Service diagnosis utilizing the dependencies between the system structure and the operating points

The paper presents a new approach to the generation of test signals used in service diagnosis. The tests make it possible to isolate faults, which are generally not isolable, but can be distinguished if the system is brought into specific operating points. The basis for the test signal selection is a graph that represents the couplings among the external and internal signals of the system and the faults. This graph is used to identify edges that disappear under certain operating conditions and prevent a fault from changing the system behavior in this operating point. The test generation method is illustrated by a process engineering example.