中文摘要：

在轨空间机构在服役期间，其性能参数往往会因为耗损性机理（如磨损）发生退化，是具有多性能参数输出的多状态系统。因此，基于“两态性”假设的传统可靠性分析方法并不能准确的分析在轨空间机构的多状态可靠性。针对此问题，提出了性能退化和通用生成函数（Universal generating function，UGF）相结合的系统多状态可靠性分析方法。建立了性能参数分布矢量模型，在此基础上利用UGF建立了多性能参数退化下的在轨空间机构系统多状态可靠性模型。分别给出了已知退化机理模型和未知退化机理模型两种情况下的状态概率计算方法，并提出了多性能参数退化下的系统可靠度分析方法。结合双轴驱动机构系统的实例分析，验证了所提方法的有效性，具有工程应用的指导意义。

英文摘要：

Space mechanism in orbit is a system with the output of multiple performance parameters which tend to degrade because of degradation mechanism. So space mechanism in orbit is a multi-state system with multiple rates of performance. Traditional reliability analysis methods based on the binary state assumption cannot accurately analyse the reliability of space mechanism in orbit. For the purpose of accurate analysis of system reliability, a multi-state reliability analysis method based on the performance degradation and universal generating function （UGF） is proposed. The performance distribution model was built and the arithmetic model is embedded into the structure/property function and performance rates combination model by UGF. On this basis, a multi-state reliability model of the system is established. The state probability analysis method of the known degradation mechanism model and the unknown degradation mechanism model is given respectively, and the multi-state system reliability analysis method under multi-performance parameter degradation is proposed. This method is effective and feasible validated by conducting an example on a two-axes-position mechanism of a satellite antenna.