Associate Professor of the Department of Electrical Engineering, Faculty of Engineering and Sciences, University of La Frontera, Temuco - Chile (since 1987). Member of the IEEE and Professor of the IEEE-UFRO Student Branch (since 1995). Member of the Ibero-American Project Engineering Network - RIIPRO (since 2010). My areas of interest are Modeling of Industrial Processes, Analysis and Synthesis of Control Systems, High Power Electric Drives, Energy Efficiencies and Renewable Energies.
This paper presents the results of a recent research that aimed to propose the Pragmatic Dimensio... more This paper presents the results of a recent research that aimed to propose the Pragmatic Dimension's object on the Conceptual Model of Semantic Differential proposed by Osgood, which is a type of a rating scale designed to measure the connotative meaning of concepts that is used to derive the attitude towards the given object for user. The measurement of meaning is addressed in two ways: by developing a theoretical-conceptual and development through the data. The first focus involves an approach to the problem of the measurement of meaning, was offered a theoretical-conceptual framework which allowed us to establish new categories in the Semantic Space for the collecting and interpretation on the user´s expectations, from a pragmatic perspective of the object. The second option, that aimed a methodological approach, is developed a focalization more empirical in the theme study that to focussing on collecting and analyzing data, was developed a pilot study in which was observed h...
This paper presents the results of a recent research that aimed to propose the Pragmatic Dimensio... more This paper presents the results of a recent research that aimed to propose the Pragmatic Dimension's object on the Conceptual Model of Semantic Differential proposed by Osgood, which is a type of a rating scale designed to measure the connotative meaning of concepts that is used to derive the attitude towards the given object for user. The measurement of meaning is addressed in two ways: by developing a theoretical-conceptual and development through the data. The first focus involves an approach to the problem of the measurement of meaning, was offered a theoretical-conceptual framework which allowed us to establish new categories in the Semantic Space for the collecting and interpretation on the user´s expectations, from a pragmatic perspective of the object. The second option, that aimed a methodological approach, is developed a focalization more empirical in the theme study that to focussing on collecting and analyzing data, was developed a pilot study in which was observed h...
Aging population and the difficulties involved in the social protection systems appears to be a f... more Aging population and the difficulties involved in the social protection systems appears to be a feature of all developed countries. Socio-demographic and economic processes (aging, active population reduction, macroeconomic problems, mainly in countries in transition), which will increase in the coming decades transform the problem of social protcţiei older people and in particular the problem of effective management of pension a fundamental challenge for both developed countries and those in transition. To note is that at the moment, the pension system is not completely self-sustaining, the state budget transferring about 2.5 percent of PIB It was analyzed by the experts in that area if the percentage would rise about three percent, serious problems might occur equilibrium (the effects will be felt in the economy, increased taxation, reduced investment, and so on), and if four percent to reach equilibrium would be lost. Now transfers provides an optimal degree of adequacy of pensio...
2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017
The aim of this work is to study the bending effect of the tower of a variable speed wind turbine... more The aim of this work is to study the bending effect of the tower of a variable speed wind turbine system on its production of electrical energy and how this production is related to the structural fatigue of the tower. The research is built using a simulator based on Matlab / Simulink software. The model of variable speed energy conversion system, has an aerodynamic stage described according to unsteady blade element (BEM) theory, an electromechanical stage with a double fed induction generator (DFIG) and the structural stage described by a cantilever beam with the first oscillation mode, considering that the DFIG uses stator voltage orientation control (SVOC) and PID controller. The SCEVV is a Hammerstein model, linear time variant, with two feedback loops towards the aerodynamic stage, one is the velocity ratio at the tip of the blade and another is the angle of the tower flexion. The feedback of the flexion angle generates variations in the pitch angle of the blades and this deve...
In this paper a Model Predictive Control (MPC) was applied to the flux and torque control of a Sy... more In this paper a Model Predictive Control (MPC) was applied to the flux and torque control of a Synchronous Reluctance Motor, SynRM. The behavior of the controller was analyzed based on model's simulations performed in Matlab/Simulink Software. From the results, it was verified that the controller has good performance. The SynRM can reach the speed reference value controlling simultaneously flux and torque.
