Fault detection in dynamic systems

In the control of industrial systems, it is rare that a control system functions continuously without shoutdown throughout the scheduled life cycle of the plant and controller hardware. Owing to ware of mechanical and electrical components, both actuoators, sensor and internal components can fail in more or less critical ways. For safety critical processes, it is of paramount importance to detect when faults are likely to happen and then to identify these faults as fast as possible once they have occurred.
To meet such industrial needs, a number of schemes for fault detection and isolation (FDI) have been set up. Much of the research has dealt with the design of filters which monitor a process and generate alarms when faults have occurred. In most cases, the filters are model based devices which act indepently of the computer implemented digital controller.
In this project, the focus is on both analysis and design of fault detectors as well as the task of combining control algorithm and FDI filters in a single module.
In the area of analysis and design of fault detectors, both observer based detectors as well as more general filters are applied. The work done in this area has primary been focus on the possibility to apply systematic standard methods from robust and optimal control for the analysis and design of fault detectors.
The work done until now in the area of combining fault detector and controller has just been started. A general setup for the design of a combined fault detector and controllers has been formulated using standard methods from robust control. It has been shown by examples, that it is possible to obtain a very large reduction the dynamic order of the control module compared to the case when separate fault detector and controller are applied.