MISO State-space Model

Hi, I have a state-space model with 1 input and 1 output that works just fine. I want to change one of the constants in that model to an input, which is to be determined by a controller. I have the model in state-space and i have it modelled in SIMULINK. I know how to change it in SIMULINK but I don't know how to change the state-space model. Help is very much appreciated :)

Answer 1

[Arnaud Miege]

I assume that you are using the State-Space block. You'll need to reconstruct your state-space model using basic Simulink blocks. Have a look at the following:

• How Do I Change a Block Parameter Based on the Output of Another Block?
• How do I model a transfer function with coefficients that vary with simulation time in Simulink 7.5 (R2010a)?

HTH,

Arnaud

[RZ]

Hi Arnaud,

Thanks for your reply. I used exactly that technique. I replaced a gain block which represented the damping coefficient with an input and product block so I can enter the damping coefficient manually, or control it using some form of a controller I would design later. However, when I try to convert the system into a state-space block using the "linmod" function in matlab, it doesn't work. It gives me the state-space matrices, and when I use them in the state-space block in SIMULINK I get a wrong output. It seems that the model is taking only the first input and assuming the 2nd is zero. But the model still requires 2 inputs or it gives me an error. Is it possible to send you the files so you can check them for yourself?

Thanks alot for your help.

[Arnaud Miege]

Could you upload the files on a filesharing site instead? Then, they're accessible to the rest of the community.