The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Fabrício Nogueira - One of the best experts on this subject based on the ideXlab platform.
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Analysis and experimental application of a dead-time compensator for input saturated processes with output time-varying delays
IET Control Theory and Applications, 2021Co-Authors: Thiago Lima, Sophie Tarbouriech, Frédéric Gouaisbaut, Magno Almeida Filho, Pedro García, Bismark Torrico, Fabrício NogueiraAbstract:Dead-time compensators (DTCs) are a family of classical controllers derived from the Smith Predictor (SP). Their main characteristic is that they explicitly employ the model of the open-loop process to feedback a predicted value of the non-delayed system, thus obtaining \textit{compensation} of the delay. Such a perfect compensation is not achievable in the case of time-varying delays. In this paper, we address stability analysis of a DTC structure in this situation, in addition to considering saturating actuators and disturbances of limited energy. Specific challenges related to the DTC closed loop are taken into account in the developed theoretical conditions, which are expressed in terms of linear matrix inequalities (LMIs) by using an adequate Lyapunov-Krasovskii functional (LKF) and generalized sector conditions. Furthermore, a new approach for the definition of the set of initial conditions in an augmented space in conjunction with the LKF is presented. Besides theoretical innovations, practical discussion about the relation between the tuning of DTC controllers and robustness for this class of systems is presented through numerical examples. An experimental application on a Neonatal Incubator prototype is carried out to emphasize the effectiveness of the results.
Thiago Lima - One of the best experts on this subject based on the ideXlab platform.
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Analysis and experimental application of a dead-time compensator for input saturated processes with output time-varying delays
IET Control Theory and Applications, 2021Co-Authors: Thiago Lima, Sophie Tarbouriech, Frédéric Gouaisbaut, Magno Almeida Filho, Pedro García, Bismark Torrico, Fabrício NogueiraAbstract:Dead-time compensators (DTCs) are a family of classical controllers derived from the Smith Predictor (SP). Their main characteristic is that they explicitly employ the model of the open-loop process to feedback a predicted value of the non-delayed system, thus obtaining \textit{compensation} of the delay. Such a perfect compensation is not achievable in the case of time-varying delays. In this paper, we address stability analysis of a DTC structure in this situation, in addition to considering saturating actuators and disturbances of limited energy. Specific challenges related to the DTC closed loop are taken into account in the developed theoretical conditions, which are expressed in terms of linear matrix inequalities (LMIs) by using an adequate Lyapunov-Krasovskii functional (LKF) and generalized sector conditions. Furthermore, a new approach for the definition of the set of initial conditions in an augmented space in conjunction with the LKF is presented. Besides theoretical innovations, practical discussion about the relation between the tuning of DTC controllers and robustness for this class of systems is presented through numerical examples. An experimental application on a Neonatal Incubator prototype is carried out to emphasize the effectiveness of the results.
M M Shepley - One of the best experts on this subject based on the ideXlab platform.
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The design of Neonatal Incubators: a systems-oriented, human-centered approach
Journal of Perinatology, 2013Co-Authors: T K Ferris, M M ShepleyAbstract:Objective: This report describes a multidisciplinary design project conducted in an academic setting reflecting a systems-oriented, human-centered philosophy in the design of Neonatal Incubator technologies. Study Design: Graduate students in Architectural Design and Human Factors Engineering courses collaborated in a design effort that focused on supporting the needs of three user groups of Incubator technologies: infant patients, family members and medical personnel. Design teams followed established human-centered design methods that included interacting with representatives from the user groups, analyzing sets of critical tasks and conducting usability studies with existing technologies. Result: An iterative design and evaluation process produced four conceptual designs of Incubators and supporting equipment that better address specific needs of the user groups. Conclusion: This report introduces the human-centered design approach, highlights some of the analysis findings and design solutions, and offers a set of design recommendations for future incubation technologies.
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The design of Neonatal Incubators: a systems-oriented, human-centered approach.
Journal of perinatology : official journal of the California Perinatal Association, 2013Co-Authors: T K Ferris, M M ShepleyAbstract:This report describes a multidisciplinary design project conducted in an academic setting reflecting a systems-oriented, human-centered philosophy in the design of Neonatal Incubator technologies. Graduate students in Architectural Design and Human Factors Engineering courses collaborated in a design effort that focused on supporting the needs of three user groups of Incubator technologies: infant patients, family members and medical personnel. Design teams followed established human-centered design methods that included interacting with representatives from the user groups, analyzing sets of critical tasks and conducting usability studies with existing technologies. An iterative design and evaluation process produced four conceptual designs of Incubators and supporting equipment that better address specific needs of the user groups. This report introduces the human-centered design approach, highlights some of the analysis findings and design solutions, and offers a set of design recommendations for future incubation technologies.
Bismark C Torrico - One of the best experts on this subject based on the ideXlab platform.
