ZDPS-2卫星可靠性试验评估方法

Method on reliability assessment for ZDPS-2satellite

皮纳卫星具有研制周期短、采用商用货架式器件的特点,无法完整沿用传统大卫星通过底层元器件或部组件搭建系统可靠性模型计算整星可靠性的方法。针对上述问题,提出了基于试验数据的皮纳卫星可靠性评估体系。通过对机理不同的硬件和软件故障分别建模的方法,实现了ZDPS-2卫星的可靠性评估。对卫星的硬件故障数,基于顺序约束模型和贝叶斯参数估计方法进行拟合,并考虑了不同试验环境对卫星工作环境的等效因子。ZDPS-2卫星硬件可靠性水平估计为3月末0.85。对卫星的软件故障采用加入变点的非齐次泊松过程模型拟合,并选择Logistic模型作为测试覆盖率模型。ZDPS-2卫星软件故障拟合结果,平均无故障时间为217h。ZDPS-2卫星试验结果证实,可靠性满足增长试验设计的要求和任务需求。

With the feature of a short development cycle, and the use of commercial shelf devices, pico-satellites cannot follow the traditional reliability assessment for larger satellites which builds the system reliability model with components. The reliability assessment system of pico-satellites based on experimental data is proposed. The reliability assessment of ZDPS-2 satellites is realized by building different hardware and software failure models respectively. The model of hardware failures is based on the ordering constraint model and the Bayesian parameter estimation method, and the equivalent factor of the different experimental environment to the satellite working environment is considered. ZDPS-2 satellite hardware reliability level is estimated as 0.85 at the end of 3 months. The model of software failures is fitted with the non-homogeneous poisson process (NHPP) model with the change point. The logistic model is chosen as the test coverage model. According to ZDPS-2 satellite software failure results, the average time between failures is 217 h. The ZDPS-2 satellite test results confirm that the reliability meets the requirements for the growth test design and mission requirements.