一体化电液作动器容错结构设计

一体化电液作动器(EHA, Electrical Hydrostatic Actuator)是功率电传(PBW, Power by Wire)飞控操纵系统的一部分,为了保证整个飞控系统的可靠度,必须采用多余度结构配置.飞控系统分别从可靠度、任务成功率、余度和故障管理水平以及性能、重量等角度提出了EHA的设计指标要求,并按照设计指标要求,对EHA各个组成部分的失效率进行了计算.根据计算结果,针对一种可行的EHA容错结构,分别计算了由于EHA故障导致的任务中断率(PMA, Probability of Mission abort)和失控率(PLOC, Probability of Loss of Control).计算结果表明此种结构形式能够满足飞控系统对作动器可靠度的要求.最后根据选用的可靠度模型,设计出具有容错能力的多余度作动系统,并对此容错结构进行了详细阐述. 

Fault tolerant architecture design of EHA

The integrated EHA(electrical hydrostatic actuator) is an important component of the PBW(power by wire) flight control system.Fault tolerant architecture design is necessary to improve the whole reliability of flight control system.Performance parameters were offered by the demand of reliability,mission abort,redundancy,failure management level,performance,weight and size.The failure rate about each EHA's component was calculated.Based on the calculation result,a feasible fault tolerant architecture of EHA was selected.Then the probability of mission abort and loss of control results from the EHA's failure were calculated separately.Calculation results show that the fault tolerant architecture can meet the flight control system's reliability requirement.Detail design about EHA's architecture was given based on the selected EHA's reliability model,and this kind of EHA system's function was described in particular.