Biotechnological processes are very complex systems for modeling, due to the presence of live mic... more Biotechnological processes are very complex systems for modeling, due to the presence of live microorganisms, nonlinear behavior and time-variant features. Many parameters of the process are uncertain and the industrial operating conditions are determined empirically for them. This paper presents a robust dynamic simulator in Matlab/Simulink environment from the work of Scaglia and the study of experimental data for analysis purposes of the fermentation process. The problem with these processes is given by the difficulty of obtaining data online. In this regard, it should be noted that the dominant state variable, given by the substrate concentration in the medium, is very difficult to measure, due to the strong parametric uncertainty and the presence of significant nonlinearities. In addition to this, the measuring of amount of bacteria is typically performed through a culture procedure that requires a significant amount of time. Thus, a state observer is developed from experimental data and the Scaglias Model, using neural networks, in order to facilitate the estimation of state variables values. This produced satisfactory results for a network with five neurons. The observer could, therefore, estimate in a short time: the amount of substrate, bacteria, CO2 and ethanol in the sample.
The biological treatment of industrial waste is a priority theme for the sustainable development ... more The biological treatment of industrial waste is a priority theme for the sustainable development of any society. In recent years, there has been a significant increase in the study of the efficiency of this process. This study aims to control the dissolved oxygen concentration through the agitator to degrade organic matter and total ammonia nitrogen within the established hydraulic residence time with less control effort. For that, two control schemes ware designed in Matlab, a conventional PI and a PI with parameters optimized regarding some conditions. In both cases, de degradation was succeed, but the second one achieve a lower control effort, 200 rpm less than the PI conventional and an early stabilization of the concentration of dissolved oxygen, about ten hours less.
Resumen El trabajo presenta el diseño de un Controlador Predictivo No Lineal aplicado a un Horno ... more Resumen El trabajo presenta el diseño de un Controlador Predictivo No Lineal aplicado a un Horno Rotatorio para la producción eficiente de carbón activado incorporando un modelo ANFIS, la cual se define como un Modelo Híbrido Neuro-Difuso, donde las reglas se aplican siguiendo una estructura de red tipo neuronal, que se interpreta como una red neuronal con parámetros difusos o como un sistema difuso con funcionamiento distribuidos. El proceso no lineal justifica la utilización de este tipo de controlador, dado el número de variables involucradas y las situaciones extremas a la que será sometida la planta, en donde se prevé saldrá a reducir la dinámica no lineal. El carbón activado, es un gran adsorbente y uno de los productos más usados en diversos campos de aplicación, que abarcan desde la medicina hasta la industria alimenticia. La metodología está en base al simulador de la planta realizada en Ortiz (2005), que corresponde al proceso estudiado; el modelo de predicción utilizó ANF...
The importance of standing position for humans is related to the benefits associated with it. The... more The importance of standing position for humans is related to the benefits associated with it. The lack of control in this position has required to design a mechanical systems that allow it, in addition, the incorporation a displacement controlled system by the user, have allowed to disabled people perform tasks of daily living, and improve their self-esteem. This paper develops an evaluation of a prototype of a mobile stander for child, as the key for continuous improvement and quality of the product.
ABSTRACT The four-stage evaporator is the core of the process in the manufacture of concentrated ... more ABSTRACT The four-stage evaporator is the core of the process in the manufacture of concentrated grape juice. The dynamic features of this process are very complex due to inputs and outputs constraints, time delays, loop interactions and the persistent unmeasured disturbances that affect it. Therefore, this kind of process equires a robust control in order to assure a stable operation taking into account the changes in the organoleptic properties of the raw material and, to guarantee the quality of the concentrated product. The mathematical model of the evaporator is obtained by application of the mass and energy balances to each effect. A linear model is identified from a nonlinear model. This linear model is used for control design employing an LTR procedure. Simulation studies show that the proposed control design approach is useful and may prove effective in evaporator control, therefore the performance of the two designs for set point tracking and unmeasured rejection are compared.
This paper presents a dynamic simulation system (DSS) and a simulation study of a pilot scale rot... more This paper presents a dynamic simulation system (DSS) and a simulation study of a pilot scale rotary kiln for activated carbon manufacture. DSS has been developed by using the Simulink–Matlab framework, based on a dynamic mathematical model. The model consists of a set of nonlinear partial differential equations, and represents the mass and energy balances in the kiln. The space
La preocupante situación medioambiental a nivel global y la constante innovación han permitido el... more La preocupante situación medioambiental a nivel global y la constante innovación han permitido el mejoramiento de la eficiencia energética de los sistemas eólicos debido al avance en el tamaño de los generadores y al desarrollo de la electrónica de potencia para su extracción. ...
