Laplace inversion for fractional-order transfer functions
7 views (last 30 days)
Show older comments
Ehsan Khorsandnejad
on 11 Feb 2019
Answered: Patel Mounika
on 20 Feb 2019
I am using the FOMCON toolbox, which enables me to introduce transfer functions with a fractional order. However, when I want to use the laplace inversion function, it works for simple cases but not for a bit complicated equations. Can anyone help me with this?
Example 1: works
syms s
TF = 1/s^0.5;
ilaplace(TF)
ans =
1/(t^(1/2)*pi^(1/2))
Example 2: does not work (only works when a = integer)
syms s
a = 0.5
TF = 1/(5 + (3*(s^a + (1/2^a)))/(s^a + (1/6^a)));
ilaplace(TF)
answ =
ilaplace(1/(((3*2^(1/2))/2 + 3*s^(1/2))/(6^(1/2)/6 + s^(1/2)) + 5), s, t)
0 Comments
Accepted Answer
Patel Mounika
on 20 Feb 2019
The ilaplace function of the symbolic engine currently does not implement an explicit expression for
ilaplace(1/(5 + (3*(s^a + (1/2^a)))/(s^a + (1/6^a)))) if a is not an integer .
The ilaplace function computes the analytic closed inverse Laplace form of a transfer function. It seems that mathematically a closed inverse Laplace form for 1/(5 + (3*(s^a + (1/2^a)))/(s^a + (1/6^a))) for general a cannot be found out, so ilaplace function will not simplify it further.
Nevertheless, there is a community submission at MathWorks File Exchange which numerically approximates an inverse Laplace transform for any function of "s". Following is the link of the same:
0 Comments
More Answers (0)
See Also
Categories
Find more on Calculus in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!