Papers by RAFAEL SEMINARIO VASQUEZ
Energies
Hydropower plants cover almost 70% of the Colombian electrical demand, were built several decades... more Hydropower plants cover almost 70% of the Colombian electrical demand, were built several decades ago, and present low levels of digitisation compared to other modern power-generation technologies, e.g., wind turbines, solar PV plants, and recently buil hydroelectric plants t. Renovating power plant equipment and investing in modernisation and digitisation can significantly increase the plant flexibility. Those actions will increase a plant’s operational safety and contribute to the solution of environmental and social problems. This work presents the actions followed to extend the lifetime of a 1000 MW hydropower plant operating for more than 40 years. Activities included a residual life status evaluation of generators and component upgrades, among others. The rehabilitation and digitalisation of the generation units allow their integration and remote monitoring so that diagnostic actions can be carried out during a continuous and economically sustainable operation. These activitie...
Revista Environment & Technology, Jun 8, 2022
wCaCO3/wBiomasa, esto para determinar experimentalmente los límites máximos de esta relación que ... more wCaCO3/wBiomasa, esto para determinar experimentalmente los límites máximos de esta relación que permitan una temperatura apta para la gasificación superior a 850°C. Como resultado de esta etapa se determinó que con una relación de 1% la temperatura de la gasificación estaría por debajo del límite planteado anteriormente. Una segunda etapa consistió en la valoración experimental del efecto del uso de CaCO 3 en el rendimiento operativo de planta piloto de gasificación con capacidad para generar 40kWe. Para este propósito se realizó una caracterización operativa y composición química del syngas producto de gasificación directa de tusa de maíz sin pretratamiento llamada una prueba base (B) y gasificación de tusa de maíz con presencia de CaCO3 con una relación peso/peso 1% CaCO3/Biomasa (BC). Los resultados obtenidos mostraron un incremento de 4% y 5% en los campos de CO y H2 respectivamente, ninguna variación en el campo de CH4 y una reducción de un 9% en el campo de CO2 producto de la gasificación con catálisis in situ del gasificador.
Energies
The United Nations established 17 Sustainable Development Goals (SDGs), and the fulfillment of th... more The United Nations established 17 Sustainable Development Goals (SDGs), and the fulfillment of the 7th, defined as “Ensure access to affordable, reliable, sustainable, and modern energy for all”, requires energy industry transitions and digital transformations, which implies that diverse stakeholders need to move fast to allow the growth of more flexible power systems. This paper contains the case report that addresses the commercial digital transformation process developed at AES Colombia, through the implementation of a modern platform based on specialized applications that use Industry 4.0 tools. The Chivor hydropower project, a 1000-MW powerplant that covers 6% of Colombia’s demand, which is owned by AES Colombia and constitutes its primary asset, is first described. Then, a description of Colombia’s complex market (energy matrix, trading and dispatch mechanisms, and future projects) is presented. Then, the methodology followed for the digital transformation process using modern...
Journal of Marine Science and Engineering, 2022
This paper addresses the development of a modular software architecture for the design/constructi... more This paper addresses the development of a modular software architecture for the design/construction/operation of a remotely operated vehicle (ROV), based on systems engineering. First, systems engineering and the Vee model are presented with the objective of defining the interactions of the stakeholders with the software architecture development team and establishing the baselines that must be met in each development phase. In the development stage, the definition of the architecture and its connection with the hardware is presented, taking into account the use of the actor model, which represents the high-level software architecture used to solve concurrency problems. Subsequently, the structure of the classes is defined both at high and low levels in the instruments using the object-oriented programming paradigm. Finally, unit tests are developed for each component in the software architecture, quality assessment tests are implemented for system functions fulfillment, and a field ...
Journal of Marine Science and Engineering, 2021
This paper addresses the development of a modular hardware architecture for the design/constructi... more This paper addresses the development of a modular hardware architecture for the design/construction/operation of a remotely operated vehicle (ROV), based on systems engineering. The Vee model is first presented as a sequential process that emphasizes the validation processes with stakeholders and verification plans in the development and production stages of the ROV’s life cycle. The conceptual design process starts with the mapping of user requirements to engineering specifications, using the House of Quality (HoQ), a quality function deployment tool that allows executing a functional-division-based hardware design process that facilitates the integration of components and subsystems, as desired for modular architectures. Then, the functional division and hardware architectures are described, and their connection is made through the proposed system architecture that sets the foundation for the definition of a physical architecture, as it involves flows that connect abstract functio...
