Can't find inverse Z transform

  • Thread starter Thread starter Addez123
  • Start date Start date
  • Tags Tags
    Inverse Transform
Click For Summary
SUMMARY

The discussion focuses on finding the inverse Z transform of the Laplace transfer function H(s) = 1/(s + 2) by converting it to H(z) using the substitution s = Ts/2*(z-1)/(z+1). The user seeks clarification on the "displacement rule" for performing the inverse Z-transform, which is essential for simplifying the transformation process. The solution involves manipulating the transformed function into a single fraction and applying Z-inversion techniques to derive the time-domain representation.

PREREQUISITES
  • Understanding of Laplace transforms and their properties
  • Familiarity with Z transforms and their applications
  • Knowledge of the displacement rule in Z-transform techniques
  • Basic skills in manipulating algebraic fractions
NEXT STEPS
  • Study the "displacement rule" in Z-transform contexts
  • Learn about the conversion process from Laplace to Z transforms
  • Explore examples of inverse Z-transform techniques
  • Review advanced engineering mathematics resources, particularly those referencing James G.'s work
USEFUL FOR

Students and professionals in engineering, particularly those studying control systems and signal processing, will benefit from this discussion. It is especially relevant for those working with Z transforms and seeking to understand their applications in time-domain analysis.

Addez123
Messages
199
Reaction score
21
New poster has been reminded to use the Homework Help Template when starting threads in the schoolwork forums

Homework Statement


I got the laplace transfer function H(s) = 1/(s + 2) and I'm suppose to find the inverse Z transform by first converting to H(z) by s = Ts/2*(z-1)/(z+1)
Then do inverse Z-transform using the "displacement rule" - Never heard of.

Homework Equations


H(s) = 1/(s + 2)
s = Ts/2*(z-1)/(z+1)

3. The Attempt at a Solution

I can't get any serious answer, and the partial z-inverse that I manage to find it's incredibly complicated (see image).
Namnl_s.png

What is this 'displacement rule' and how do I use it here?
 
Last edited:
Physics news on Phys.org
I don't have reference 17 (James G. Advanced modern engineering mathematics. Reading: Addison-Wesley; 1993.) that they refer to, but it looks like this paper ( https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5240402/ ) uses it to associate the scaled/shift inside δ(γk-λtot(t)) of equation 13 with (1/γ)ztot(t)/γ in equation 15.
Conversions like that are fairly common in transformations involving the delta function.
 
The solution was to, after replacing 's' with the Z components, then put all under one fraction sign (no plus in nominator). Then multiply with Z^-1 in bottom and top until you got only Z^- terms. This = Y(x)/X(x) which can then be translated back to y[n] and y[n-1] = Z^-1*Y(x)
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 31 ·
2
Replies
31
Views
5K