A cut/tie set method for reliability evaluation of control systems

This paper discusses the problem of reliability evaluation for control systems. The reliability evaluation in a system level provides an important criteria on the overall system operating performance and it can be used for guiding system reconfiguration upon the occurrence of a component failure. However, due to the dynamical and feedback relations among the elements in control systems, a valid reliability evaluation method is difficult to obtain by conventional approaches in reliability engineering. In this paper, an approach is introduced to evaluate the reliability by searching for the equivalent tie sets or cut sets based on the control system performance. When a fault is detected and identified on-line and/or the control objective is changed, the reliability can be easily re-evaluated by updating the cut sets or tie sets.