Lead-lag system and model with Simulink

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Discussion Overview

The discussion revolves around constructing a lead-lag system model using Simulink, specifically addressing challenges related to incorporating multiple step inputs into a transfer function. Participants explore various methods to achieve this within the context of a homework assignment.

Discussion Character

  • Homework-related, Technical explanation, Debate/contested

Main Points Raised

  • One participant expresses difficulty in incorporating three step inputs into a transfer function, attempting to use both multiple step blocks and a vector input.
  • Another participant suggests using a summing block along with three separate step blocks as a potential solution.
  • A different participant points out that the transfer function presented appears to be a unity gain element rather than a lead-lag block, questioning the classification.
  • Some participants note a possible misunderstanding regarding the definition of a lead-lag system and suggest reviewing the problem statement for clarification.
  • There is mention of time constants in transfer functions, indicating their importance in the context of the problem.
  • One participant acknowledges a potential typo in the transfer function provided by the original poster.

Areas of Agreement / Disagreement

Participants exhibit a mix of agreement and disagreement, particularly regarding the classification of the transfer function and the understanding of lead-lag systems. There is no consensus on the correct approach to the problem, and some participants express uncertainty about the definitions involved.

Contextual Notes

Participants highlight limitations in understanding the transfer function's representation and the specific requirements of the homework assignment, indicating potential dependencies on definitions and assumptions related to lead-lag systems.

gfd43tg
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Homework Statement


upload_2015-9-27_14-43-47.png

upload_2015-9-27_14-44-3.png


Homework Equations

The Attempt at a Solution


Hello,

I am trying to construct the model, but I don't know how to incorporate 3 steps. I tried making 3 step blocks, but the input for the transfer function will only take one line. Then I tried to use one step block and make a vector indicating a new step at 3 different times
upload_2015-9-27_14-47-13.png

upload_2015-9-27_14-46-29.png

But this is not working, it doesn't like the vector input. Any idea how I can utilize 3 steps?
 
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you can use a summing block and three separate step blocks.
There is also an input that will allow you to create your own waveform
 
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Thanks, I didn't know how the sum block worked before, now I do.
 
I am a bit surprised about the transfer function G(s)=(s+1)/(s+1)=1.
Who told you that this is a lead-lag block? It is a unity gain element, nothing else.
 
The homework assignment said, look at the problem statement.
 
Didn`t you realize that G(s)=1 ?
Should be a typing error; why not googling for lead-lag?
 
Yes, admittedly I don't know what lead-lag means. I was just trying to solve the problem for the homework
 
Watch point e) of the problem statement (time constants).
Time constants appear in th transfer function as factors, for eample: (s*T+1).
 

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