基于维纳过程的MEMS陀螺仪贮存寿命评估

目的 针对MEMS陀螺仪在步进应力加速试验条件下获取的性能退化数据，提出基于维纳过程的贮存寿命评估方法及其模型准确度检验方法。方法 首先，确定温度为影响MEMS陀螺仪性能退化的主要环境因素，采用步进温度应力加速试验的方式获取其性能退化数据。其次，分析各项性能参数的演变规律，确定标度因数为表征产品性能退化的特征性能参数。最后，采用漂移维纳过程对标度因数退化轨迹进行建模，并外推得到常温条件下的贮存寿命。结果 采用留一法对模型精度进行验证，模型准确度最低为86.44%。可靠度水平为0.95时，常温贮存(25 ℃)条件下的寿命评估结果为50.02 a。结论 基于维纳过程建立的性能退化模型的准确度在85%以上，该模型可应用于指定贮存条件下MEMS陀螺仪的性能退化预测及贮存寿命评估。

Storage Life Evaluation of MEMS Gyroscope Based on Wiener Process

The work aims to propose a storage life evaluation and model accuracy verification method based on the Wiener process according to the performance degradation data of the MEMS gyroscope obtained in the step-stress acceleration test. Firstly, temperature was determined as the main environmental factor affecting the performance degradation of MEMS gyroscopes during storage, and the performance degradation data were obtained by a step-stress acceleration test. Secondly, the evolution law of each performance parameter was analyzed, and the scaling factor was determined as the characteristic performance parameter. Finally, the linear drift Wiener process was used to establish a model for the degradation trajectory of the scaling factor, and the storage life at actual natural condition was evaluated. The model accuracy was validated by the leave-one-out method, and the minimum accuracy of the model was 86.44%. According to the established model, when the reliability level was 0.95, the storage life in the actual natural environment (25 ℃) was 50.02 years. The accuracy of the performance degradation model based on the Wiener process was above 85%, so the model is applicable to the performance degradation prediction and storage life evaluation of MEMS gyroscopes under specified storage conditions.