Analysis of performance-depleting maintenance on degraded control systems

The control systems have been widely implemented in many realistic applications. Maintenance activities play an important role in ensuring that the system works properly when considering the degraded components. Traditional maintenance model cannot be directly applied to degraded control systems due to the dynamic properties and the feed-back mechanism. In this paper, a time-varying model is proposed to capture the features of degraded components and inner control system. The degradation of component takes into account the unit-to-unit variability. The condition-based maintenance is determined by the real-time performance of degraded control system which is evaluated at inspection times. Monte Carlo Simulation method is introduced to estimate the parameters of the maintenance model and long run cost rate is obtained. A case study on the simulated heat remove system of chemical plant is presented to illustrate the correctness and effectiveness of the entire framework.