How to obtain statespace having two inputs from transfer function in matlab mfile

I am having a transfer function having two zeros and four poles.

    G(s)=   (as^2+bs+c)/(s^4+ds^3+es^2 )

I need to convert TF to statespace such that it has two inputs i.e. matrix B has two columns.I know the commands tf2ss but it gives me statespace with one input.

Answer 1

[Azzi Abdelmalek]

Use tf2ss to find A,B,C,D , change B to add any inputs you want, then rebuilt a newmodel with ss function

a=1;b=2;c=1;
d=1;e=1;
N=[a b c];
D=[1 d e 0 0];
[A,B,C,D]=tf2ss(N,D)
B=[B [1;0;0;0]]
new_model=ss(A,B,C,D)

Answer 2

[Teja Muppirala]

How about:

s = tf('s');
G=   (s^2+s+1)/(s^4+s^3+s^2 );

Gss = ss([G G]);

Although I don't quite see the point in having two inputs to the same system (you could just add them together and get the same response).