Lecture 15

Question 1

What is the Fourier transform used for

Answer 1

Help model the frequency response of a system

Question 2

What’s the difference between Laplace and Fourier transform and what does this mean

Answer 2

S has been replaced with jw so to get frequency response replace s with jw

Question 3

What’s the difference between the bode diagram approximation and the actual value

Answer 3

The actual values are curved and vary particularly around the natural frequency

Question 4

How do we plot gain for a complex transfer function

Answer 4

Can plot the gain asymptotes for each term separately then add them together to get the gain for the system

Question 5

How do you add multiple asymptotes together

Answer 5

Evaluate them at any turning points and the furthest left hand and right hand of the diagram

Question 6

What are the solutions steps for using bode diagrams

Answer 6

Identify standard terms from the table
Choose suitable scale for the graph axes
Draw asymptotes for each term
Add together value of each asymptotes

Question 7

What do bode diagrams illustrate

Answer 7

The dynamics of a systems reponse

Question 8

How can bode diagrams be constructed

Answer 8

Using experimental analysis, from analytical transfer function, using asymptotic approximations, exact graphical solution