A switched extremum seeking control without steady-state oscillation using gradient-based adaptive-amplitude perturbation

Minghui Chu; Xin Huo; Kemao Ma; Weizhen Liu

doi:10.1016/j.isatra.2023.06.036

A switched extremum seeking control without steady-state oscillation using gradient-based adaptive-amplitude perturbation

ISA Trans. 2023 Oct:141:314-325. doi: 10.1016/j.isatra.2023.06.036. Epub 2023 Jul 4.

Authors

Minghui Chu¹, Xin Huo², Kemao Ma¹, Weizhen Liu¹

Affiliations

¹ Control and Simulation Center, School of Astronautics, Harbin Institute of Technology, Harbin 150001, China.
² Control and Simulation Center, School of Astronautics, Harbin Institute of Technology, Harbin 150001, China. Electronic address: huoxin@hit.edu.cn.

PMID: 37479595
DOI: 10.1016/j.isatra.2023.06.036

Abstract

To enhance the steady-state and dynamic performance of the extremum seeking control (ESC), a switched ESC scheme is proposed in this paper. Firstly, to solve nonconvex optimization problems, a novel adaptive law for perturbation is established utilizing the hybrid gradient information to accomplish a trade-off between the dynamic and steady-state performance. It is shown that the adaptive-amplitude ESC achieves global optimization despite the existence of local extrema. Then, to overcome the adverse effect of inaccurate gradient estimation on steady-state accuracy, a Lyapunov-based switched strategy is employed to start the bisection-based ESC. The plant output converges to the equilibrium rapidly and accurately without steady-state oscillation. Furthermore, the stability of the proposed scheme is theoretically proved. Numerical simulation examples are carried out to demonstrate the effectiveness of the proposed scheme.

Keywords: Adaptive amplitude; Bisection method; Hybrid gradient information; Switched ESC.