Control horizon

[Antonio]

Yes, I think it will help to solve the OCP faster.

@FreyJo

This can be implemented in acados by using a nonuniform grid and setting the time between the last 2 shooting nodes larger compared to the previous ones.
In order to achieve the same integration accuracy, you could use more steps in the last integrator.

Could you show me an example of how to do that in the Matlab interface? It would be very helpful.

If I understood correctly, we have a time grid [t0,t1,t2,…tN] in which we discretize the
controls to obtain piecewise constant controls, and we use the integrator to solve the ODE in the interval [tk, tk+1] of the same grid. For that reason control horizon and prediction horizon are always the same. Isn’t it?

@FreyJo

In order to achieve the same integration accuracy, you could use more steps in the last integrator.

I suposse you refer the option sim_method_num_steps in the matlab interface. Could you explain what that option means?
I think it means that, if you have a time grid [t0,t1,t2,…tN] in which we discretize the
controls, and for example if the number of steps of the integrator is 3, in the interval [t1,t2], we have a constant piecewise control, but we solve 3 ODEs in [t1, (t1+t2)/2, t2]
Is it correct?

Thanks in advance, sorry for the inconveniences and for writing such a long question.