An approximate inverse system for nonminimum-phase systems and its application to disturbance observer
- 作者：Chen ; Xinkai ; Zhai ; Guisheng ; Fukuda ; Toshio
- 关键词：Approximate inverse system ; Least-square approximation ; Nonminimum-phase dynamical systems ; Disturbance observer ; Multivariable systems
- 刊名：Systems and Control Letters
- 出版年：2004
- 期刊代码：171_01676911
- 类别：et
- 出版时间：July, 2004
- 卷：52
- 期：3-4
- 页码：193-207
- 文件大小：294 K
摘要
This paper proposes an approximate inverse system for nonminimum-phase dynamical systems based on the least-square approximation method. The nonminimum-phase systems are approximated by minimum-phase systems. The proposed formulation is applied to the disturbance observation problems for multivariable nonminimum-phase systems with arbitrary relative degrees. The disturbances, which are assumed bounded, are the combination of the external disturbances, the nonlinearities and the model uncertainties of the system. The estimation error of the disturbances is controlled by the design parameters. Furthermore, the accuracy of the estimation also depends on the frequencies of the disturbances. Simulation results show the effectiveness of the proposed method.