Issues in fault detectability for dynamic systems

Research on fault detection has witnessed an increasing interest. However, little attention has been dedicated to certification of such systems. There is a significant need to develop means and methodologies that allow an effective verification of fault detection system capabilities. Certification processes involve specification of system requirements followed by testing of the system against them. Within this process we focus our attention on validation of detection requirements. An accurate analysis of detection feasibility is an important step toward specification of meaningful requirements. The paper presents a detectability criterion in the frequency domain for faults in linear systems. The major advantage of this criterion is that it is independent of the fault detection approach adopted. An example of detectability analysis on an inverted pendulum system is provided