Large antenna, as shown in Figure CP7.6(a), is used to receive satellite signals and must accurately track the satellite as it moves across the sky. The control system uses an armature-controlled motor and a controller to be selected, as shown in Figure CP7.6(b). The system specifications require a steady-state error for a ramp input r(t) = Bt, less than or equal to 0.01B, where B is a constant. We also seek a percent overshoot to a step input of P.O. ‰¤ 5% with a settling time (with a 2% criterion) of Ts ‰¤ 2 seconds.
(a) Using root locus methods, create an m-file to assist in designing the controller.
(b) Plot the resulting unit step response and compute the percent overshoot and the settling time and label the plot accordingly.
(c) Determine the effect of the disturbance Td(s) = Q/s (where Q is a constant) on the output Y(s).
Figure CP7.6
Antenna position control.

Motor and antenna 10 Ta) Controller YIS Position RIS G(s)