How can I avoid Algebraic loops In these equations

Hi,

I Have two equations of the form-

1) dy/dt = A - By - Cdx/dt + Dx, and

2) dx/dt = E - Fx - Gdy/dt + Hy.

I want to apply them in a Simulink model, Is there any way I can do it without using Algebraic loops?

Thanks

Answer 1

[A Jenkins]

If you are smart about it, you may be able to avoid a memory block. Depending on the properties of your numbers (for example, if 1+GC is invertible), you may be able to rewrite the equations:

dy/dt = A-B*y-C*(dx/dt)+D*x

dx/dt = E-F*x-G*(dy/dt)+H*y

dx/dt = E-F*x-G*(A-B*y-C*(dx/dt)+D*x)+H*y

dx/dt = (E-F*x-G*(A-B*y+D*x)+H*y)/(1+GC)

[Anuj]

Thanks for your suggestion, I didn't think this way.

Answer 2

[Mischa Kim]

Hello Anuj, see http://www.mathworks.de/matlabcentral/answers/34478-is-this-the-way-to-solve-algebraic-loops.

[Anuj]

That one suggests to include delay or memory, but in the above system how will i use delay/memory?