# HW 7 Prob 1 Comments

From MurrayWiki

Remember that when you use the Ziegler-Nichols method, you need to plot the unit step response for the plant. You must draw the steepest tangent line to the step response until it crosses the two axes. You can then approximate the values for "a" and "tao" by visual or numerical approximation. Knowing these values will then allow you to determine the values of othe parameters found on Table 10.1 on pg. 301 of AM08. You should also plot the step response of the closed-loop system and determine the phase and gain margins. As usual for all HW questions, give a title to your plots, label axes, and turn in code along with your plots. --Soto 14:20, 25 November 2007 (PST)