基于DSPN的航天测控系统任务可靠性仿真建模

提出了基于确定与随机Petri网(deterministic and stochastic Petri nets,DSPN)的航天测控系统(tracking,telemetry and command,TTC)任务可靠性定量分析方法,旨在对相关航天测控方案进行可靠性预计.通过对TTC系统任务剖面进行时序弧段划分,考虑实际系统中测控单元阶段依赖、单元故障可修以及各单元参与任务起止时间不同等其他建模方法难以处理的复杂因素,建立了"单元层-系统逻辑层-阶段层"3层相互关联的TTC系统任务可靠性DSPN模型.通过对模型仿真运行,实现了对给定测控方案下TTC系统任务可靠性定量化评估.分析表明:仿真结果随着仿真次数增加逐渐收敛,与Markov解析方法求得的精确值对比误差控制在1%以内.

Mission reliability simulation modeling of space TT&C system based on DSPN

A general methodology for mission reliability modeling and analysis of space TT&C system using DSPN was proposed to evaluate the TT&C scenarios.By dividing the time sequences of TT&C mission profile and taking into consideration of the complex situations which were difficult to be dealt with by other modeling methods such as phase dependency of TT&C units,reparability of the system and different time intervals for various TT&C units,the mission reliability of TT&C system was modeled by "component-system logic-phase " three levels of Petri nets (PN) that could interact with each other.After simulating the DSPN model,the quantitative assessment mission reliability of TT&C system for given TT&C scenario can be obtained.The case study reveals that the simulation results have a good convergence with the increase of simulation numbers,and the errors are controlled with one percent compared with the analytical result of Markov analytic method.