@article {237, title = {Growth rate maximization in fed-batch processes using high order sliding controllers and observers based on cell density measurement}, journal = {Journal of Process Control}, volume = {68}, year = {2018}, month = {04/2018}, pages = {23 - 33}, abstract = {

A novel extremum seeking scheme is proposed for the optimization of the specific growth rate in fed-batch processes with substrate inhibited kinetics. The proposed controller is based on a high order sliding mode algorithm, which uses the gradient of the specific growth rate as switching coordinate. A gradient estimation is obtained through a high order sliding mode observer. Both the control and gradient estimation algorithms are finite-time stable. The stability of the controller is analysed using Lyapunov functions for both the unperturbed and perturbed cases and guidelines for the algorithm tuning are provided. The controller and observer algorithms are numerically assessed and simulation results are obtained for a set of different scenarios.

}, keywords = {extremum seeking, Fed-batch, Gradient, Sliding mode}, issn = {0959-1524}, doi = {https://doi.org/10.1016/j.jprocont.2018.04.003}, url = {https://www.sciencedirect.com/science/article/pii/S0959152418300659}, author = {Jamilis, Mart{\'\i}n and Garelli, Fabricio and De Battista, Hern{\'a}n} } @article {157, title = {Modeling and estimation of production rate for the production phase of non-growth associated high cell density processes}, journal = {Bioprocess and Biosystems Engineering}, volume = {38}, year = {2015}, pages = {1903-1914}, abstract = {This paper addresses the estimation of the specific production rate of intracellular products and the modeling of the bioreactor volume dynamics in high cell density fed-batch reactors. In particular, a new model for the bioreactor volume is proposed, suitable to be used in high cell density cultures where large amounts of intracellular products are stored. Based on the proposed volume model, two forms of a high order sliding mode observer are proposed. Each form corresponds to the cases with residual biomass concentration or volume measurement respectively. The observers achieve finite time convergence and robustness to process uncertainties as the kinetic model is not required. Stability proofs for the proposed observer are given. The observer algorithm is assessed numerically and experimentally.}, keywords = {Bioplastics, Estimation, high cell density, Observer, PHB, Sliding mode, Software sensor, volume model}, doi = {10.1007/s00449-015-1430-7}, author = {Jamilis, Mart{\'\i}n and Garelli, Fabricio and Mozumder, MSI and Casta{\~n}eda, Teresita and De Battista, Hern{\'a}n} } @article {7, title = {Integrated sliding-mode algorithms in robot tracking applications}, journal = {Robotics and Computer-Integrated Manufacturing}, volume = {29}, year = {2013}, pages = {53 - 62}, abstract = {

An integrated solution based on sliding mode ideas is proposed for robotic trajectory tracking. The proposal includes three sliding-mode algorithms for speed auto-regulation, path conditioning and redundancy resolution in order to fulfill velocity, workspace and C-space constraints, respectively. The proposed method only requires a few program lines and simplifies the robot user interface since it directly deals with the fulfillment of the constraints to find a feasible solution for the robot trajectory tracking in a short computation time. The proposed approach is evaluated in simulation on the freely accessible 6R robot model PUMA-560, for which the main features of the method are illustrated.

}, keywords = {Sliding mode}, issn = {0736-5845}, doi = {10.1016/j.rcim.2012.07.007}, url = {http://www.sciencedirect.com/science/article/pii/S0736584512000919}, author = {Gracia, Luis and Garelli, Fabricio and Sala, Antonio} } @article {15, title = {A supervisory loop approach to fulfill workspace constraints in redundant robots}, journal = {Robotics and Autonomous Systems}, volume = {60}, year = {2012}, pages = {1 - 15}, abstract = {

An approach based on geometric invariance and sliding mode ideas is proposed for redundancy resolution in robotic systems to fulfill configuration and workspace constraints caused by robot mechanical limits, collision avoidance, industrial security, etc. Some interesting features of the proposal are that: (1)\ it can be interpreted as a limit case of the classical potential field-based approach for collision avoidance which requires using variable structure control concepts, (2)\ it allows reaching the limit surface of the constraints smoothly, depending on a free design parameter, and (3)\ it can be easily added as a supervisory block to pre-existing redundancy resolution schemes. The algorithm is evaluated in simulation on a 6R planar robot and on the freely accessible 6R robot model PUMA-560, for which the main features of the method are illustrated.

}, keywords = {Sliding mode}, issn = {0921-8890}, doi = {10.1016/j.robot.2011.07.008}, url = {http://www.sciencedirect.com/science/article/pii/S0921889011001308}, author = {Gracia, Luis and Sala, Antonio and Garelli, Fabricio} } @article {92, title = {A simple robust controller for power maximization of a variable-speed wind turbine}, journal = {International Journal of Energy Research}, volume = {34}, year = {2010}, pages = {924{\textendash}932}, abstract = {

This paper presents a high-order sliding mode control strategy that aims to optimize the power conversion efficiency of a wind energy conversion system within the partial load zone of operation. The main challenges of this control problem are related to the random variations of the wind speed, the nonlinear nature of the whole system, usual model uncertainties and external disturbances. For all these reasons, the robustness, simplicity and low computational burden of the proposed super-twisting algorithm result very attractive in this context. Simulation results that show the achievement of the desired characteristics are provided. Copyright {\^A}{\textcopyright} 2009 John Wiley \& Sons, Ltd.

}, keywords = {efficiency optimization, Robust control, Sliding mode, Wind energy}, issn = {1099-114X}, doi = {10.1002/er.1613}, url = {http://dx.doi.org/10.1002/er.1613}, author = {Evangelista, Carolina A. and Puleston, Pablo F. and Valenciaga, Fernando} } @article {73, title = {Harmonic series compensators in power systems: their control via sliding mode}, journal = {Control Systems Technology, IEEE Transactions on}, volume = {8}, year = {2000}, month = {Nov}, pages = {939-947}, abstract = {

This paper deals with harmonic current compensation in power systems using shunt passive and series active filters. It is shown how constraints of the active filters can notoriously degrade the performance of the compensating system. The use of variable structure system theory is suggested for analysis and design of series active filters. Sliding mode control strategies to improve harmonic rejection are proposed, and active filters with different switching-ripple filters are considered. These control strategies provide robustness to active filter modeling errors and external disturbances

}, keywords = {active filters, compensation, Control systems, Degradation, harmonic series compensation, Power harmonic filters, Power system analysis computing, power system control, power system harmonics, power systems, Robustness, Sliding mode, Sliding mode control, variable structure system, variable structure systems}, issn = {1063-6536}, doi = {10.1109/87.880597}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=880597}, author = {De Battista, Hern{\'a}n and Mantz, Ricardo J.} }