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 language||English (US)|
|Number of pages||15|
|Journal||International Journal of Robust and Nonlinear Control|
|State||Published - Mar 10 2018|
Bibliographical noteFunding Information:
National Science Foundation, Grant/Award Number: CMMI 1562006; EPI Inria DISCO; L2S; CentraleSupélec
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.
- automotive control
- bilinear matrix inequality
- convex optimization
- nonlinear system
- output feedback
- robust control