
Ch11-H6927.tex 20/6/2007 16: 37 Page 293
Stability Augmentation 293
Seconds
012345678 910
q rad/s
2.0
1.5
1.0
0.5
0.0
0.5
Augmented response
Unaugmented response
Figure 11.10 Pitch rate response to a unit elevator step input.
Substituting the control law, equation (11.33), into the open loop longitudinal
equations of motion as described in Section 11.3 enables the closed loop equations
of motion to be derived. Solution of the equations in the usual way gives the response
transfer functions for the augmented aircraft. Solution of the closed loop characteris-
tic equation determines that at K
q
=−0.5 rad/rad/s the longitudinal modes have the
following characteristics: ...