中国列车控制系统(Chinese train control system,CTCS)作为一种安全苛求系统,使用前需要经过严格的安全分析和测试。对我国铁路客运干线主要采用的CTCS-3级列控系统而言,由于传统的安全分析方法主要关注单一场景,因而对其复合场景的安...中国列车控制系统(Chinese train control system,CTCS)作为一种安全苛求系统,使用前需要经过严格的安全分析和测试。对我国铁路客运干线主要采用的CTCS-3级列控系统而言,由于传统的安全分析方法主要关注单一场景,因而对其复合场景的安全性分析存在欠缺。此外,CTCS-3列控系统对控制时序有严格要求,现有安全分析方法难以有效解决该问题。为解决上述问题,采用基于系统理论的过程分析方法,以便更全面、更准确地分析CTCS-3级列控系统的安全性。首先,在分析CTCS-3级列控系统典型运营场景的基础上,提取由列控系统直接控车的运营场景,并建立分层控制结构模型;其次,结合时序逻辑辨识运营场景的不恰当控制行为,并将各场景中互不冲突的不恰当控制行为组合成复合场景;最后,对复合场景进行分析,辨识导致不恰当控制行为的控制缺陷。仿真结果表明:系统理论的过程分析方法可以实现对CTCS-3级列控系统复合场景功能的安全性分析。展开更多
现有高级辅助驾驶系统(Advanced Driver Assistance Systems,ADAS)功能不断增多且系统复杂性不断提高,不可避免带来了预期功能安全(Safety of the Intended Functionality,SOTIF)问题。触发条件的识别与生成是预期功能安全活动中重要的...现有高级辅助驾驶系统(Advanced Driver Assistance Systems,ADAS)功能不断增多且系统复杂性不断提高,不可避免带来了预期功能安全(Safety of the Intended Functionality,SOTIF)问题。触发条件的识别与生成是预期功能安全活动中重要的一环,然而现有对触发条件识别仅借助系统过程理论分析方法(System Theoretic Process Analysis,STPA)进行分析,未充分考虑系统功能状态转换中存在的问题。本文以知识驱动的方式构建触发条件识别机制,将STPA及有限状态机(Finite State Machine,FSM)理论融合构建拓展型系统控制结构,针对拓展型控制架构及功能状态转换进行安全分析,根据系统存在的功能局限及人为误用,完成触发条件的识别、生成、规范化描述、分类及标签化。最后将本文提出的触发条件生成机制应用于集成式巡航辅助系统(Integrated Cruise Assistance,ICA),得到了该系统的触发条件及其分类,并将本文所提出的生成机制与现有相关触发条件生成方法进行对比分析,证明了本机制的实用性、可行性及有效性。展开更多
With the degeneration of environment and acceleration of urbanization,human environment has attracted great attention worldwide.This paper sets up the Human Settlements Environment Index(HEI) model and evaluates the n...With the degeneration of environment and acceleration of urbanization,human environment has attracted great attention worldwide.This paper sets up the Human Settlements Environment Index(HEI) model and evaluates the natural environment suitability for Human Settlements in China based on GIS technology.The results show that the HEI of China decreases from southeast to northwest in general,HEI is significantly correlated with population density at grid size and the correlation coefficient(r) between them reaches 0.93,which indicates that natural environment suitability for Human Settlements has a significant influence on population distribution.Most people in China mainly concentrate in areas with high natural environment suitability.The total suitable area is 430.47×104 km2,which accounts for nearly 45% of the total land area in China,while the proportion of people living in the area reaches 96.56%.With a population density of 18 people per square kilometer,the critical area is the transitional region for people to live in China.The critical area covers 225.11×104 km2 with a population of 41.12 million.The non-suitable area covers 304.42×104 km2 with a population of only 2.49 million.展开更多
文摘中国列车控制系统(Chinese train control system,CTCS)作为一种安全苛求系统,使用前需要经过严格的安全分析和测试。对我国铁路客运干线主要采用的CTCS-3级列控系统而言,由于传统的安全分析方法主要关注单一场景,因而对其复合场景的安全性分析存在欠缺。此外,CTCS-3列控系统对控制时序有严格要求,现有安全分析方法难以有效解决该问题。为解决上述问题,采用基于系统理论的过程分析方法,以便更全面、更准确地分析CTCS-3级列控系统的安全性。首先,在分析CTCS-3级列控系统典型运营场景的基础上,提取由列控系统直接控车的运营场景,并建立分层控制结构模型;其次,结合时序逻辑辨识运营场景的不恰当控制行为,并将各场景中互不冲突的不恰当控制行为组合成复合场景;最后,对复合场景进行分析,辨识导致不恰当控制行为的控制缺陷。仿真结果表明:系统理论的过程分析方法可以实现对CTCS-3级列控系统复合场景功能的安全性分析。
文摘现有高级辅助驾驶系统(Advanced Driver Assistance Systems,ADAS)功能不断增多且系统复杂性不断提高,不可避免带来了预期功能安全(Safety of the Intended Functionality,SOTIF)问题。触发条件的识别与生成是预期功能安全活动中重要的一环,然而现有对触发条件识别仅借助系统过程理论分析方法(System Theoretic Process Analysis,STPA)进行分析,未充分考虑系统功能状态转换中存在的问题。本文以知识驱动的方式构建触发条件识别机制,将STPA及有限状态机(Finite State Machine,FSM)理论融合构建拓展型系统控制结构,针对拓展型控制架构及功能状态转换进行安全分析,根据系统存在的功能局限及人为误用,完成触发条件的识别、生成、规范化描述、分类及标签化。最后将本文提出的触发条件生成机制应用于集成式巡航辅助系统(Integrated Cruise Assistance,ICA),得到了该系统的触发条件及其分类,并将本文所提出的生成机制与现有相关触发条件生成方法进行对比分析,证明了本机制的实用性、可行性及有效性。
基金National Natural Science Foundation of China,No.40771204No.40801223National Key Technology R&D Program,No.2006BAC18B01
文摘With the degeneration of environment and acceleration of urbanization,human environment has attracted great attention worldwide.This paper sets up the Human Settlements Environment Index(HEI) model and evaluates the natural environment suitability for Human Settlements in China based on GIS technology.The results show that the HEI of China decreases from southeast to northwest in general,HEI is significantly correlated with population density at grid size and the correlation coefficient(r) between them reaches 0.93,which indicates that natural environment suitability for Human Settlements has a significant influence on population distribution.Most people in China mainly concentrate in areas with high natural environment suitability.The total suitable area is 430.47×104 km2,which accounts for nearly 45% of the total land area in China,while the proportion of people living in the area reaches 96.56%.With a population density of 18 people per square kilometer,the critical area is the transitional region for people to live in China.The critical area covers 225.11×104 km2 with a population of 41.12 million.The non-suitable area covers 304.42×104 km2 with a population of only 2.49 million.
