Including algebraic variables as input in formulation of discrete dynamics is supported?

User Questions
1

Hello,
I am wondering whether including algebraic variables in formulation of discrete dynamics is supported? It seems that the answer is no according to the following document, because I want algebraic variables on the LHS.

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taken from https://www.syscop.de/files/2021ss/acados_workshop/2021_FOR_workshop.pdf

Or is there any work around? I want to include some term (algebraic variables) which are functions of control inputs and states in one horizon, and the term will also be used in the time integration of the prediction of next horizon. This process repeats until the final horizon.

Thanks a lot in advance!:slight_smile:

2

Hi,

unfortunately, this is not supported for now.
It is probably possible to just use the expression where ever it is needed but that is probably not ideal in terms of computational performance.

3

Hello,
Thanks a lot for the instant reply. Could you please clarify a little what you mean by “It is probably possible to just use the expression where ever it is needed” ? The term (algebraic variables) I want to use is used also in the formulation of the dynamic equations and subsequent optimization , do you mean that I treat the term as state variables (x) ?