# ELE 302 Lecture Notes - Lecture 39: Damping Ratio, Step Response, Pid Controller

## Document Summary

The damping ratio went down from 0. 59 to. 0. 57, to, and the frequency from = 6. 77 rad/seconds to = 6. 44 rad/seconds, when compared with p+rate feedback design from question 1. Course notes winter 2012 based on the 2nd order model we would expect the overshoot and the settling time to be: The actual specs are: po = 10%, and % 0. 88 seconds. The difference is attributed to the effect of the additional pole zero combo that is not exactly cancelled out. The pole at 0. 689 has a residual effect by contributing a bit of extra damping, hence the slightly smaller overshoot than expected from the. The zero at 0. 7 has a residual effect by contributing a bit of rise, hence the slightly slower settling time. The pi + rate controller is a better controller because it not only meets the step response specifications, it also makes the system type = 1.