With some simplifying assumptions, a transfer function relating the pitch angle, heta , to the
elevator deflection angle, delta , has been derived for a light aircraft as follows:
( heta (s))/(delta (s))=(s+0.2)/(s^(3)+0.7s^(2)+0.9s)
Q 2(a)
[7 Marks]
Sketch where the open loop poles and zeros are located on the s-plane, hence discuss how you
would expect the open loop system to respond to a unit step input in elevator deflection angle.
Include discussion of both transient response and steady-state error in your answer.
Q 2(b)
[3 Marks]
If the desired peak time of the system is 3s and the percentage overshoot should be not more
than 20% determine the required closed loop dominant pole locations.
Q 2(c)
[5 Marks]
Given the root locus plot of the system shown in Figure Q2, discuss whether the performance
requirements in part (b) may be achievable with Proportional control. Include in your
discussion details of what further analysis might be required.Q 2(d)
[5 Marks]
Determine the closed loop system transfer function if unity negative feedback is applied to the
open-loop system.
Q 2(d) [5Marks] Determine the closed loop system transfer function if unity negative feedback is applied to the open-loop system.
2.5
2
1.5
0.5
0
-0.5
-1
-1.5
-2
-2.5 -0.4
-0.35
0-
-0.25 -0.2 Figure Q2
-0.15
-0.1
-0.05
0