Sustainability, 2022
This paper addresses the path followed by two private higher education institutions (HEI) in Colo... more This paper addresses the path followed by two private higher education institutions (HEI) in Colombia towards achieving carbon neutrality. The methodology followed by these universities to achieve a carbon-neutral certification, based on the Greenhouse Gas (GHG) Protocol, is first described. The process of developing the GHG inventory, projected towards the carbon neutrality of these organisations while using the standard ISO 14064:2006, involved a series of steps that were consolidated in three phases: (i) definition of the scope, collection of data and emissions quantification; (ii) analysis of results and mitigation actions; and (iii) verification and compensation strategies. Results for the HEIs are shown in terms of the organisational context, carbon footprint measurement, reduction, verification, and compensation. The case is presented for Universidad Pontificia Bolivariana, a multi-campus university that became the first carbon-neutral university in Latin America in 2017, and...
Water, 2020
Sedimentation is an important issue that has been studied for the watershed of reservoirs, since ... more Sedimentation is an important issue that has been studied for the watershed of reservoirs, since it increases operational costs of hydropower installations, reduces the life expectancy, and compromises the generation capacity due to volume reduction. This work addresses the implementation of Chivor’s Life Extension Project (CLEP), developed in order to extend the life of La Esmeralda reservoir, which is used for power generation in Colombia. Sediment dynamics studies are first described and connected to the need of the AES Corporation to extend the life expectancy of the Chivor Hydropower Project. The geotechnical and hydraulic designs are described and the main considerations and tools for the execution of such a project are addressed. The construction of the new intake system was developed under favorable geomorphological, geological, and hydrogeological conditions, and the project is being developed without affecting the current operation. Such an innovative project is the first ...
Ciencia y tecnología de buques, 2017
Designing a Remotely Operated Vehicle (ROV) is a complicated task in which the design team deals ... more Designing a Remotely Operated Vehicle (ROV) is a complicated task in which the design team deals with a considerable amount of uncertainty before the device is able to be tested at full scale. A way to cope with such uncertainty is to use simulation software to evaluate design concepts along the different levels of abstraction of the process. In this work, the use of aNySIM, the Maritime Research Institute Netherlands (MARIN) multibody time-domain simulation tool, as a part of the design process of an ROV is addressed. The simulation software is able to solve the equations of motion of the vehicle based on rigid body dynamics, including features such as hydrodynamics, hydrostatics, thrusters, thrust allocation, and PID control. Different simulation scenarios are proposed to evaluate different concept solutions to the design, including thruster parameters and distribution. The results are further used to select the concept solutions to be implemented in the final design.
Ingenieria Y Universidad, Oct 26, 2010
Resumen: se realiza una introducción a los sistemas tenségricos. Se muestran algunas definiciones... more Resumen: se realiza una introducción a los sistemas tenségricos. Se muestran algunas definiciones y la nomenclatura utilizada para los elementos de estas estructuras. Se describen las dos morfologías más utilizadas en el campo de la robótica y se describen algunas aplicaciones realizadas en el mundo: domos geodésicos, mástiles tenségricos para aplicaciones espaciales, robots tenségricos, sensores y actuadores. El grupo de Automática y Diseño (A+D), ha acumulado una experiencia importante con este tipo de sistemas; el grupo ha desarrollado proyectos, generado teorías y ha propuesto metodologías para el diseño y para el análisis de aplicaciones móviles basadas en sistemas tenségricos. El objetivo es introducir en Colombia este novedoso tema que plantea nuevas alternativas para la robótica.
Revista Cientifica Odontologica, Jul 15, 2010
DYNA, 2016
This paper reports on the design of an open source-based control platform for the underwater remo... more This paper reports on the design of an open source-based control platform for the underwater remotely operated vehicle (ROV) Visor3. The vehicle’s original closed source-based control platform is first described. Due to the limitations of the previous infrastructure, modularity and flexibility are identified as the main guidelines for the proposed design. This new design includes hardware, firmware, software, and control architectures. Open-source hardware and software platforms are used for the development of the new system’s architecture, with support from the literature and the extensive experience acquired with the development of robotic exploration systems. This modular approach results in several frameworks that facilitate the functional expansion of the whole solution, the simplification of fault diagnosis and repair processes, and the reduction of development time, to mention a few.