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Implementation and test of a new autotuning method for PID controllers of TITO processes
Control Engineering Practice, 2017Co-Authors: Rene D O Pereira, Massimiliano Veronesi, Antonio Visioli, Julio E. Normey-rico, Bismark C TorricoAbstract:Abstract In this paper we present a new closed-loop automatic tuning methodology for decentralised proportional–integral–derivative (PID) controllers applied to two-inputs–two-outputs (TITO) non-singular processes. The main feature of the technique is the estimation of the process parameters by evaluating two closed-loop set-point step responses with two roughly tuned PID controllers already in place. Then, once a process model has been obtained, the PID controllers can be retuned by using any rule available in the literature and suitable for the application. Simulation examples, comparative results with other works and a real application on a Neonatal Incubator prototype are given to illustrate the methodology and to show its effectiveness.
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Optimal control of MIMO dead-time linear systems with dead-time compensation structure
DYNA, 2017Co-Authors: Wilkley Bezerra Correia, Bismark C Torrico, Rene D O PereiraAbstract:State space optimal controllers became popular over the last decades mainly because of its performance and robustness properties, as well as easy extension for multi-variable systems (MIMO). On the other hand, many industrial processes present dominant dead-time which may cause issues related to performance or even stability. Despite of its importance, few works from optimal control may be traced for this matter. In order to deal with dead-time effect one may use dead-time compensation (DTC) structures, mainly applied for single-variable systems (SISO). Within this context, this work proposes to modify a prediction structure recently proposed aiming to combine the best properties of both DTC and optimal control for MIMO linear systems. Simulation results along with the application to an experimental setup of a Neonatal Incubator prototype are presented to highlight the advantages and show the effectiveness of the proposed control strategy, as well as its practical aspect.
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new automatic tuning of multivariable pid controller applied to a Neonatal Incubator
BioMedical Engineering and Informatics, 2015Co-Authors: Rene D O Pereira, Bismark C TorricoAbstract:This work studies an automatic tuning technique of multivariable Proportional-Integral-Derivative (PID) controllers applied to a Neonatal Incubator. The method consists of the identification of a first order plus dead-time (FOPDT) model of a two-input and two-output (TITO) process and the utilization of this model to retune the PID controller. To perform the identification, a sequence of setpoint step changes, one at each input, is applied until the steady-state is reached and the step responses are evaluated by analytic formulae. As a TITO process, the temperature and relative humidity control on a Neonatal Incubator is a proper application for this new method. Experimental results are presented and prove the effectiveness of the method.
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BMEI - New automatic tuning of multivariable PID controller applied to a Neonatal Incubator
2015 8th International Conference on Biomedical Engineering and Informatics (BMEI), 2015Co-Authors: Rene D O Pereira, Bismark C TorricoAbstract:This work studies an automatic tuning technique of multivariable Proportional-Integral-Derivative (PID) controllers applied to a Neonatal Incubator. The method consists of the identification of a first order plus dead-time (FOPDT) model of a two-input and two-output (TITO) process and the utilization of this model to retune the PID controller. To perform the identification, a sequence of setpoint step changes, one at each input, is applied until the steady-state is reached and the step responses are evaluated by analytic formulae. As a TITO process, the temperature and relative humidity control on a Neonatal Incubator is a proper application for this new method. Experimental results are presented and prove the effectiveness of the method.
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Filtered model-based predictive control applied to the temperature and humidity control of a Neonatal Incubator
2010 9th IEEE IAS International Conference on Industry Applications - INDUSCON 2010, 2010Co-Authors: Marcos Uchoa Cavalcante, Bismark C Torrico, O. M. Almeida, Arthur Plínio De Souza Braga, Francisco Lincoln Matos Da Costa FilhoAbstract:This paper proposes a robust multivariable predictive control algorithm that improves the robustness of closed loop systems, even when they have multiple time delays between the inputs and outputs. The desired robustness is achieved by including an appropriate filter on the disturbances model. The proposed algorithm is applied to the control of humidity and temperature of a Neonatal Incubator. Simulation and experimental results show the advantages of the proposed algorithm compared to others proposed in the literature.
Bismark Torrico - One of the best experts on this subject based on the ideXlab platform.
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Analysis and experimental application of a dead-time compensator for input saturated processes with output time-varying delays
IET Control Theory and Applications, 2021Co-Authors: Thiago Lima, Sophie Tarbouriech, Frédéric Gouaisbaut, Magno Almeida Filho, Pedro García, Bismark Torrico, Fabrício NogueiraAbstract:Dead-time compensators (DTCs) are a family of classical controllers derived from the Smith Predictor (SP). Their main characteristic is that they explicitly employ the model of the open-loop process to feedback a predicted value of the non-delayed system, thus obtaining \textit{compensation} of the delay. Such a perfect compensation is not achievable in the case of time-varying delays. In this paper, we address stability analysis of a DTC structure in this situation, in addition to considering saturating actuators and disturbances of limited energy. Specific challenges related to the DTC closed loop are taken into account in the developed theoretical conditions, which are expressed in terms of linear matrix inequalities (LMIs) by using an adequate Lyapunov-Krasovskii functional (LKF) and generalized sector conditions. Furthermore, a new approach for the definition of the set of initial conditions in an augmented space in conjunction with the LKF is presented. Besides theoretical innovations, practical discussion about the relation between the tuning of DTC controllers and robustness for this class of systems is presented through numerical examples. An experimental application on a Neonatal Incubator prototype is carried out to emphasize the effectiveness of the results.
