CIFER®-MATLAB Interfaces: Development and ... - Cal Poly

place. To date no major discrepancy has been observed in the overall results generated by
CIFER ® .
Several tests were conducted to locate a more exact cause of the error. The first method was to
create a case in MATLAB using the interface functions and then create a second identical case
(except in name) the traditional way from within CIFER ® . From here the frequency response
results could be extracted and compared. This was how the error was initially discovered.
Comparisons of the errors in magnitude and phase were plotted as shown in Figure 3.2, which
revealed that slightly larger errors occurred at high or low frequency, regions that tend to exhibit
low coherence. The trend was not completely true in all cases, but most plots tended to exhibit
that behavior. Several different cases including the XV-15 data, Shadow 200 data (Figure 3.2),
UH-60 simulation data, and an example mass-spring-damper system were examined in this
manner, with the results generally being the same. Figure 3.2 is a plot of the percent error; as
such, it can be seen that these errors are small in magnitude.
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