This paper presents the results of a recent research that aimed to propose the Pragmatic Dimensio... more This paper presents the results of a recent research that aimed to propose the Pragmatic Dimension's object on the Conceptual Model of Semantic Differential proposed by Osgood, which is a type of a rating scale designed to measure the connotative meaning of concepts that is used to derive the attitude towards the given object for user. The measurement of meaning is addressed in two ways: by developing a theoretical-conceptual and development through the data. The first focus involves an approach to the problem of the measurement of meaning, was offered a theoretical-conceptual framework which allowed us to establish new categories in the Semantic Space for the collecting and interpretation on the user´s expectations, from a pragmatic perspective of the object. The second option, that aimed a methodological approach, is developed a focalization more empirical in the theme study that to focussing on collecting and analyzing data, was developed a pilot study in which was observed h...
This paper presents the results of a recent research that aimed to propose the Pragmatic Dimensio... more This paper presents the results of a recent research that aimed to propose the Pragmatic Dimension's object on the Conceptual Model of Semantic Differential proposed by Osgood, which is a type of a rating scale designed to measure the connotative meaning of concepts that is used to derive the attitude towards the given object for user. The measurement of meaning is addressed in two ways: by developing a theoretical-conceptual and development through the data. The first focus involves an approach to the problem of the measurement of meaning, was offered a theoretical-conceptual framework which allowed us to establish new categories in the Semantic Space for the collecting and interpretation on the user´s expectations, from a pragmatic perspective of the object. The second option, that aimed a methodological approach, is developed a focalization more empirical in the theme study that to focussing on collecting and analyzing data, was developed a pilot study in which was observed h...
Aging population and the difficulties involved in the social protection systems appears to be a f... more Aging population and the difficulties involved in the social protection systems appears to be a feature of all developed countries. Socio-demographic and economic processes (aging, active population reduction, macroeconomic problems, mainly in countries in transition), which will increase in the coming decades transform the problem of social protcţiei older people and in particular the problem of effective management of pension a fundamental challenge for both developed countries and those in transition. To note is that at the moment, the pension system is not completely self-sustaining, the state budget transferring about 2.5 percent of PIB It was analyzed by the experts in that area if the percentage would rise about three percent, serious problems might occur equilibrium (the effects will be felt in the economy, increased taxation, reduced investment, and so on), and if four percent to reach equilibrium would be lost. Now transfers provides an optimal degree of adequacy of pensio...
2017 CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON), 2017
The aim of this work is to study the bending effect of the tower of a variable speed wind turbine... more The aim of this work is to study the bending effect of the tower of a variable speed wind turbine system on its production of electrical energy and how this production is related to the structural fatigue of the tower. The research is built using a simulator based on Matlab / Simulink software. The model of variable speed energy conversion system, has an aerodynamic stage described according to unsteady blade element (BEM) theory, an electromechanical stage with a double fed induction generator (DFIG) and the structural stage described by a cantilever beam with the first oscillation mode, considering that the DFIG uses stator voltage orientation control (SVOC) and PID controller. The SCEVV is a Hammerstein model, linear time variant, with two feedback loops towards the aerodynamic stage, one is the velocity ratio at the tip of the blade and another is the angle of the tower flexion. The feedback of the flexion angle generates variations in the pitch angle of the blades and this deve...
In this paper a Model Predictive Control (MPC) was applied to the flux and torque control of a Sy... more In this paper a Model Predictive Control (MPC) was applied to the flux and torque control of a Synchronous Reluctance Motor, SynRM. The behavior of the controller was analyzed based on model's simulations performed in Matlab/Simulink Software. From the results, it was verified that the controller has good performance. The SynRM can reach the speed reference value controlling simultaneously flux and torque.
