A useful life prediction method based on the integration of the stochastic hybrid automata(SHA) model and the frame of the dynamic fault tree(DFT) is proposed. The SHA model can incorporate the orbit environment, work...A useful life prediction method based on the integration of the stochastic hybrid automata(SHA) model and the frame of the dynamic fault tree(DFT) is proposed. The SHA model can incorporate the orbit environment, work modes, system configuration, dynamic probabilities and degeneration of components,as well as spacecraft dynamics and kinematics. By introducing the frame of DFT, the system is classified into several layers, and the problem of state combination explosion is artfully overcome.An improved dynamic reliability model(DRM) based on the Nelson hypothesis is investigated to improve the defect of cumulative failure probability(CFP), which is used to address the failure probability of components in the SHA model. The simulation using the Monte-Carlo method is finally conducted on two satellites, which are deployed with the same multi-gyro subsystem but run on different orbits. The results show that the predicted useful life of the attitude control system(ACS) with consideration of abrupt failure,degradation, and running environment is quite different between the two satellites.展开更多
基于通信的列车运行控制(communication based train control,CBTC)系统采用车地通信方式使得地面设备极其复杂。随着通信技术的快速发展,以车载为核心的列车运行控制(train-centric communication based train control,TcCBTC)系统采...基于通信的列车运行控制(communication based train control,CBTC)系统采用车地通信方式使得地面设备极其复杂。随着通信技术的快速发展,以车载为核心的列车运行控制(train-centric communication based train control,TcCBTC)系统采用车车通信方式减少了控制信息的传递环节,将成为城市轨道交通领域的发展方向。移动授权(movementauthority,MA)是决定列车能否以安全间隔运行的直接因素,因此对MA生成过程进行形式化建模与分析,对避免列车碰撞具有重要意义。根据TcCBTC系统架构分析MA生成流程,确定参与功能实现的子系统,并计算出不确定性参数;通过UPPAAL-SMC建立对应的随机混成自动机网络模型;最后采用统计模型检测方法对模型进行定量分析。分析结果表明:置信度为99.95%的情况下,系统在300 ms内成功计算出MA的概率为0.9974124748,为后续TcCBTC系统开发设计提供理论参考。展开更多
基金supported by the Fundamental Research Funds for the Central Universities(2016083)
文摘A useful life prediction method based on the integration of the stochastic hybrid automata(SHA) model and the frame of the dynamic fault tree(DFT) is proposed. The SHA model can incorporate the orbit environment, work modes, system configuration, dynamic probabilities and degeneration of components,as well as spacecraft dynamics and kinematics. By introducing the frame of DFT, the system is classified into several layers, and the problem of state combination explosion is artfully overcome.An improved dynamic reliability model(DRM) based on the Nelson hypothesis is investigated to improve the defect of cumulative failure probability(CFP), which is used to address the failure probability of components in the SHA model. The simulation using the Monte-Carlo method is finally conducted on two satellites, which are deployed with the same multi-gyro subsystem but run on different orbits. The results show that the predicted useful life of the attitude control system(ACS) with consideration of abrupt failure,degradation, and running environment is quite different between the two satellites.
文摘基于通信的列车运行控制(communication based train control,CBTC)系统采用车地通信方式使得地面设备极其复杂。随着通信技术的快速发展,以车载为核心的列车运行控制(train-centric communication based train control,TcCBTC)系统采用车车通信方式减少了控制信息的传递环节,将成为城市轨道交通领域的发展方向。移动授权(movementauthority,MA)是决定列车能否以安全间隔运行的直接因素,因此对MA生成过程进行形式化建模与分析,对避免列车碰撞具有重要意义。根据TcCBTC系统架构分析MA生成流程,确定参与功能实现的子系统,并计算出不确定性参数;通过UPPAAL-SMC建立对应的随机混成自动机网络模型;最后采用统计模型检测方法对模型进行定量分析。分析结果表明:置信度为99.95%的情况下,系统在300 ms内成功计算出MA的概率为0.9974124748,为后续TcCBTC系统开发设计提供理论参考。
