Design of optimal length low-dispersion FBG filter using covariance matrix adapted evolution
ABSTRACT The design of a low-dispersion fiber Bragg grating (FBG) with an optimal grating length using covariance matrix adapted evolution strategy (CMAES) is presented. A novel objective function formulation is proposed for the optimal grating length low-dispersion FBG design. The CMAES algorithm employs adaptive learning procedure to identify correlations among the design parameters. The design of a low-dispersion FBG filter with 25-GHz (or 0.2 nm in the 1550-nm band) bandwidth is considered. Simulation results, obtained using the codes available in public domain (the codes are available from the third author), show that the CMAES algorithm is more appropriate for the practical design of length optimized FBG-based filters when compared with the other optimization methods.
- SourceAvailable from: scielo.brJournal of Microwaves, Optoelectronics and Electromagnetic Applications. 06/2011; 10(1):165-178.
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ABSTRACT: In this paper, design of centralized PID controller using Covariance Matrix Adaptation Evolution Strategy (CMAES) is presented. Binary distillation column plant described by Wood and Berry (WB) having two inputs and two outputs and by Ogunnike and Ray (OR) having three inputs and three outputs are considered for the design of multivariable PID controller. Optimal centralized PID controller is designed by minimizing IAE for servo response with unit step change. Simulations are carried out using SIMULINK-MATLAB software. The statistical performances of the designed controllers such as best, mean, standard deviations of IAE and average functional evaluations for 20 independent trials. For the purpose of comparison, recent version of real coded Genetic Algorithm (RGA) with simulated binary crossover (SBX) and conventional BLT method are used. In order to validate the performance of optimal PID controller for robustness against load disturbance rejection, load regulation experiment with step load disturbance is conducted. Also, to determine the performance of optimal PID controller for robustness against model uncertainty, servo and load response with +20% variations in gains and dead times is conducted. Simulation results reveal that for both OR and WB systems, CMAES designed centralized PID controller is better than other methods and also it is more robust against model uncertainty and load disturbance.Expert Syst. Appl. 01/2010; 37:5775-5781.
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ABSTRACT: This paper discusses the application of the covariance matrix adapted evolution strategy (CMAES) technique to the design of the mixed H2/H ∞ PID controller. The optimal robust PID controller is designed by minimizing the weighted sum of integral squared error (ISE) and balanced robust performance criterion involving robust stability and disturbance attenuation performance subjected to robust stability and disturbance attenuation constraints. In CMAES algorithm, these constraints are effectively handled by penalty parameter-less scheme. In order to test the performance of CMAES algorithm, MIMO distillation column model is considered. For the purpose of comparison, reported intelligent genetic algorithm (IGA) method is used. The statistical performances of combined ISE and balanced robust performance criterion in ten independent simulation runs show that a performance of CMAES is better than IGA method. Robustness test conducted on the system also shows that the robust performance of CMAES designed controller is better than IGA based controller under model uncertainty and external disturbances. KeywordsPID-CMAES-MIMO system-Robustness12/2010: pages 171-181;