Combine two different size matrix in state equations

[khedira]

i have two sets of state equations:

1) x(dot) = (2x2)x + (2x1)u
y = (1x2)x

2) x(dot) = (0)x + (1x1)u
y = (1x1)x

given the above, since A, B and C are of different sizes, how can i add the A from 1) and 2) to get a combined A? Is that possible? Please advise. Thank you.

 

[lanedance]

what are A, B & C? can you explain better?

also what are x,y & u are these 2x1 column vectors etc.

 

[khedira]

what are A, B & C? can you explain better?

also what are x,y & u are these 2x1 column vectors etc.

Hi lanedance,

Thank you for your reply. I confused myself and is able to get the answer already.

The problem was that i have this A1 2x2 matrix, e.g. [1 2; 3 4] and i have another A2 1x1 matrix [5]. I wish to add them together, i.e. A = A1 + A2. At first i thought that the size different between A1 and A2 make it impossible to directly add them up. Then i realize that since A2 is in scalar form, A = A1 + A2 = [6 7; 8 9].

Thank you for your reply anyway.

 

[lanedance]

yeah that doesn't seem quite right, maybe if its A2*I , where I is the identity matrix it works