基于定期不完美主动切换策略的温备系统运行优化模型

Operation strategy optimization for warm standby system considering imperfect and periodic active switching

对于备份系统的运行,备份单元通常在主用单元发生故障后切换到运行状态,这种切换策略称为普通切换策略.然而,卫星上的一些关键子系统在轨运行时采用了一种新的定期切换策略,针对这两种策略的优劣比较问题,本文基于定期主动切换策略提出了温备份系统运行策略优化模型.首先引入了单元的虚拟寿命理论,再在单元寿命服从任意分布类型下,考虑切换装置可能故障,推导出了温备份系统的可靠度和平均失效时间的解析表达式,然后通过最大化温备系统的平均失效时间来获得优化的定期切换间隔.最后,以威布尔分布下卫星上的陀螺仪温备份子系统为例,说明了模型的适用性和有效性,并对相关参数进行了敏感性分析.

Concerning the operation of standby systems in most ground systems,the standby units usually switch to the operating state after the active units fail,this strategy is referred to as the common switching strategy.However,a periodic switching strategy differing from this common strategy is employed for some critical subsystems of satellites on orbit in engineering.For this problem,this paper proposes an operation strategy optimization model for warm standby systems considering periodic active switching.The model comprehensively considers periodic switching and imperfect switching,and based on the virtual age theory,derives the reliability function and mean time to failure(MTTF)of the two-unit warm standby subsystem,which can be applied to units or systems with arbitrary time-to-failure distributions.Then,the optimal periodic switching interval is determined by maximizing the MTTF of the warm standby system.Finally,a numerical example of the gyroscope warm standby system under the Weibull distribution is presented to show the application of the model,and a sensitivity analysis is carried out to identify the useful conclusions.