基于多阶段退化建模的列车电空阀退化预测方法

Degradation Prediction Method for Train Electro Pneumatic Valve Based on Multi-phase Degradation Modeling

摘要:

为了提高列车电空制动系统的可靠性，提出了一种考虑多阶段退化趋势动态变化的电空（electro pneumatic，EP）阀电磁线圈退化状态自适应预测方法。首先，利用加速退化试验数据和指数估计形式来推导扩展卡尔曼滤波（EKF）算法的状态方程和观测方程。其次，基于EKF算法对退化数据进行最优估计，减少退化数据不确定性波动对预测的干扰。然后，根据历史数据的EKF最优估计结果建立退化模型，将下一退化阶段的预测值和观测值信息交互结果用于退化模型的更新。最后，采用自适应遗忘因子对EKF优化后的历史数据样本和新观测数据样本进行动态权重调整，通过多阶段退化建模完成退化模型的参数自适应更新。试验验证结果表明：所提出的退化预测方法可以准确有效地实现多阶段连续退化预测；所提出的自适应遗忘因子权重调整策略可以有效提高退化预测的准确性。

关键词:退化预测;多阶段退化建模;扩展卡尔曼滤波;自适应遗忘因子;电空阀电磁线圈

Abstract:

To improve the reliability of train electro-pneumatic brake system， an adaptive degradation condition prediction method for electromagnetic coils of electro pneumatic （EP）valve， considering multi-phase dynamic changes of degradation trend， is proposed. First， the accelerated degradation test data and exponential fitting form are used to derive the state and observation equations of the extended Kalman filter （EKF） algorithm. Second， the EKF algorithm is used to obtain the optimal estimation of degradation data， reducing the interference caused by uncertain volatility of degradation data. Third， the original degradation model is established based on the optimal estimation of historical data， and the interaction between the predictions and observations of the next degradation phase is used to update the degradation model. In the end， adaptive forgetting factors are used to adjust weights of historical data and new observations after EKF optimal estimation， and adaptive updates of degradation model are accomplished through multi-phase degradation modeling. The verification results show that the proposed approach can accurately and effectively achieve multi-phase continuous degradation prediction； the proposed weight adjustment strategy with adaptive forgetting factors can significantly improve the accuracy of degradation prediction.

Key words:degradation prediction;multi-phase degradation modeling;extended Kalman filter;adaptive forgetting factor;electromagnetic coils of electro pneumatic（EP）valve