Revista Cientifica Odontologica, 2008
Formación universitaria, 2015
Se presenta el desarrollo de un equipo de laboratorio para el estudio, entrenamiento e investigac... more Se presenta el desarrollo de un equipo de laboratorio para el estudio, entrenamiento e investigación en control de procesos. Los requerimientos de diseño fueron determinados por usuarios de diferentes disciplinas relacionados con la academia, la investigación y tareas de entrenamiento a nivel de pregrado, postgrado y consultoría industrial. Se presenta el diseño de un proceso de nivel de líquido de dinámica variable (hasta tercer orden), interactuante, que permite incluir no linealidades y tiempo muerto variable. La estación experimental cuenta con tres opciones tecnológicas para el controlador: PLC, controlador industrial y computador portátil. Esta flexibilidad permite el uso de diversos algoritmos de control: PID, LQG, control difuso, control dinámico matricial y control con modos deslizantes, entre otros. El equipo propuesto cumple con los requisitos educativos incluidos en las tendencias contemporáneas de educación en ingeniería.
Ingeniería y Ciencia, 2015
Este artículo presenta una arquitectura para el diseño conceptual de vehículos subacuáticos opera... more Este artículo presenta una arquitectura para el diseño conceptual de vehículos subacuáticos operados remotamente (ROV). La arquitectura propuesta está basada en una revisión extensa de literatura y la experiencia obtenida durante 20 años con el desarrollo de tres sistemas ROV diseñados para misiones de inspección subacuática. El ROV se divide en cinco subsistemas: vehículo, estación en superficie, interfaz superficie/vehículo, sistema de control y software. Para cada uno de estos subsistemas se definen funciones y tareas, se enuncian componentes, se establecen interrelaciones con otros subsistemas y se plantean alternativas comúnmente utilizadas. La delimitación de los subsistemas desde el diseño conceptual busca evitar problemas en las fases avanzadas del desarrollo del sistema robótico de exploración.
Processes
This work addresses a set of tuning rules for PID controllers based on Internal Model Control (IM... more This work addresses a set of tuning rules for PID controllers based on Internal Model Control (IMC) for inverse-response second-order systems with dead time. The transfer function, and some time-response characteristics for such systems are first described. Then, the IMC-based methodology is developed by using an optimization objective function that mixes performance and robustness. A correlation that minimizes the objective function and that allows the user to compute the controller’s tuning parameter is found. The obtained expressions are mathematically simple, which facilitate their application in a ten-step systematic methodology. Finally, the proposed tuning method is compared to other well-known tuning rules that have been reported in literature, for a wide range of parameters of the process. The performance achieved with the proposed method is very good not only for disturbance rejection but for set-point tracking, when considering a wide-range of parameters of the process’ t...
IET Control Theory & Applications, 2013
This study investigates the observability problem and the observer design of partially observed f... more This study investigates the observability problem and the observer design of partially observed finite automata via a matrix approach. Using semi-tensor product of matrices, finite automata are modelled in the form of discrete-time bilinear systems. Matrix-form necessary and sufficient conditions for both the initial and current state observability, either with or without input information, are first proposed. Based on that, a constructive method for the observer design is provided. 2 Preliminary In this section, we introduce some useful concepts and preliminaries about the STP and the matrix expression for finite automata.
On the problem of potential shifts at glassy carbon electrodes
Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1985
The contribution of the heterogeneous (involving non-adsorbed solution species) and surface path ... more The contribution of the heterogeneous (involving non-adsorbed solution species) and surface path (involving adsorbed species) to the electrode processes of aromatic nitro compounds has been studied as a function of the surface conditions of glassy carbon (GC-20) by linear ...
2019 IEEE Intelligent Transportation Systems Conference (ITSC), Oct 1, 2019
A deep reinforcement learning based multi-objective autonomous braking system is presented. The d... more A deep reinforcement learning based multi-objective autonomous braking system is presented. The design of the system is formulated in a continuous action space and seeks to maximize both pedestrian safety and perception as well as passenger comfort. The vehicle agent is trained against a large naturalistic dataset containing pedestrian road-crossing trials in which respondents walked across a road under various traffic conditions within an interactive virtual reality environment. The policy for brake control is learned through computer simulation using two reinforcement learning methods i.e. Proximal Policy Optimization and Deep Deterministic Policy Gradient and the efficiency of each are compared. Results show that the system is able to reduce the negative influence on passenger comfort by half while maintaining safe braking operation.
Uploads
Papers by RAFAEL SEMINARIO VASQUEZ