The implementation of Intelligent Transport System (ITS) technology is expected to significantly improve road safety and traffic efficiency. One of the key components of ITS is precise vehicle positioning. Positioning...The implementation of Intelligent Transport System (ITS) technology is expected to significantly improve road safety and traffic efficiency. One of the key components of ITS is precise vehicle positioning. Positioning with decimetre to sub-metre accuracy is a fundamental capability for self-driving, and other automated applications. Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) is an attractive positioning approach for ITS due to its relatively low-cost and flexibility. However, GNSS PPP is vulnerable to several effects, especially those caused by the challenging urban environments, where the ITS technology is most likely needed. To meet the high integrity requirements of ITS applications, it is necessary to carefully analyse potential faults and failures of PPP and to study relevant integrity monitoring methods. In this paper an overview of vulnerabilities of GNSS PPP is presented to identify the faults that need to be monitored when developing PPP integrity monitoring methods. These vulnerabilities are categorised into different groups according to their impact and error sources to assist integrity fault analysis, which is demonstrated with Failure Modes and Effects Analysis (FMEA) and Fault Tree Analysis (FTA) methods. The main vulnerabilities are discussed in detail, along with their causes, characteristics, impact on users, and related mitigation methods. In addition, research on integrity monitoring methods used for accounting for the threats and faults in PPP for ITS applications is briefly reviewed. Both system-level (network-end) and user-level (user-end) integrity monitoring approaches for PPP are briefly discussed, focusing on their development and the challenges in urban scenarios. Some open issues, on which further efforts should focus, are also identified.展开更多
针对当前城市轨道交通(简称:城轨)乘客信息系统(PIS,Passenger Information System)运营维护(简称:运维)方式智能化水平低、对人工依赖性强、人工成本高、故障发现慢及处理效率低等问题,设计并实现了城轨PIS智能运维平台。基于特征对比...针对当前城市轨道交通(简称:城轨)乘客信息系统(PIS,Passenger Information System)运营维护(简称:运维)方式智能化水平低、对人工依赖性强、人工成本高、故障发现慢及处理效率低等问题,设计并实现了城轨PIS智能运维平台。基于特征对比、日志分析、决策树等技术,通过主动检测、故障智能检测与诊断、处置决策辅助、远程运维等方式,面向运维人员提供故障告警提示、故障信息展示、故障诊断分析、运维决策建议、远程运维操作等功能,实现了PIS运行过程中故障发现-诊断-处置全流程的快速响应和功能扩展,提高了城轨PIS的运维效率和智能化水平。展开更多
基金the Australian Research Council(ARC)Project No.DP170103341.
文摘The implementation of Intelligent Transport System (ITS) technology is expected to significantly improve road safety and traffic efficiency. One of the key components of ITS is precise vehicle positioning. Positioning with decimetre to sub-metre accuracy is a fundamental capability for self-driving, and other automated applications. Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) is an attractive positioning approach for ITS due to its relatively low-cost and flexibility. However, GNSS PPP is vulnerable to several effects, especially those caused by the challenging urban environments, where the ITS technology is most likely needed. To meet the high integrity requirements of ITS applications, it is necessary to carefully analyse potential faults and failures of PPP and to study relevant integrity monitoring methods. In this paper an overview of vulnerabilities of GNSS PPP is presented to identify the faults that need to be monitored when developing PPP integrity monitoring methods. These vulnerabilities are categorised into different groups according to their impact and error sources to assist integrity fault analysis, which is demonstrated with Failure Modes and Effects Analysis (FMEA) and Fault Tree Analysis (FTA) methods. The main vulnerabilities are discussed in detail, along with their causes, characteristics, impact on users, and related mitigation methods. In addition, research on integrity monitoring methods used for accounting for the threats and faults in PPP for ITS applications is briefly reviewed. Both system-level (network-end) and user-level (user-end) integrity monitoring approaches for PPP are briefly discussed, focusing on their development and the challenges in urban scenarios. Some open issues, on which further efforts should focus, are also identified.
文摘针对当前城市轨道交通(简称:城轨)乘客信息系统(PIS,Passenger Information System)运营维护(简称:运维)方式智能化水平低、对人工依赖性强、人工成本高、故障发现慢及处理效率低等问题,设计并实现了城轨PIS智能运维平台。基于特征对比、日志分析、决策树等技术,通过主动检测、故障智能检测与诊断、处置决策辅助、远程运维等方式,面向运维人员提供故障告警提示、故障信息展示、故障诊断分析、运维决策建议、远程运维操作等功能,实现了PIS运行过程中故障发现-诊断-处置全流程的快速响应和功能扩展,提高了城轨PIS的运维效率和智能化水平。
