Importance measures for control systems with degrading components

This paper addresses the issue of importance analysis for control systems. The control system is a complex system consisting of multiple components, where its components interact with each other in complicated mechanisms. Different form traditional systems, a feedback channel exists in the control system which dominates the system behavior in a complicated way. For such a complex system, importance measures are desired to provide insights of the dominated components and simplify performance analysis of the system. In this paper, we perform importance analysis on several typical components of the control system, namely, the controller, actuator and sensor. These components are subject to deterioration during system operation. We firstly describe the system behavior by analyzing the forward channel and feedback channel, followed by the reliability model and importance analysis. Monte Carlo simulation is adopted to compute system reliability and component importance, owing to the fact that the control system exhibits complex behaviors and no analytical solution can be achieved. Finally, a numerical example is presented to illustrate the reliability model and importance metrics.