Computational Technology Resources - CCP

Keywords: chaos, compliant offshore systems, Lyapunov stability, Krasovskii-LaSalle principle, genetic algorithm, Duffing equation.

Summary

In this paper, a new geometrical theory based control scheme with nontraditional optimization algorithm is used to achieve the chaos harmonization for compliant offshore systems. It is known that the compliant offshore structures are usually located in a severe environment. The behavior of the compliant offshore systems is usually modeled by nonlinear oscillators. These structures experience chaotic responses due to internal nonlinear restoring and damping forces and external wave excitations. The performance of these structures is dependent on the motions being in a state of order and within operational limits. To achieve the same, a recursive back stepping control mechanism is proposed for controlling the compliant systems. Using the Lyapunov stability theory, two additional functionals of displacement and velocity are introduced to achieve the desired output. Each of these functionals have two (depending upon the order of the system) controlling parameters that are linked with the damping and frequencies of the offshore structure. The parameters are obtained using the genetic algorithm (GA) and the Krasovskii-LaSalle principle. The Krasovskii-LaSalle principle provides positive parameter values essential for global convergence in the algorithm. The optimal value of these parameters is ensured using the GA which is based on the evolutionary algorithms that minimizes the objective function. The performance of the controller is compared with classical design based on the Krasovskii-LaSalle principle. The performance of the GA based back stepping control strategy is illustrated using a nonlinear Duffing equation. The results show that controller was able to restrict the undesirable chaotic behaviour and also provide means of shaping the transient performance.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £65 +P&P)

	Computational & Technology Resources an online resource for computational, engineering & technology publications
	not logged in - login
Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 102 PROCEEDINGS OF THE FOURTEENTH INTERNATIONAL CONFERENCE ON CIVIL, STRUCTURAL AND ENVIRONMENTAL ENGINEERING COMPUTING Edited by: Paper 43 Synchronization of Chaotic Compliant Ocean Systems using a Genetic Algorithm based Backstepping Approach R. Manikandan and N. Saha Department of Ocean Engineering Indian Institute of Technology Madras, Chennai, India doi:10.4203/ccp.102.43 purchase the full-text of this paper Full Bibliographic Reference for this paper R. Manikandan, N. Saha, "Synchronization of Chaotic Compliant Ocean Systems using a Genetic Algorithm based Backstepping Approach", in , (Editors), "Proceedings of the Fourteenth International Conference on Civil, Structural and Environmental Engineering Computing", Civil-Comp Press, Stirlingshire, UK, Paper 43, 2013. doi:10.4203/ccp.102.43 Keywords: chaos, compliant offshore systems, Lyapunov stability, Krasovskii-LaSalle principle, genetic algorithm, Duffing equation. Summary In this paper, a new geometrical theory based control scheme with nontraditional optimization algorithm is used to achieve the chaos harmonization for compliant offshore systems. It is known that the compliant offshore structures are usually located in a severe environment. The behavior of the compliant offshore systems is usually modeled by nonlinear oscillators. These structures experience chaotic responses due to internal nonlinear restoring and damping forces and external wave excitations. The performance of these structures is dependent on the motions being in a state of order and within operational limits. To achieve the same, a recursive back stepping control mechanism is proposed for controlling the compliant systems. Using the Lyapunov stability theory, two additional functionals of displacement and velocity are introduced to achieve the desired output. Each of these functionals have two (depending upon the order of the system) controlling parameters that are linked with the damping and frequencies of the offshore structure. The parameters are obtained using the genetic algorithm (GA) and the Krasovskii-LaSalle principle. The Krasovskii-LaSalle principle provides positive parameter values essential for global convergence in the algorithm. The optimal value of these parameters is ensured using the GA which is based on the evolutionary algorithms that minimizes the objective function. The performance of the controller is compared with classical design based on the Krasovskii-LaSalle principle. The performance of the GA based back stepping control strategy is illustrated using a nonlinear Duffing equation. The results show that controller was able to restrict the undesirable chaotic behaviour and also provide means of shaping the transient performance. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £65 +P&P)
Back to top	©Civil-Comp Limited 2023 - terms & conditions