The Failure Intensity Estimation of Repairable Systems in Dynamic Working Conditions Considering Past Effects

To overcome the disadvantages of the traditional proportional intensity model which ignores the past effects of working conditions, this paper proposes an improved proportional intensity model which can describe the failure intensity of repairable systems in dynamic working conditions. First, the contacts among time, working conditions, and failure probability are explained from the perspective of cumulative damage. Then, the correlations of failure intensities in different working conditions are established by using the equivalent damage model, which is the interpretation of the equivalent time model from the perspective of damage. After that, the linear assumption is adopted in the proportional intensity model with a Weibull process as a baseline intensity. The equivalent damage model converts the cumulative damage in different working conditions to standard working conditions, which gives the proportional intensity model the ability to consider past effects. Furthermore, a numerical case and a real-world case are illustrated to verify the effectiveness of the method. The results of the cases show that the cumulative damage and current working conditions are the two main factors that can decide the failure intensity of electromechanical systems in dynamic working conditions.