Abstract:To address the problems of long test duration, difficulty in obtaining failure data, and insufficient prediction accuracy under small-sample degradation data for temperature sensors under actual operating conditions, a degradation trajectory modeling and life prediction method based on accelerated aging test and particle swarm optimization-support vector regression(PSO-SVR)is proposed. First, according to the target operating condition of the temperature sensor, a source accelerated aging condition is designed by considering temperature cycling amplitude, cycling frequency, and electrical stress. The temperature measurement deviation is selected as the performance degradation indicator, and accelerated aging degradation data are obtained. Then, to overcome the strong parameter dependence and insufficient stability of conventional SVR in predicting subsequent degradation trends, PSO is introduced to jointly optimize the penalty factor, kernel parameter, and insensitive loss parameter of SVR, thereby establishing a PSO-SVR degradation trajectory prediction model. To evaluate the prediction ability of the model for future degradation trends, the source-condition data are divided into a model calibration interval and a time-ordered holdout test interval according to the aging time sequence, and the proposed model is compared with the conventional SVR model. Finally, based on the degradation trajectory under the source condition and the equivalent time-axis mapping method, the degradation trajectory under the target operating condition is extrapolated and verified using staged measured data from fourth-level and fifth-level maintenance samples. The results show that the coefficient of determination of the PSO-SVR model in the time-ordered holdout test interval reaches 0.9919, which is higher than that of the conventional SVR model. Under the target operating condition, the predicted life of the conventional SVR model is about 11.59 years, while that of the PSO-SVR model is about 14.08 years. Moreover, the extrapolated degradation trajectory obtained by PSO-SVR is more consistent with the distribution of staged measured data. The results indicate that the proposed method can effectively improve the accuracy of degradation trajectory modeling and the reliability of life prediction for temperature sensors under small-sample accelerated aging data, providing a reference for life assessment and service condition evaluation of long-life temperature sensors.