英文摘要 |
To ensure control system integrity and hence maintain safety, fault monitoring and diagnostic techniques are employed in many engineering areas. In all approaches of fault diagnostic system design, the model-based design method has received great attention. Since modeling error is inevitable which may deteriorate the function of a model-based fault diagnostic system, therefore, robustness of the fault diagnostic system is an important issue such that the diagnostic results should be immune to the disturbance or modeling error, only related to the present faults. Unknown Input decoupling approach is an important method for designing a robust fault diagnostic system. However, the robust fault diagnostic design required that the disturbance distribution matrix should be known in a priori. Patton et al provide a design procedure for the estimation of the disturbance distribution matrix, but this approach can only be used in the system with the output matrix is square and invertible, which means the number of independent sensors should be the same as the number of process states. This restriction obstructs the use and development of the estimation technique. In this paper, we provide a new design procedure to relax this restriction such that the disturbance distribution matrix can be estimated with lesser sensors. Simulation results demonstrate that the developed approach is practicable and effective. |