An Intelligent Health Monitoring and Fault Accommodation Approach for Nonlinear Aircraft Operating in Multiple Regimes

"Here Intelligent Automation, Inc. (IAI) proposes a new approach for designing intelligent health monitoring supervisor and fault tolerant controllers for non-linear air vehicles. First, a novel on-line monitoring system performs model validation and faultdiagnosis. The monitor automatically distinguishes between fault occurrence and operating regime switching. It can directly deal with nonlinear fault models, handle unstructured modeling uncertainty and unexpected failures, and is suitable for real-timeoperations. Second, a new reconfiguration supervisor makes decision regarding controller selection and resource management. The supervisor provides a unified framework for fault diagnosis and fault-tolerant controller, which is still lacking according to arecent survey paper. Another new feature is that the effect of fault detection time on system stability has been explicitly taken into account. Third, a controller suite with novel robust controllers to deal with different failure modes in each regime isproposed. The fault tolerant controllers are designed based on recently developed nonlinear adaptive/neural net techniques by the Principal Investigator, Dr. C. Kwan. The controller guarantees closed-loop stability for a general class of nonlinear systems.Moreover, it has an on-line tuning scheme that eliminates off-line training of the neural net, which is extremely important in rapidly varying environment. The proposed method combines several breakthroughs in fault detection and isolation, and robustcontrol techniques in a unified framework. The proposed method can be used for applications such as aircraft, spacecraft, motors, robots, submarines, and nuclear reactors. We expect the method to be widely used in many commercial and military applications."