Managing Performance Degradation in Fault Tolerant Control Systems

A fault tolerant control system design technique has been proposed and analyzed for managing performance degradation in the presence of multiplefaults in actuators. The method is based on a control structure with model referencereconfigurable control design in an inner loop and command input adjustment in an outer loop. The reduced dynamic performance requirements in the presence ofdifferent actuator faults are accounted for through different performance reduced (degraded)reference models. The degraded steady-state performance are governed bythe reduced levels of command inputs. The reconfigurable controller is designed on-line and automatically and the command input is also re-adjusted in real-time to prevent potential actuator saturation. The proposed method has been evaluated and analyzied using an aircraft example.