# NONLINEAR SYSTEM IDENTIFICATION USING DISCRETE-TIME NEURAL NETWORKS WITH STABLE LEARNING ALGORITHM

### Talel Korkobi, Mohamed Djemel, Mohamed Chtourou

#### Abstract

This paper presents a stable neural sytem identification for nonlinear systems. An input output discrete time representation is considered. No a priori knowledge about the nonlinearities of the system is assumed. The proposed learning rule is the backpropagation algorithm under the condition that the learning rate belongs to a specified range defining the stability domain. Satisfying such condition, unstable phenomenon during the learning process is avoided. A Lyapunov analysis is made in order to extract the new updating formulation which contain a set of inequality constraints. In the constrained learning rate algorithm, the learning rate is updated at each iteration by an equation derived using the stability conditions. As a case study, identification of two discrete time systems is considered to demonstrate the effectiveness of the proposed algorithm. Simulation results concerning the considered systems are presented.

#### References

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#### Paper Citation

#### in Harvard Style

Korkobi T., Djemel M. and Chtourou M. (2008). **NONLINEAR SYSTEM IDENTIFICATION USING DISCRETE-TIME NEURAL NETWORKS WITH STABLE LEARNING ALGORITHM** . In *Proceedings of the Fifth International Conference on Informatics in Control, Automation and Robotics - Volume 1: ICINCO,* ISBN 978-989-8111-30-2, pages 351-356. DOI: 10.5220/0001504403510356

#### in Bibtex Style

@conference{icinco08,

author={Talel Korkobi and Mohamed Djemel and Mohamed Chtourou},

title={NONLINEAR SYSTEM IDENTIFICATION USING DISCRETE-TIME NEURAL NETWORKS WITH STABLE LEARNING ALGORITHM},

booktitle={Proceedings of the Fifth International Conference on Informatics in Control, Automation and Robotics - Volume 1: ICINCO,},

year={2008},

pages={351-356},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0001504403510356},

isbn={978-989-8111-30-2},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the Fifth International Conference on Informatics in Control, Automation and Robotics - Volume 1: ICINCO,

TI - NONLINEAR SYSTEM IDENTIFICATION USING DISCRETE-TIME NEURAL NETWORKS WITH STABLE LEARNING ALGORITHM

SN - 978-989-8111-30-2

AU - Korkobi T.

AU - Djemel M.

AU - Chtourou M.

PY - 2008

SP - 351

EP - 356

DO - 10.5220/0001504403510356