测控任务可靠性的近似零方差重要抽样仿真

评价航天测控方案中的测控任务可靠性需要高效的方法,解析法和直接仿真都不能满足该要求.在介绍测控任务模型及其可靠性直接仿真法的基础上,基于不交化最小割集设计了实现近似零方差重要抽样的方法,并给出不交化最小割集的获取算法.通过案例分析,得出不交化最小割集最大获取数量越大,仿真收敛性越好,但相应地耗时也越多的结论.因此,实际应用中,需要在不交化最小割集获取数量与仿真时间二者间进行权衡.

Reliability Simulation of TT&C Mission Using Approximate Zero Variance Importance Sampling

Neither analytical methods nor crude simulation meets requirements for evaluation of the reliability of TT&C missions in a TT&C plan and a more efficient method has to be developed.Following introduction of TT&C mission models and reliability evaluation method of crude simulation,an approximate zero variance sampling method is designed based on non-intersection minimal cut sets and an algorithm used to obtain non-intersection minimal cut sets is given.Case analysis shows higher the maximum number of non-intersection minimum cut sets is,better is the convergence of simulation,but more time is consumed.Therefore,a tradeoff has to be made between the number of non-intersection minimum cut sets and simulation time.