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

e = δ − f
[4.2]
e δ f f
= − = 1 −
δ δ δ δ
[4.3]
Figure 4.7: Feedback Block Diagram
Figure 4.8: Error Channel Verification
Using the MATLAB version of CIFER ® ’s utility 8 for crossover characteristics, the feedback
response to error in the lateral axis was analyzed. A time delay of 0.0402 was incorporated into
the CIFER crossover analysis because the time delay was not present in the simulated flight
recordings. This modification is not entirely correct because it puts the time delay over the entire
system as opposed to just within the forward loop where it actually occurs. It is, however, a
reasonable approximation. Table 4.1 shows the results from CIFER ® as compared in Unix and
from Matlab to those printed in the training course manual. There was no discrepancy between
the two difference CIFER ® calculations.
Table 4.1: Roll Gain/Phase Margin Results
CIFER, From Unix CIFER, From MATLAB CONDUIT % Difference
Margin Frequency Margin Frequency Margin Frequency Margin Frequency
Gain (1) -10.67 0.41 -10.67 0.41 -10.3 0.48 3.57 13.18
Gain (2) 22.84 13.54 22.84 13.54 24.42 14.85 6.47 8.82
Phase 56.35 2.19 56.35 2.19 57.2 2.13 1.49 2.64
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