Anti-disturbance control based on nonlinear disturbance observer for a class of stochastic systems

• Published in: Transactions of the Institute of Measurement and Control Vol. 41; no. 6; pp. 1665 - 1675
• Main Authors: Dong, Lewei, Wei, Xinjiang, Zhang, Huifeng
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01-04-2019; Sage Publications Ltd
• Subjects: Active control; Attenuation; Computer simulation; Disturbance observers; Dynamical systems; Feedback control; H-infinity control; Nonlinear control; Nonlinear dynamics; Nonlinear systems; Stochastic systems; White noise; nonlinear exosystem; stochastic system; NDOBDAC; multiple disturbances; anti-disturbance control
• ISSN: 0142-3312; 1477-0369
• DOI: 10.1177/0142331218787608

In engineering, there exist lots of nonlinear disturbance dynamics, which can be described by nonlinear exogenous systems. The current stochastic linear disturbance observer is conservative and is not applicable for nonlinear disturbance dynamics. This paper studies a class of stochastic systems with multiple disturbances, including white noise and disturbances modelled by a nonlinear exogenous system. To estimate the disturbance with nonlinear dynamics, a stochastic nonlinear disturbance observer is proposed. Based on the observer, a nonlinear disturbance observer-based disturbance attenuation control (NDOBDAC) scheme is constructed such that the composite closed-loop system is asymptotically mean-square bounded. According to the simulation example, the state responses of the system diverge in the absence of control, but it tends to be
±
0
.
01
under NDOBDAC, which demonstrates the effectiveness of the proposed scheme. In addition, the anti-disturbance control accuracy of NDOBDAC approximately improves
60
~
200
times compared with
H
∞
control and active disturbance rejection control (ADRC). The simulation results demonstrate the feasibility and effectiveness of the proposed scheme.