Adding initial conditions in a transfer function/block

Specific domains Modeling and simulation
1

Good afternoon, everyone

I have a question, and hopefully someone can assist me with it

Is it possible to specify initial conditions for a transfer function in the XCOS ? I have a model with a numerator of 1 and a denominator of s^2 + 1s + 2. The model contains various blocks like a step block, PID block, sum block, transfer block, mux, clock, and a scope.

Within the transfer block, there doesn’t seem to be an option to set initial conditions. I want to set the initial velocity to 2 m/s and the initial position to 1 meter. I am aware that for state space models, integrator blocks, and gains, you can set these initial conditions.

Could someone guide me on how to achieve this? I have attached the model for reference.

Vraag
Vraag1150×376 11 KB

Thank you in advance.

ADG

2

Hello,

As you said, the “Continuous transfer function” block does not allow to set any initial condition. Of course, this block is implemented as a state-space system inside Xcos, but if you want to be able to set initial conditions you have to use a “Continuous state-space system” (or build your system with integrators, which have also an initial condition field). The following statement on Scilab’s command line will give you the matrices:

tf2ss(1/(%s^2+%s+2))

S.