大型卫星地面站故障诊断的增强分层有向图方法

为了解决传统分层有向图模型在卫星地面站故障诊断面临的问题，提出了基于增强分层有向图模型的故障诊断方法。在建模过程中，考虑到卫星地面站故障征兆多、建模复杂，依据各设备工作状态的故障传播方式合并同类节点，以减小模型规模；同时，在模型中加入节点有效性使能函数，克服传统分层有向图模型中设备主备切换导致系统结构发生改变时需要重新建模的问题。在故障诊断推理过程中，采用反向回溯和正向推理相结合的方法减小故障源搜索空间，并基于各节点被搜索次数给出故障概率，提高诊断效率。以北斗卫星无线电测定业务地面站为例对单故障和多故障报警场景下的故障诊断方法进行了验证。结果表明，基于增强分层有向图模型的故障诊断方法可以提高故障诊断的准确率和全面性。

Enhanced hierarchy directed graph method for fault diagnosis of large-scale satellite ground station

To solve shortcomings of traditional hierarchy directed graph method when applied to satellite ground station fault diagnosis, the EHDG (enhanced hierarchy directed graph) fault diagnosis method was proposed. In process of modeling, considering large number of fault symptoms and complex modeling, nodes of the same kind were consolidated according to the fault propagation paths of devices working status to reduce the scale of the model. Furthermore, the node effectiveness enabling function was introduced into the model to overcome the problem of remodeling in the traditional hierarchy directed graph model when the system structure was changed caused by the active/standby switching of device. In process of fault diagnosis reasoning, the search space of fault source was reduced by the combination of backtracking and forward reasoning method. The fault probability was calculated with the number of search hits of the nodes in order to enhance the efficiency. Fault diagnosis method in single fault and multiple faults scenarios of BeiDou radio determination satellite service ground station system was verified, and the results demonstrate that the EHDG method improves the accuracy and comprehensiveness in fault diagnosis.