Quadratic costs do not always work in MPC

Research output: Contribution to journalArticleResearchpeer review

Authors

External Research Organisations

  • University of Stuttgart
  • Ilmenau University of Technology
View graph of relations

Details

Original languageEnglish
Pages (from-to)269-277
Number of pages9
JournalAutomatica
Volume82
Early online date22 May 2017
Publication statusPublished - 1 Aug 2017
Externally publishedYes

Abstract

We consider model predictive control (MPC) without terminal costs and constraints. Firstly, we rigorously show that MPC based on quadratic stage costs may fail, i.e., there does not exist a prediction horizon length such that a (controlled) equilibrium is asymptotically stable for the MPC closed loop although the system is, e.g., finite time controllable. Hence, stability properties of the infinite horizon optimal control problem are, in general, not preserved in MPC as long as purely quadratic costs are employed. This shows the necessity of using the stage cost as a design parameter to achieve asymptotic stability. Furthermore, we relax the standard controllability assumption employed in MPC without terminal costs and constraints to alleviate its verification.

Keywords

    Asymptotic stabilization, Mobile robots, Model predictive control, Nonlinear systems, Quadratic costs

ASJC Scopus subject areas

Cite this

Quadratic costs do not always work in MPC. / Müller, Matthias A.; Worthmann, Karl.
In: Automatica, Vol. 82, 01.08.2017, p. 269-277.

Research output: Contribution to journalArticleResearchpeer review

Müller MA, Worthmann K. Quadratic costs do not always work in MPC. Automatica. 2017 Aug 1;82:269-277. Epub 2017 May 22. doi: 10.1016/j.automatica.2017.04.058
Müller, Matthias A. ; Worthmann, Karl. / Quadratic costs do not always work in MPC. In: Automatica. 2017 ; Vol. 82. pp. 269-277.
Download
@article{1e4a1072733c4d76a7eabe1ba55ec5a0,
title = "Quadratic costs do not always work in MPC",
abstract = "We consider model predictive control (MPC) without terminal costs and constraints. Firstly, we rigorously show that MPC based on quadratic stage costs may fail, i.e., there does not exist a prediction horizon length such that a (controlled) equilibrium is asymptotically stable for the MPC closed loop although the system is, e.g., finite time controllable. Hence, stability properties of the infinite horizon optimal control problem are, in general, not preserved in MPC as long as purely quadratic costs are employed. This shows the necessity of using the stage cost as a design parameter to achieve asymptotic stability. Furthermore, we relax the standard controllability assumption employed in MPC without terminal costs and constraints to alleviate its verification.",
keywords = "Asymptotic stabilization, Mobile robots, Model predictive control, Nonlinear systems, Quadratic costs",
author = "M{\"u}ller, {Matthias A.} and Karl Worthmann",
note = "Funding information: M.A. M{\"u}ller and K. Worthmann are supported by the Deutsche Forschungsgemeinschaft, Grants WO 2056/1-1 and WO 2056/4-1. The material in this paper was not presented at any conference. This paper was recommended for publication in revised form by Associate Editor Giancarlo Ferrari-Trecate under the direction of Editor Ian R. Petersen.",
year = "2017",
month = aug,
day = "1",
doi = "10.1016/j.automatica.2017.04.058",
language = "English",
volume = "82",
pages = "269--277",
journal = "Automatica",
issn = "0005-1098",
publisher = "Elsevier Ltd.",

}

Download

TY - JOUR

T1 - Quadratic costs do not always work in MPC

AU - Müller, Matthias A.

AU - Worthmann, Karl

N1 - Funding information: M.A. Müller and K. Worthmann are supported by the Deutsche Forschungsgemeinschaft, Grants WO 2056/1-1 and WO 2056/4-1. The material in this paper was not presented at any conference. This paper was recommended for publication in revised form by Associate Editor Giancarlo Ferrari-Trecate under the direction of Editor Ian R. Petersen.

PY - 2017/8/1

Y1 - 2017/8/1

N2 - We consider model predictive control (MPC) without terminal costs and constraints. Firstly, we rigorously show that MPC based on quadratic stage costs may fail, i.e., there does not exist a prediction horizon length such that a (controlled) equilibrium is asymptotically stable for the MPC closed loop although the system is, e.g., finite time controllable. Hence, stability properties of the infinite horizon optimal control problem are, in general, not preserved in MPC as long as purely quadratic costs are employed. This shows the necessity of using the stage cost as a design parameter to achieve asymptotic stability. Furthermore, we relax the standard controllability assumption employed in MPC without terminal costs and constraints to alleviate its verification.

AB - We consider model predictive control (MPC) without terminal costs and constraints. Firstly, we rigorously show that MPC based on quadratic stage costs may fail, i.e., there does not exist a prediction horizon length such that a (controlled) equilibrium is asymptotically stable for the MPC closed loop although the system is, e.g., finite time controllable. Hence, stability properties of the infinite horizon optimal control problem are, in general, not preserved in MPC as long as purely quadratic costs are employed. This shows the necessity of using the stage cost as a design parameter to achieve asymptotic stability. Furthermore, we relax the standard controllability assumption employed in MPC without terminal costs and constraints to alleviate its verification.

KW - Asymptotic stabilization

KW - Mobile robots

KW - Model predictive control

KW - Nonlinear systems

KW - Quadratic costs

UR - http://www.scopus.com/inward/record.url?scp=85019350974&partnerID=8YFLogxK

U2 - 10.1016/j.automatica.2017.04.058

DO - 10.1016/j.automatica.2017.04.058

M3 - Article

VL - 82

SP - 269

EP - 277

JO - Automatica

JF - Automatica

SN - 0005-1098

ER -

By the same author(s)