Stochastic Methodology for Prognostics under Continuously Varying Environmental Profiles

We present a stochastic modeling framework for sensor-based degradation signals that predicts, in real time, the residual lifetime of individual components subjected to a time-varying environment. We investigate the future environmental profile that is deterministic and evolves continuously. Unique to our model is the union of historical data with real-time sensor-based data to update the degradation model and the residual life distribution (RLD) of the component within a Bayesian framework. The performance of our model is evaluated on the basis of degradation signals from both numerical experiments and a case study using real bearing data. The results show that our approach accurately estimates the RLD by incorporating the environmental effects and utilizing the real-time observations. (c) 2012 Wiley Periodicals, Inc.