一种航天测控系统可靠性定量化计算方法

航天测控系统具有动态性、复杂性、可维修性、阶段间相关性等显著特征，作为航天器安全在轨运行的重要保障，其可靠性至关重要。针对航天测控系统可靠性精确计算的难点，提出了综合马尔可夫（Markov）模型和全概率思想的复杂、动态系统可靠性定量化计算方法，给出了计算流程。按照系统的动态组成特性，将任务进程划分为多个阶段，阶段内参试状态不变，不同阶段之间参试状态不同。借鉴Markov模型描述阶段内状态转移过程，通过求解Kolmogorov后向方程得到本阶段结束时的状态概率，利用全概率思想实现阶段间状态映射，体现阶段间的依赖性，依次对各阶段求解获取整个任务可靠性，具有求解准确度高、结果可信度高等特点。最后给出算例，通过与蒙特卡洛仿真结果的比对校验Markov方法的准确性。

A reliability analysis method for space TT&C system

Featured with dynamic, system complexity, maintainability and dependency across successive mission phases, space TT&C system ensures the stable and safe operation for any aerospace project, and its reliability is very important. Regarding the characteristic of space TT&C system, a Markov-based reliability analysis method is presented. In this method, TT&C is treated as a multiple phases mission system, with states keep unchanged in the same mission period, while there possibly exist changes across the different periods. According to the time variant dynamic reconfiguration characteristics, process of internal state transfer in each task stage is described using Markov model, through the Kolmogorov backward equation, the state probability of the system at the mission completion time is calculated, and the dependency between two task stages is fully considered with state mapping by probability theory. Consequently, the whole reliability of the system is derived by solving all the mission stages altogether. The method is proved with high precision and reliable. Finally, an example is given to show the validity of the algorithm through comparing with that of Monte Carlo-based method.