Robustness Analysis of Discrete-time Indirect Model Reference Adaptive Control with Normalized Adaptive Laws

• Published in: International journal of automation and computing Vol. 7; no. 3; pp. 381 - 388
• Main Author: Qing-Zheng Gao Xue-Jun Xie
• Format: Journal Article
• Language: Chinese
• Published: 2010
• Subjects: MRAC方案; 参数估计算法; 模型参考自适应控制; 离散信号; 离散时间系统; 自适应律; 间接型; 鲁棒性分析
• ISSN: 1476-8186; 1751-8520

For a class of discrete-time systems with unmodeled dynamics and bounded disturbance, the design and analysis of robust indirect model reference adaptive control （MRAC） with normalized adaptive law are investigated. The main work includes three parts. Firstly, it is shown that the constructed parameter estimation algorithm not only possesses the same properties as those of traditional estimation algorithms, but also avoids the possibility of division by zero. Secondly, by establishing a relationship between the plant parameter estimate and the controller parameter estimate, some similar properties of the latter are also established. Thirdly, by using the relationship between the normalizing signal and all the signals of the closed-loop system, and some important mathematical tools on discrete-time systems, as in the continuous-time case, a systematic stability and robustness analysis approach to the discrete indirect robust MRAC scheme is developed rigorously.