处理面临的问题,以百兆每秒级星载高速接收缓存系统为切入点,以遥感卫星数据处理的发展为依据,在分析SerDes传输原理的基础上,采用模型仿真和工程验证的方法,制定了高速串行数据链路层传输协议SSLLP(Satellite Serial Link Layer Protocol)和类文件化高速缓存的策略。在硬件设计和软件开发的基础上,最终完成了具备处理入口速率3.2 Gbit·s^(-1)并能以类文件化的方式缓存64个数据文件的星载数据处理单元的工程实现。测试结果表明,基于SSLLP的高速串行数据接收正确,缓存策略有效,系统高效可靠。该设计已在某型号任务中取得在轨验证,为星载高速串行数据处理系统提供了参考。展开更多
基金supported by the Scientific and Technological Research and Development Program of China Railway Corporation under Grant N2018G023by the Science and Technology Projects of Sichuan Province under Grants 2018RZ0075
文摘Fault frequency of catenary is related to meteo-rological conditions. In this work, based on the historical data, catenary fault frequency and weather-related fault rate are introduced to analyse the correlation between catenary faults and meteorological conditions, and further the effect of meteorological conditions on catenary oper-ation. Moreover, machine learning is used for catenary fault prediction. As with the single decision tree, only a small number of training samples can be classified cor-rectly by each weak classifier, the AdaBoost algorithm is adopted to adjust the weights of misclassified samples and weak classifiers, and train multiple weak classifiers. Finally, the weak classifiers are combined to construct a strong classifier, with which the final prediction result is obtained. In order to validate the prediction method, an example is provided based on the historical data from a railway bureau of China. The result shows that the mapping relation between meteorological conditions and catenary faults can be established accurately by AdaBoost algorithm. The AdaBoost algorithm can accurately predict a catenary fault if the meteorological conditions are provided.
文摘快速轨道反馈(Fast Orbital Feedback,FOFB)系统是影响高能同步辐射光源(High Energy Photon Source,HEPS)轨道稳定性的重要因素之一,在设计时应尽可能提高FOFB系统的有效反馈带宽。基于该需求,为HEPS的FOFB系统设计了两层环路集中计算式的系统网络拓扑结构,并在此基础上设计完成了FOFB系统信号传输链路的可编程阵列逻辑(Field Programmable Gate Array,FPGA)固件算法逻辑,内容包括束流位置获取、环路数据传输、FOFB算法、电源控制接口以及系统测试等多个部分。经实验室测试验证,当前结构下的FOFB系统总延迟时间约为140μs,满足HEPS装置对FOFB系统有效反馈带宽的需求。
文摘遥感卫星图像数据量的高速增长,以及遥感卫星搭载的相机不同工作模式下产生的数据差异化处理的需求,为星间数据处理带来了巨大挑战。针对星载Gbit·s-1级高速数据收发及文件缓存等星间数据处理面临的问题,以百兆每秒级星载高速接收缓存系统为切入点,以遥感卫星数据处理的发展为依据,在分析SerDes传输原理的基础上,采用模型仿真和工程验证的方法,制定了高速串行数据链路层传输协议SSLLP(Satellite Serial Link Layer Protocol)和类文件化高速缓存的策略。在硬件设计和软件开发的基础上,最终完成了具备处理入口速率3.2 Gbit·s^(-1)并能以类文件化的方式缓存64个数据文件的星载数据处理单元的工程实现。测试结果表明,基于SSLLP的高速串行数据接收正确,缓存策略有效,系统高效可靠。该设计已在某型号任务中取得在轨验证,为星载高速串行数据处理系统提供了参考。
