Dynamic system reliability modeling using extended hybrid Petri nets

Traditional system reliability model has almost neglected the coupling between different states (normal, failures, etc) and the continuous variation process of performance. This paper presents a method of system reliability modeling based on hybrid Petri nets (HPN), which combines the discrete state and continuous performance together during the system to describe the coupling relationship. Firstly, the system normal running mode and fault mode were established using HPN to describe the logical relationship between the discrete states; Secondly, on account of each discrete state, the corresponding continuous performance models were established and uncertain external influencing factors were introduced. Besides, The degradation process can be described by transitions among discrete states and physical modeling by (physical) equations that govern the degradation process. And the time-dependent transition rates associated with model parameters were introduced to describe the switch as a bridge between discrete states and continuous performance characteristics; Finally, the running mechanism were considered and a hydraulic case was modeled by this method.