I have implemented a NMPC trajectory tracking controller in Casadi and I am trying to transfer my problem over to Acados for real time use, using the Python interface. Since my reference is time-varying, I am trying to set yref and yref_e for each stage like in the MATLAB interface. But as far as I can tell there is no way to set yref_e. I have tried setting yref at stage N instead (as they do in the racecar example) but from the resulting solver solution the initialized yref_e value is still the one the solver uses. Furthermore, the final state completely disregards the state bounds! Am I doing something wrong here? Is it possible to use the EXTERNAL cost type and let the time varying reference be a parameter value and set that instead in order to implement trajectory tracking?
Help greatly appreciated, thanks!