A mobile robot using a vision system as the measurement device is shown in Figure DP7.7(a) [36]. The control system is shown in Figure DP7.7(b) where
G(s) = 1 / (s + 1)(0.5s + 1).
and Gc(.f) is selected as a PI controller so that the steady-state error for a step input is equal to zero. We then have

Design the PI controller so that
(a) The percent overshoot for a step input is P.O. ‰¤ 5%;
(b) The settling time (with a 2% criterion) is Ts ‰¤ 6 seconds;
(c) The system velocity error constant Kv > 0.9; and
(d) The peak time, Tp, for a step input is minimized.
Figure DP7.7
(a) A robot and vision system.
(b) Feedback control system.

Motien subsystem Recognition subsystem Computer Object envronmen fa Controller Plant Y(s)