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

Table 4.4: Full Range RMS Values
Flight:
Sim:
AIL 6.05 9.07
P 0.350 0.330
ELE 2.66 3.98
Q 0.193 0.281
RUD 2.36 2.94
R 0.064 0.075
WHL 1.10 1.77
R 0.064 0.075
Beta 0.047 none
The RMS values for the aileron, elevator, and wheel inputs from the simulation are higher in
magnitude than the flight RMS. The likely explanation is that the simulation operators gave larger
inputs to the control system than the flight operators to the flight test. The rudder RMS values
compare more closely between flight and simulation, however simulation is still larger in
magnitude. The RMS comparisons of the pitch and yaw rates have the same trend as their
respective inputs. The values for the roll rate are almost the same, which is not consistent to the
difference in the magnitudes of the aileron inputs.
Figure 4.22 shows the comparison between the flight and simulation roll rate responses. For
additional comparison, Figure 4.23 shows the same comparison in the pitch axis. The results for
the roll axis show a discrepancy in magnitude which could be due to the x-axis moment of inertia
estimated too large or the aileron control power derivative being estimated too small in the
simulation. Additionally, the phase roll-off is steeper at high frequency for the simulation which
suggests there might be a time delay error. The pitch response also shows an anomaly in the
phase slope at high frequency, which could be a time delay error as well.
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