在复杂系统可用度分析中，采用深度和广度遍历算法将复杂动态故障树分解为独立子树，推导和证明了独立子树等效时变可用度参数模型，建立了各独立子树同构的马尔可夫状态转移链。通过求解降维微分方程获得故障子树的时变可用度参数，采用由下至上的递归处理算法快速实现复杂系统的可用性定量分析，既解决了复杂系统可用度计算的“组合爆炸”问题，又通过考虑时变参数保证了可用度解算的精度。实例分析表明，采用独立子树等效时变可用度分析方法在有效的分解下，其误差可以很小。

提出面向对象的计算机辅助故障模式影响分析（CFMEA）方法，建立了控制系统仿真模板，将其数据、操作和性能封装成一个对象，对象间通过属性进行因果推理，实现FMEA向故障树（FTA）的自动转换。引入控制系统性能可靠性概念，建立控制系统性能和功能综台可靠性模型，开发相应的解算方法。实例分析证明了基于仿真模板的控制系统可靠性分析的有效性，综合了功能和性能可靠性分析的优点。

This paper establishes the accelerated life testing model, viz. the hybrid Weibull distribution model under multi-stresses (pressure, velocity and temperature) for typical mechanical product-aerial hydraulic pump. Direct toward the optimization difficulties with multi-parameters in Maximum Likelihood Estimation (MLE), this paper presents an Improved Float Genetic Algorithm (IFGA), which adopts the fuzzy algorithm in the float genetic algorithm to approach the global optimum solution. Application denotes that IFGA not only can obtain the global optimum solution but also can shorten the calculation time greatly.

Hydraulic actuation system is typical displacement control system whose performance is subjected to random inputs from noise, random disturbance from pump vibration or parameter changes. Through importing the integral item of residual error in different rank, this paper establishes the Proportion-Integral Observer (PIO) that can eliminate the influence of random input, parameter excursion and inherent disturbance and realize the fault diagnosis robustly. In order to reach the high fault coverage and low false alarm, this paper provides twin-threshold and corresponding fault decision-making strategy that not only considers the inherent noise existed in the system but also can manifest the fault information effectively. Application and simulation of hydraulic actuator system indicates that the adaptive fault diagnosis can detect the failure in high precision at the stochastic condition.