transfer fuction representation needed

 采纳的回答

Stephan
Stephan 2019-3-5
编辑:Stephan 2019-3-5
Hi,
this is a compact way to express 1 transfer function with 3 inputs and convert it to a state space representation.You can find this also as an similar example in the documentation of tf function for the case of 2 outputs. Consider:
>> sys = tf({1,1,1},{[1 .5 1],[1 1],[.7 .5 1]})
sys =
From input 1 to output:
1
---------------
s^2 + 0.5 s + 1
From input 2 to output:
1
-----
s + 1
From input 3 to output:
1
-------------------
0.7 s^2 + 0.5 s + 1
Continuous-time transfer function.
Now with the ss function, the 1x3 transfer function is converted to the correspondig state space representation of the system:
>> sys = ss(sys)
sys =
A =
x1 x2 x3 x4 x5
x1 -0.5 -1 0 0 0
x2 1 0 0 0 0
x3 0 0 -1 0 0
x4 0 0 0 -0.7143 -1.429
x5 0 0 0 1 0
B =
u1 u2 u3
x1 1 0 0
x2 0 0 0
x3 0 1 0
x4 0 0 1
x5 0 0 0
C =
x1 x2 x3 x4 x5
y1 0 1 1 0 1.429
D =
u1 u2 u3
y1 0 0 0
Continuous-time state-space model.
The code you posted in your question just combines both steps in one line of code.
sys = ss(tf({1,1,1},{[1 .5 1],[1 1],[.7 .5 1]}));
Best regards
Stephan

3 个评论

Respected Stephan first of all thanks for spending your precious time for answering, actually I searched many sites but couldn't find the solution. You explained very briefly in detail. If interested then I want to get associated with you academically to enhance my skills...
I think the better way is that you post questions here in the forum, to let others learn from them also.
sys = ss(sys)
sys =
A =
x1 x2 x3 x4 x5
x1 -0.5 -1 0 0 0
x2 1 0 0 0 0
x3 0 0 -1 0 0
x4 0 0 0 -0.7143 -1.429
x5 0 0 0 1 0
B =
u1 u2 u3
x1 1 0 0
x2 0 0 0
x3 0 1 0
x4 0 0 1
x5 0 0 0
C =
x1 x2 x3 x4 x5
y1 0 1 1 0 1.429
D =
u1 u2 u3
y1 0 0 0
can u explain what do you mean by sys=ss(sys), i want to know the value of (sys) in sys=ss(sys)?
even about a,b,c,d values..

请先登录,再进行评论。

更多回答(0 个)

类别

帮助中心File Exchange 中查找有关 Dynamic System Models 的更多信息

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by