hmwk2 - u i and y i n are used where n is additive white...

University of California, Santa Barbara
Department of Electrical & Computer Engineering
ECE 147c: Digital Control
Spring 2009
Homework 2. Due 5.00pm Tuesday, 5th May, 2009 in the homework boxes on the 3rd floor of Harold Frank
Hall.
Consider the following continuous time system,
H ( s ) =
100
s 2 + 4 s + 100
.
In this problem, you will use discrete time signals to excite this system through a sample and hold and will
use the data collected to identify its frequency response.
1. Perform a discretization of H using c2d using the zoh option, and a sampling period of 0.05 seconds.
Generate a zero mean white random noise signal using randn and use it as an input to the discretized
system using lsim . Take the resulting output over 10000 and 100000 time samples and name them as
y
1
and y
2
respectively. Name the corresponding parts of the input u
1
and u
2
respectively.
2. Consider two cases for both y
1
and y
2
(four cases in total). The first is where u
i
and y
i
( i = 1 , 2) are
used to identify the frequency response. The second is where