Get transfer function from bode plot

In summary, the bode plot provided in the given link is a combination of two plots, one showing dB vs. w and the other showing angle vs. w. The answer to the question regarding the transfer function described by this bode plot is "3s", indicating that it is a differentiator type with a slope of 20dB/dcd and an intercept at w=3 on the dB vs. w graph, and a constant angle of 90 degrees on the angle vs. w graph. The given diagram can be interpreted to show these characteristics, leading to the conclusion that the transfer function is 3s.
  • #1
dominicfhk
11
0

Homework Statement


What is the transfer function described by this bode plot:
http://img96.imageshack.us/img96/4775/capturegib.jpg [Broken]
*The answer is 3s, but I don't know where it comes from.

Homework Equations


None

The Attempt at a Solution


Correct me if I am wrong. A bode plot is a combination of 2 plots, one is dB vs. w, the other one is angle vs. w. Each linear transfer function can be breakdown into 7 types of component to be represented on a bode plot. The answer to this problem is "3s", suggesting that it is the differentiator type. For differentiator with w=3, its bode plot has a slop of 20dB/dcd and intercept at w=3 (dB vs. w graph), and an angle of constant 90 degree (angle vs. w graph). I don't see any of the characteristics on the given diagram. I can see that the two plot has been combined into one, but how exact do I interpret such diagram and be able to come up with 3s as the transfer function? Thank you so much!
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
Nevermind, I think I got it. Thanks.
 

1. How do I get the transfer function from a bode plot?

The transfer function can be obtained by analyzing the frequency response of a system using the bode plot. The transfer function is simply the ratio of the output response to the input stimulus in the frequency domain.

2. What information do I need to get the transfer function from a bode plot?

In order to obtain the transfer function from a bode plot, you will need the magnitude and phase data of the system's frequency response. This data can be obtained by measuring the output response of the system at different frequencies.

3. Can I use a bode plot to get the transfer function for any system?

Yes, a bode plot can be used to obtain the transfer function for any linear time-invariant system. This includes systems such as electrical circuits, mechanical systems, and control systems.

4. Is there a specific method for getting the transfer function from a bode plot?

Yes, there are several methods for obtaining the transfer function from a bode plot. One common method is to manually calculate the transfer function using the magnitude and phase data. Another method is to use a mathematical model or simulation to fit the bode plot data and obtain the transfer function.

5. Are there any limitations to getting the transfer function from a bode plot?

One limitation of obtaining the transfer function from a bode plot is that it only provides information about the frequency response of a system. It does not take into account the system's time-domain behavior or any non-linearities. Also, if the bode plot data is not accurate or complete, it may result in an incorrect transfer function.

Similar threads

  • Engineering and Comp Sci Homework Help
Replies
9
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
3
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
14
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
3
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
9
Views
2K
  • Engineering and Comp Sci Homework Help
Replies
1
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
3
Views
983
  • Engineering and Comp Sci Homework Help
Replies
4
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
2
Views
1K
  • Engineering and Comp Sci Homework Help
Replies
7
Views
2K
Back
Top