A system that controls the mean arterial pressure during anesthesia has been designed and tested [12]. The level of arterial pressure is postulated to be a proxy for depth of anesthesia during surgery. A block diagram of the system is shown in Figure AP4.5, where the impact of surgery is represented by the disturbance Td(s).
(a) Determine the steady-state error due to a disturbance Td(s) = 1/s (let R(s) = 0).
(b) Determine the steady-state error for a ramp input r(t) = t, t > 0 (let Td(s) = 0).
(c) Select a suitable value of K less than or equal to 10, and plot the response y(t) for a unit step disturbance input (assume r(t) = 0).
Figure AP4.5
Blood pressure control.

Surgical disturbanee Tats Patient Ris) Desired Valve setting Yis) Vapor s 2)2Actual blood pressurc pressure