Fa2004 16.33311-4 Poles near origin dominate response s=-01056+0.281li →n=0.3,=0.35 Rules of thumb for 2nd order response 10-90% rise time t=1+1.1+1.42 Settling time(5%) Time to peak amplitude tp Peak overshoot Figure 5: Time response for the altitude controller Predictions: tr=5.2sec, ts=284sec, tp=11.2sec, Mp=0. 3 Now with h feedback, things are a little bit better, but not much Real design is complicated by the location of the zeros Any actuator lag is going to hinder the performance also Typically must tweak inner loop design for altitude controller to work wellFall 2004 16.333 11–4 • Poles near origin dominate response s = −0.1056 ± 0.2811i ⇒ ωn = 0.3, ζ = 0.35 – Rules of thumb for 2nd order response: 1 + 1.1ζ + 1.4ζ2 10­90% rise time tr = ωn 3 Settling time (5%) ts = ζωn Time to peak amplitude tp = � π ωn 1 − ζ2 Peak overshoot Mp = e−ζωntp 0 10 20 30 40 50 60 −0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4 Altitude controller height time Figure 5: Time response for the altitude controller. • Predictions: tr = 5.2sec, ts = 28.4sec, tp = 11.2sec, Mp = 0.3 • Now with h feedback, things are a little bit better, but not much. – Real design is complicated by the location of the zeros – Any actuator lag is going to hinder the performance also. ⇒ Typically must tweak inner loop design for altitude controller to work well