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Active Disturbance Rejection in Affine Nonlinear Systems Based on Equivalent‐Input‐Disturbance Approach |
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| Authors: | Fang Gao Min Wu Jinhua She Weihua Cao |
| Affiliation: | 1. School of Information Science and Engineering, Central South University, Changsha, China;2. Hubei key Laboratory of Advanced Control and Intelligent Automation for Complex Systems, Wuhan, China;3. School of Automation, China University of Geosciences, Wuhan, China;4. School of Engineering, Tokyo University of Technology, Hachioji, Japan |
| Abstract: | This paper presents a disturbance rejection method for an affine nonlinear system. The control system is constructed based on the equivalent‐input‐disturbance (EID) approach. An affine nonlinear state observer is used to reconstruct the state of the affine nonlinear system and to estimate an EID. The well‐known differential mean value theorem enables us to describe the closed‐loop system in the state space as a linear‐parameter‐varying system. This makes it easy to derive sufficient conditions of global uniform ultimate boundedness in term of linear matrix inequalities (LMIs) by using a Lyapunov function and convexity theory. Controllers are designed based on the LMIs. A numerical example is used to illustrate the design of the control system. And a comparison between the EID‐based control and the sliding‐mode control demonstrates the effectiveness and advantages of the EID‐based control method. |
| Keywords: | disturbance rejection equivalent input disturbance (EID) linear matrix inequality (LMI) differential mean value theorem affine nonlinear system |
