1) The document presents a new technique for fault detection and isolation that uses neural networks to generate models of normal and faulty system behaviors. A decision tree is then used to evaluate residuals and isolate faults.
2) The technique is demonstrated on a benchmark process for an electro-pneumatic valve actuator. Neural networks are used to generate models of the actuator's normal and 19 possible faulty behaviors.
3) A decision tree structure is proposed to simplify online fault diagnosis by only evaluating the most significant residuals needed at each step to isolate faults. This reduces computational effort compared to evaluating all residuals.