Adaptive control of a class of discrete-time MIMO nonlinear systems with uncertain couplings

Abstract

In this article, adaptive control is investigated for a class of discrete-time multi-input-multi-output nonlinear systems in block-triangular form with uncertain couplings of delayed states among subsystems. Future states prediction is carried out to facilitate adaptive control design and auxiliary outputs are introduced to develop a novel compensation mechanism for the uncertain nonlinear couplings. By using Lyapunov method and ordering signals growth rate, it is rigorously proved that all the signals in the whole closed-loop systems are globally bounded and the output tracking errors asymptotically converge to zeros. The effectiveness of the proposed control is demonstrated in the simulation study.

Keywords:

• adaptive control
• MIMO discrete-time systems
• couplings

Acknowledgements

The authors thank Dr Hongbin Ma for his helpful comments. This work was partially supported by the National Nature Science Foundation of China under Grants 61004059 and 60904086.