Sequential LMI approach for the design of a BMI-based robust observer state feedback controller with nonlinear uncertainties

Yan Wang, Rajesh Rajamani, Ali Zemouche

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


This paper aims at developing a robust observer–based estimated state feedback control design method for an uncertain dynamical system that can be represented as a linear time-invariant system connected with an integral quadratic constraint–type nonlinear uncertainty. Traditionally, in existing design methodologies, a convex semidefinite constraint is obtained at the cost of conservatism and unrealistic assumptions. This paper avoids such assumptions and formulates, the design of the robust observer state feedback controller as the feasibility problem of a bilinear matrix inequality (BMI) constraint. Unfortunately, the search for a feasible solution of a BMI constraint is an NP-hard problem in general. The applicability of a linearization method, such as the variable change method and the congruence transformation, depends on the specific structure of the problem at hand and cannot be generalized. This paper transforms the feasibility analysis of the BMI constraint into an eigenvalue problem and applies the convex-concave–based sequential linear matrix inequality optimization method to search for a feasible solution. Furthermore, an augmentation of the sequential linear matrix inequality algorithm to improve its numerical stability is presented. In the application part, a vehicle lateral control problem is presented to demonstrate the applicability of the proposed algorithm to a real-world estimated state feedback control design problem and the necessity of the augmentation for numerical stability.

Original languageEnglish (US)
Pages (from-to)1246-1260
Number of pages15
JournalInternational Journal of Robust and Nonlinear Control
Issue number4
StatePublished - Mar 10 2018

Bibliographical note

Funding Information:
National Science Foundation, Grant/Award Number: CMMI 1562006; EPI Inria DISCO; L2S; CentraleSupélec

Funding Information:
This work was supported in part through funding from the National Science Foundation under Grant CMMI 1562006 and was also supported in part by the EPI Inria DISCO, L2S, CentraleSupélec, during the academic position (Délégation Inria) of A. Zemouche from September 2016 to August 2017.

Publisher Copyright:
Copyright © 2017 John Wiley & Sons, Ltd.


  • automotive control
  • bilinear matrix inequality
  • convex optimization
  • nonlinear system
  • output feedback
  • robust control


Dive into the research topics of 'Sequential LMI approach for the design of a BMI-based robust observer state feedback controller with nonlinear uncertainties'. Together they form a unique fingerprint.

Cite this