Biotechnological processes are very complex systems for modeling, due to the presence of live mic... more Biotechnological processes are very complex systems for modeling, due to the presence of live microorganisms, nonlinear behavior and time-variant features. Many parameters of the process are uncertain and the industrial operating conditions are determined empirically for them. This paper presents a robust dynamic simulator in Matlab/Simulink environment from the work of Scaglia and the study of experimental data for analysis purposes of the fermentation process. The problem with these processes is given by the difficulty of obtaining data online. In this regard, it should be noted that the dominant state variable, given by the substrate concentration in the medium, is very difficult to measure, due to the strong parametric uncertainty and the presence of significant nonlinearities. In addition to this, the measuring of amount of bacteria is typically performed through a culture procedure that requires a significant amount of time. Thus, a state observer is developed from experimental data and the Scaglias Model, using neural networks, in order to facilitate the estimation of state variables values. This produced satisfactory results for a network with five neurons. The observer could, therefore, estimate in a short time: the amount of substrate, bacteria, CO2 and ethanol in the sample.
The biological treatment of industrial waste is a priority theme for the sustainable development ... more The biological treatment of industrial waste is a priority theme for the sustainable development of any society. In recent years, there has been a significant increase in the study of the efficiency of this process. This study aims to control the dissolved oxygen concentration through the agitator to degrade organic matter and total ammonia nitrogen within the established hydraulic residence time with less control effort. For that, two control schemes ware designed in Matlab, a conventional PI and a PI with parameters optimized regarding some conditions. In both cases, de degradation was succeed, but the second one achieve a lower control effort, 200 rpm less than the PI conventional and an early stabilization of the concentration of dissolved oxygen, about ten hours less.
Resumen El trabajo presenta el diseño de un Controlador Predictivo No Lineal aplicado a un Horno ... more Resumen El trabajo presenta el diseño de un Controlador Predictivo No Lineal aplicado a un Horno Rotatorio para la producción eficiente de carbón activado incorporando un modelo ANFIS, la cual se define como un Modelo Híbrido Neuro-Difuso, donde las reglas se aplican siguiendo una estructura de red tipo neuronal, que se interpreta como una red neuronal con parámetros difusos o como un sistema difuso con funcionamiento distribuidos. El proceso no lineal justifica la utilización de este tipo de controlador, dado el número de variables involucradas y las situaciones extremas a la que será sometida la planta, en donde se prevé saldrá a reducir la dinámica no lineal. El carbón activado, es un gran adsorbente y uno de los productos más usados en diversos campos de aplicación, que abarcan desde la medicina hasta la industria alimenticia. La metodología está en base al simulador de la planta realizada en Ortiz (2005), que corresponde al proceso estudiado; el modelo de predicción utilizó ANF...
The importance of standing position for humans is related to the benefits associated with it. The... more The importance of standing position for humans is related to the benefits associated with it. The lack of control in this position has required to design a mechanical systems that allow it, in addition, the incorporation a displacement controlled system by the user, have allowed to disabled people perform tasks of daily living, and improve their self-esteem. This paper develops an evaluation of a prototype of a mobile stander for child, as the key for continuous improvement and quality of the product.
ABSTRACT The four-stage evaporator is the core of the process in the manufacture of concentrated ... more ABSTRACT The four-stage evaporator is the core of the process in the manufacture of concentrated grape juice. The dynamic features of this process are very complex due to inputs and outputs constraints, time delays, loop interactions and the persistent unmeasured disturbances that affect it. Therefore, this kind of process equires a robust control in order to assure a stable operation taking into account the changes in the organoleptic properties of the raw material and, to guarantee the quality of the concentrated product. The mathematical model of the evaporator is obtained by application of the mass and energy balances to each effect. A linear model is identified from a nonlinear model. This linear model is used for control design employing an LTR procedure. Simulation studies show that the proposed control design approach is useful and may prove effective in evaporator control, therefore the performance of the two designs for set point tracking and unmeasured rejection are compared.
This paper presents a dynamic simulation system (DSS) and a simulation study of a pilot scale rot... more This paper presents a dynamic simulation system (DSS) and a simulation study of a pilot scale rotary kiln for activated carbon manufacture. DSS has been developed by using the Simulink–Matlab framework, based on a dynamic mathematical model. The model consists of a set of nonlinear partial differential equations, and represents the mass and energy balances in the kiln. The space
La preocupante situación medioambiental a nivel global y la constante innovación han permitido el... more La preocupante situación medioambiental a nivel global y la constante innovación han permitido el mejoramiento de la eficiencia energética de los sistemas eólicos debido al avance en el tamaño de los generadores y al desarrollo de la electrónica de potencia para su extracción. ...
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Papers by Nelson Aros