Browsing by Author "Romanenko, Andrey"
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- An improved multi-threaded implementation of the MCSFilter optimization algorithmPublication . Monteiro, Luis; Rufino, José; Romanenko, Andrey; Fernandes, Florbela P.The Multistart Coordinate Search Filter (MCSFilter) is an optimization method suitable to find all minimizers of a non convex problem, with any type of constraints. When used in industrial contexts, execution time may be critical, in order to keep production processes within safe and expected bounds. One way to increase performance is through parallelization. In this work, a second parallel version of the MCSFilter method is presented, aiming at faster execution times than a previous parallel implementation. The new solver was tested with a set of fourteen problems, with different characteristics and behavior. The results obtained represent an improvement of the execution times over all previous MCSFilter implementations (sequential and parallel). They also allowed to identify bottlenecks to be lifted in future parallel versions.
- An improved multi-threaded implementation of the MCSFilter optimization algorithmPublication . Monteiro, Luís; Rufino, José; Romanenko, Andrey; Fernandes, Florbela P.The Multistart Coordinate Search Filter (MCSFilter) is an optimization method suitable to find all minimizers of a non convex problem, with any type of constraints. When used in industrial contexts, execution time may be critical, in order to keep production processes within safe and expected bounds. One way to increase performance is through parallelization. In this work, a second parallel version of the MCSFilter method is presented, aiming at faster execution times than a previous parallel implementation. The new solver was tested with a set of fourteen problems, with different characteristics and behavior. The results obtained represent an improvement of the execution times over all previous MCSFilter implementations (sequential and parallel). They also allowed to identify bottlenecks to be lifted in future parallel versions.
- Application of MCSFilter to estimate stiction control valve parametersPublication . Amador, Andreia; Fernandes, Florbela P.; Santos, Lino O.; Romanenko, AndreyThe mitigation of the stiction phenomena in control valves is of paramount importance for efficient industrial plant operation. Mathematical models of sticky valves are typically discontinuous and highly nonlinear. A derivative-free optimization method is applied in the context of parameter estimation in order to determine the stiction parameters of a control valve. The method successfully determines the correct parameter set and compares favorably with a previous case study of this problem that used smooth function.
- Application of mixed integer nonlinear programming for system identificationPublication . Fernandes, Natércia C.P.; Fernandes, Florbela P.; Romanenko, AndreyThis work describes a method of deadtime approximation in dynamic systems, particularly in the context of nonlinear model predictive control based on mechanistic models where the differentiability of the equations must be ensured. The resulting system identification system is solved using the BBMCSFilter (Branch and Bound based on a Multistart Coordinate Search Filter) global optimization algorithm to determine the order and the parameters of the resulting model, taking into account not only the model-plant mismatch but also the model complexity and the resulting computation time. The application of the method is illustrated with a simulated example of a chemical process unit. © 2020 American Institute of Physics Inc.. All rights reserved.
- MCSFilter performance: a comparison studyPublication . Monteiro, Luís; Rufino, José; Romanenko, Andrey; Fernandes, Florbela P.
- MCSFilter performance: a comparison studyPublication . Luis, Monteiro; Rufino, José; Romanenko, Andrey; Fernandes, Florbela P.Optimization plays an important role in an industrial context, generating considerable savings [1,2]. There are several optimization algorithms available. This work focuses on the MCSFilter, a multilocal optimization method able to obtain local and global minimizers — a multistart strategy coupled with a local coordinate search filter to deal with all the constraints [3,4,5].
- Parameter estimation of a pulp digester model with derivative-free optimization strategiesPublication . Seiça, J.C.; Romanenko, Andrey; Fernandes, Florbela P.; Santos, Lino O.; Fernandes, Natércia C.P.The work concerns the parameter estimation in the context of the mechanistic modelling of a pulp digester. The problem is cast as a box bounded nonlinear global optimization problem in order to minimize the mismatch between the model outputs with the experimental data observed at a real pulp and paper plant. MCSFilter and Simulated Annealing global optimization methods were used to solve the optimization problem. While the former took longer to converge to the global minimum, the latter terminated faster at a significantly higher value of the objective function and, thus, failed to find the global solution.
- Parameter estimation of the kinetic α -pinene isomerization model using the MCSfilter algorithmPublication . Amador, Andreia; Fernandes, Florbela P.; Santos, Lino O.; Romanenko, Andrey; Rocha, Ana Maria A.C.This paper aims to illustrate the application of a derivative- free multistart algorithm with coordinate search filter, designated as the MCSFilter algorithm. The problem used in this study is the parameter estimation problem of the kinetic α-pinene isomerization model. This is a well known nonlinear optimization problem (NLP) that has been investigated as a case study for performance testing of most derivative based methods proposed in the literature. Since the MCSFilter algorithm features a stochastic component, it was run ten times to solve the NLP problem. The optimization problem was successfully solved in all the runs and the optimal solution demonstrates that in all runs the MCSFilter provides a good quality solution.
- PID controllers tuning with MCSFilterPublication . Romanenko, Andrey; Fernandes, Florbela P.; Fernandes, Natércia C.P.This work concerns the tuning of industrial controllers through the use of the Multistart Coordinate Search Filter algorithm. The task is laid as a bounded nonlinear global optimization problem aiming at achieving the best possible performance of the control loops at the lowest possible wearing of the costly valves. Moreover, the tuning was successfully carried out both with and without taking into consideration the existing interactions between different loops.