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For each experiment one of device components is supposed working incorrectly what is
exhibited in a value on its output opposite predicted. A consequence of the incorrect
component work is changing of outputs of those components which produce the results
depending on values on the output of a faulty component. These changed results of
component operations are transmitted to appropriate inquiries of a diagnostic system.
At the beginning of each experiment to inputs of components (Invl, Inv2, Inv3, Inv7, Inv8,
Inv9, Invl3, InvI4, Invl5) in a diagnostic complex the vector of values (1,0,1, 0,1,0, 1,0,1)
enters. Then to the diagnostic system the value 0 retrieved from the output of the
component Nor5 that depends on the work of a broken component and differs from
predicted is transferred. It leads to the appearance of an inconsistency in the diagnostic
system and starts the automatic process of testing.
In Fig. 10 the quantity of the stages required to each method for fault localization is shown.
A method stage is a measurement point choosing. The smaller the quantity of method
stages, the faster a fault is localized.
Fig. 10. The quantity of stages required to each method for fault localization
From the obtained results one can see that the method efficiency for different fault
components is various and hardly depends on the device structure.
Let's estimate the method efficiency. The device is consists of 46 components. The output
values of 45 components are unknown (a value on the output of Nor5 is transmitted to the
diagnostic system with input data together). So, the maximal stage quantity necessary for a
fault definition is equal 45. Let's accept 45 stages as 100 %. For each experiment it is
computed on how many percents each of the developed methods is more effective than
exhaustive search of all values. Then define the average value of results. The evaluated
results are represented in table 1.
The method
SEH
SEH
SCAIEH
On how many percents the method is more effective, %
30,79
63,17
68,65
Table 1. Results of experiments
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