Set yref at node 0

aceglia · June 10, 2022, 6:07pm

Hi

I’m using the python interface of Acados for an MHE problem and I try to add mayer terms only on node 0. So the size of yref will not be the same at node 0 and node [1:N-1]. I know it’s allowed to have different sizes for node N and [1:N-1] but I’m not sure for node 0.

When I try to set yref (see code below) for node 0 I have an error message saying that the shape is different between yref and yref_0

ocp_solver.cost_set(0, "yref", yref_0)

Is it possible in another way or do Acados not let set yref at different sizes?

Thanks a lot.

Amedeo

FreyJo · June 11, 2022, 4:53pm

Hi,

you need to define the cost at stage 0 separately I think.
I suggest you go through this MHE example:

github.com

acados/acados/blob/406c0e702fab7a680825c2b75916b626ef1e6282/examples/acados_python/getting_started/mhe/export_mhe_solver.py

#
# Copyright 2019 Gianluca Frison, Dimitris Kouzoupis, Robin Verschueren,
# Andrea Zanelli, Niels van Duijkeren, Jonathan Frey, Tommaso Sartor,
# Branimir Novoselnik, Rien Quirynen, Rezart Qelibari, Dang Doan,
# Jonas Koenemann, Yutao Chen, Tobias Schöls, Jonas Schlagenhauf, Moritz Diehl
#
# This file is part of acados.
#
# The 2-Clause BSD License
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#

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github.com

acados/acados/blob/406c0e702fab7a680825c2b75916b626ef1e6282/examples/acados_python/getting_started/mhe/closed_loop_mhe_ocp.py

# -*- coding: future_fstrings -*-
#
# Copyright 2019 Gianluca Frison, Dimitris Kouzoupis, Robin Verschueren,
# Andrea Zanelli, Niels van Duijkeren, Jonathan Frey, Tommaso Sartor,
# Branimir Novoselnik, Rien Quirynen, Rezart Qelibari, Dang Doan,
# Jonas Koenemann, Yutao Chen, Tobias Schöls, Jonas Schlagenhauf, Moritz Diehl
#
# This file is part of acados.
#
# The 2-Clause BSD License
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.

This file has been truncated. show original

Cheers!

aceglia · July 21, 2022, 9:35pm

Hi,

Thanks @FreyJo for your quick response! My mistake was that I forgot to set the “cost_type_0” so when the program compiles it just erases everything related to my initial node.

Everything works well now.

Cheers