@article {50, title = {Safety Auxiliary Feedback Element for the Artificial Pancreas in Type 1 Diabetes}, journal = {Biomedical Engineering, IEEE Transactions on}, volume = {60}, year = {2013}, month = {Aug}, pages = {2113-2122}, abstract = {

The artificial pancreas aims at the automatic delivery of insulin for glycemic control in patients with type 1 diabetes, i.e., closed-loop glucose control. One of the challenges of the artificial pancreas is to avoid controller overreaction leading to hypoglycemia, especially in the late postprandial period. In this study, an original proposal based on sliding mode reference conditioning ideas is presented as a way to reduce hypoglycemia events induced by a closed-loop glucose controller. The method is inspired in the intuitive advantages of two-step constrained control algorithms. It acts on the glucose reference sent to the main controller shaping it so as to avoid violating given constraints on the insulin-on-board. Some distinctive features of the proposed strategy are that 1) it provides a safety layer which can be adjusted according to medical criteria; 2) it can be added to closed-loop controllers of any nature; 3) it is robust against sensor failures and overestimated prandial insulin doses; and 4) it can handle nonlinear models. The method is evaluated in silico with the ten adult patients available in the FDA-accepted UVA simulator.

}, keywords = {Absorption, Artificial, artificial organs, Artificial pancreas, Biological, Blood Glucose Self-Monitoring, closed loop systems, closed-loop glucose control, Computer Simulation, Computer-Assisted, Diabetes, Diabetes Mellitus, diseases, drug delivery systems, Drug Therapy, drugs, Equipment Safety, FDA-accepted UVA simulator, feedback, glucose control, glycemic control, Humans, hypoglycemia, insulin, insulin-on-board, medical control systems, Models, Pancreas, Physiological, postprandial period, Proposals, reference conditioning, Robustness, safety, safety auxiliary feedback element, sliding mode (SM), sliding mode reference conditioning, Sugar, two-step constrained control algorithms, Type 1, type 1 diabetes}, issn = {0018-9294}, doi = {10.1109/TBME.2013.2247602}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=6463437}, author = {Revert, Ana and Garelli, Fabricio and Pic{\'o}, Jes{\'u}s and De Battista, Hern{\'a}n and Rossetti, Paolo and Veh{\'\i}, Josep and Bondia, Jorge} } @conference {91, title = {Variable gains super-twisting control for wind energy conversion optimization}, booktitle = {Variable Structure Systems (VSS), 2010 11th International Workshop on}, year = {2010}, month = {June}, abstract = {

An adaptive second order sliding mode control strategy is explored in this work, to maximize the energy extracted from the wind in a wind energy conversion system (WECS). It is required to such strategy to deal with the nonlinear nature of the WECS, the randomness of the wind speed, model uncertainties and external disturbances, and also with the need to reduce mechanical loads. The special features of this adaptive technique together with the robustness, relative simplicity and other desirable inherent characteristics of the super-twisting algorithm make the proposed controller an attractive solution. The suitability of the proposed strategy is proved by extensive computer aided simulations employing a comprehensive model of the system.

}, keywords = {adaptive control, adaptive second order sliding mode control, Computational modeling, computer aided simulation, Computer Simulation, control system synthesis, Gain, Lyapunov based controller design, Lyapunov methods, nonlinear systems, optimisation, Programmable control, Robust control, Sliding mode control, Uncertainty, variable gain super twisting control, variable structure systems, Wind energy, wind energy conversion optimization, wind power, Wind speed}, doi = {10.1109/VSS.2010.5544713}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=5544713}, author = {Evangelista, Carolina A. and Puleston, Pablo F. and Valenciaga, Fernando and D{\textquoteright}ávila, A.} } @article {108, title = {Power control of a solar/wind generation system without wind measurement: a passivity/sliding mode approach}, journal = {Energy Conversion, IEEE Transactions on}, volume = {18}, year = {2003}, month = {Dec}, pages = {501-507}, abstract = {

This paper deals with the control of the output power of a solar/wind stand-alone system. The control system regulates the generation of the wind subsystem in order to satisfy, jointly with the photovoltaic generation subsystem, the load and battery charge power demand. The controller is designed using a theoretical framework that unifies passivity and sliding mode techniques. The resultant control law does not need wind measurement and only relies on rotational speed and current measurements. An analysis of the acceleration estimate error is carried out and a countermeasure to compensate its effects is proposed. Finally, the performance of the controller is assessed through computer simulation, using a comprehensive nonlinear model of the plant.

}, keywords = {acceleration estimate error, angular velocity measurement, Battery charge measurement, Computer Simulation, control law, Control systems, controller design, Current measurement, current measurements, effects compensation, electric current measurement, hybrid power systems, nonlinear model, output power control, passivity/sliding mode approach, photovoltaic generation subsystem, photovoltaic power systems, Power control, power demand, Power generation, power generation control, Power measurement, rotational speed measurements, Sliding mode control, sliding mode techniques, Solar power generation, solar/wind generation system, stand-alone system, variable structure systems, Wind energy generation, wind generation subsystem control, Wind power generation, wind turbines}, issn = {0885-8969}, doi = {10.1109/TEC.2003.816602}, url = {http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1247775}, author = {Valenciaga, Fernando and Puleston, Pablo F. and Battaiotto, Pedro E.} }