 Find the transfer function Y(s)/R(s) for the following block diagram.
 Find the transfer function Y(s)/R(s) for the following block diagram.
 Consider the block diagram illustrated in the following figure.
 a = 1, b = 1;
 a = 2, b = 1;
 a = 1, b = 2; and,
 a = 1, b = 1.
 Consider the block diagram in the following figure.
 a = 1, b = 1;
 a = 1, b = 1;
 a = 1, b = 1; and,
 a = 1, b = 1.
 For the transfer function in problem 4 let a=1 and b=3. Compute the partial fraction expansion by hand and plot the three terms in the response (the term due to A/s, the term due to B/(sa) and the term due to C/(sb)) and verify that the response from the step() command is the sum of these three terms.
Homework 10, due April 20, 2005.

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Homework 10, due April 20, 2005.
Last edited by goodwine on Thu Jun 15, 2006 4:17 pm, edited 4 times in total.

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For problem 4, parts b & c, I am finding that the denominators of several of the y(t) terms are zero, which makes little sense to me. If a and b are the same then isn't 1/(a^2  ab) undefined? I don't know if I'm missing the point to this problem or what, but if someone could point me in the right direction it would be much appreciated.

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If a=b you can't use the partial fractions that I did in class since there was a division by (ab) or (ba) at some point in it.kp316 wrote:For problem 4, parts b & c, I am finding that the denominators of several of the y(t) terms are zero, which makes little sense to me. If a and b are the same then isn't 1/(a^2  ab) undefined? I don't know if I'm missing the point to this problem or what, but if someone could point me in the right direction it would be much appreciated.
If a=b you need to partial fraction
A/s + (Bs+C)/(s+a)^2 = 1/(s(s+a)^2).
You can either do it twice with the numbers substituted, or try it with just an a or b so you only have to do it once, but I'm not sure how bad the algebra gets in the latter case.
Bill Goodwine, 376 Fitzpatrick
step function
I went to do the step function analysis on Matlab and it said that there is not function called step.m???

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Re: step function
If you are using your own student version, perhaps the controls package isn't part of it.NDChevy07 wrote:I went to do the step function analysis on Matlab and it said that there is not function called step.m???
Bill Goodwine, 376 Fitzpatrick