Hybrid neural network controller for uncertain nonlinear discrete-time systems with non-symmetric dead zone and unknown disturbances

ABSTRACT

An adaptive hybrid neural control scheme is presented for uncertain non-linear discrete-time Systems (UNLDTS) with non-symmetric dead-zone input and unknown disturbances. This work aims to design an efficient control scheme for the proposed systems in the case of non-symmetric dead-zone as the input due to the presence of which the control of such systems becomes very complex and difficult. The system is converted into an n-step ahead predictor and an adaptive compensative term is introduced to overcome the non-symmetric dead-zone present in the system. A hybrid neural network controller is constructed for the control of the proposed class of systems. The designed controller is proved to be semi-globally uniformly ultimately bounded with the assistance of Lyapunov theory and the error is proved to approach very close to zero. The effectiveness of the proposed scheme is validated through two simulation examples and one example has been inspired from a real word system named continuous stirred tank reactor taken in discrete-time form which ensures the applicability of this controller in real-world applications.

KEYWORDS:

• Hybrid neural network
• non-linear uncertain systems
• Lyapunov method
• external disturbances
• particle swarm optimization
• continuous stirred tank reactor (CSTR)

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by MATRICS project grant No. MTR/2021/000Q4478 from the Science and Engineering Research Board (SERB), India.