基于非线性退化模型的加速度计寿命评估

针对传统性能退化模型难以对退化轨迹为非线性的设备进行有效寿命评估的问题,首先,建立了一种基于扩散过程的非线性模型,并将推导其失效阈值首达时间分布的问题转化为推导标准布朗运动失效阈值首达时间分布的问题,得到了首达时间意义下的近似寿命分布;然后,提出了该模型未知参数的极大似然函数估计方法;最后,使用此模型评估分析了一组加速度计的寿命,并与传统退化模型进行比对分析。实验结果证明了模型的评估结果更为准确有效。

Lifetime Evaluation of Accelerometer Based on Nonlinear Degradation Model

A nonlinear model based on the diffusion process is established in light of the difficulty of evaluating the life of equipment with traditional performance degradation models. Standard Brownian motion is introduced for the deduction of the first hitting time distribution of crossing fail boundary. Thus, the approximate life time distribution in terms of the first hitting time is obtained. Then, the maximum likelihood estimation method is proposed to estimate the unknown parameters in this model. Finally, the model is used to evaluate and analyze the lifetime and reliability of a set of accelerometers. Comparison with traditional methods proves that the proposed model is more practicable and accessible.