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

4.3 UH-60 Simulation
The first in-depth validation of the CIFER ® -MATLAB interface was based on UH-60 simulation
data provided in the Combined-CIFER-CONDUIT-RIPTIDE Training course 6 . This course was
designed to give engineers a brief introduction to the three programs developed and distributed by
the Flight Controls Group, of which CIFER ® is one. The second program is CONDUIT ®7 , which
is designed to optimize a control system around a parametric model for a system. The third
program is RIPTIDE ®8 , which is a simulation program that will allow users to fly systems
modeled in CONDUIT ® . Together, the programs constitute a very powerful control systems
design suite.
The course data was examined for crossover and bandwidth characteristics using CIFER ®
utilities. The reference values for these properties were already provided from CONDUIT ®
analysis and were used as a check to ensure the correctness of the CIFER ® results. The course
manual provided closed-loop data necessary for bandwidth analysis. In order to investigate
crossover characteristics it was necessary to generate additional simulated flight recordings, in
RIPTIDE ® , of the feedback and error channels. Only the roll channel was examined for this
analysis.
As a first step in the analysis, frequency response arithmetic (CIFER ® utility 9) was used to
confirm the consistency of data channels used for error and feedback. Equations 4.2 and 4.3 show
the relation of the error signal to the input and feedback signals for a conventional feedback setup
as depicted in Figure 4.7. Figure 4.8 shows the plot of the error response to stick input compared
to the response solved with the MATLAB version of CIFER ® utility 9 using Equation 4.3. The
results overlay precisely, which was expected given that the data comes from a simulation.
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