Hierarchical fault tolerant control using component based models

This paper presents a hierarchical Fault Tolerant Control architecture using a component-based model of a complex system. In this model, components (actuators, sensors, linkages, etc.) are modeled individually with the interactions between components represented by an interconnection structure. The Fault Tolerant Control strategy has three levels to the hierarchy. The highest level encompases Fault Detection and Identification (FDI) to identify failure conditions. The middle level then redistributes the available control authority among healthy subsystems, calculates optimal control setpoints to maintain stability of the system, and adjusts local controller gains to boost system performance. The lowest level consists of the local subsystems and corresponding controllers. As an example, this approach is applied to a multi-tank process in the presence of a stuck actuator.