Browsing by Autor "Nicanor Quijano"

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A bioinspired approach for a multizone temperature control system
(IOP Publishing, 2011) Andrés Pantoja; Nicanor Quijano; Sylvain Leirens
Bioinspired design approaches seek to exploit nature in order to construct optimal solutions for engineering problems as uniform temperature control in multizone systems. The ideal free distribution (IFD) is a concept from behavioural ecology, which describes the arrangement of individuals in different habitats such that at equilibrium, all habitats are equally suitable. Here, we relax the IFD's main assumptions using the standing-crop idea to introduce dynamics into the supplies of each habitat. Then, we make an analogy with a multizone thermal system to propose a controller based on the replicator dynamics model, in order to obtain a maximum uniform temperature subject to constant power injection. Besides, we analytically show that the equilibrium point of the controlled system is asymptotically stable. Finally, some practical results obtained with a testbed and comparisons with the theoretical results are presented.
Building Temperature Control Based on Population Dynamics
(Institute of Electrical and Electronics Engineers, 2013) Germán Obando; Andrés Pantoja; Nicanor Quijano
Temperature control in buildings is a dynamic resource allocation problem, which can be approached using nonlinear methods based on population dynamics (i.e., replicator dynamics). A mathematical model of the proposed control technique is shown, including a stability analysis using passivity concepts for an interconnection of a linear multivariable plant driven by a nonlinear control system. In order to illustrate our control strategy, some simulations are performed, and we compare our proposed technique with other control strategies in a model with a fixed structure. Finally, experimental results are shown in order to observe the performance of some of these strategies in a multizone temperature testbed.
Building Temperature Control Based on Replicator Dynamics
(Elsevier BV, 2010) Germán Obando; Andrés Pantoja; Nicanor Quijano
Defending State-Feedback Based Controllers Against Sensor Attacks
(Sergio A. Rojas, 2023) Luis Francisco Cómbita; Nicanor Quijano; Álvaro A. Cárdenas
Context: This paper is motivated by the need to improve the resilience of industrial control systems. Many control systems currently operating in the industry were designed and implemented before the boom in communications (wired and wireless networks) within industrial control systems. However, nowadays they operate connected to the communications network. This increase in connectivity has made the systems susceptible to cyber-attacks that seek to degrade the proper operation of the control loop even affecting only one sensor. Method: We use concepts from fault tolerant control and classic control theory to show that it is possible to reconstruct the system state without (any) one of the system outputs. This fact is used in the recalculation of the control signal through an algorithm of attack detection and isolation, to avoid for an attack to be feedback to the system, mitigating its effect. We show the effectiveness of our proposal with simulations on a four-tanks testbed using Matlab and Simulink. Results: We show that a bank of unknown input observers can be designed to recover true information from attacked sensors, i.e., recover the information without the effect of the attack. Therefore, the estimation obtained from those observers can be utilized for computing a control action that mitigates the effect of the attack. Conclusions: This mitigation of the attack prevents a single sensor attack from signi cantly impair the action of low-level controllers, improving the resilience on the system just modifying the digital controller architecture. The development presented is limited to cyber-attacks on system sensors pre- sented one at a time, that still can compromise seriously the system behavior. Future work will address the extension of the presented results in situations with simultaneous attacks on more than one sensor, and/or consider attacks on the control system actuators.
Honey Bee Social Foraging Algorithms for Resource Allocation, Part I: Algorithm and Theory
(Institute of Electrical and Electronics Engineers, 2007) Nicanor Quijano; Kevin M. Passino
A model of honey bee social foraging is introduced to create an algorithm that solves a class of optimal resource allocation problems. We prove that if several such algorithms compete in the same problem domain, the strategy they use is a special type of evolutionarily stable strategy. Moreover, for a single or multiple hives we prove that an ideal free distribution is achieved, and that the allocation strategy is globally optimal. In the companion paper [Quijano, N., et al., 2007] we illustrate the practical utility of these results via a multizone temperature control experiment.
Honey Bee Social Foraging Algorithms for Resource Allocation, Part II: Application
(Institute of Electrical and Electronics Engineers, 2007) Nicanor Quijano; Kevin M. Passino
Bioinspired solutions to technological problems exploit robust and optimal solutions evolved for biological systems via natural selection. In [1] a honey bee social foraging algorithm was introduced. It was shown that if several such algorithms ("hives") compete in the same problem domain, the strategy they use is a Nash equilibrium and that the allocation strategy is globally optimal. To illustrate the practical utility of the theoretical results and algorithm in this paper we show how it can solve a dynamic voltage allocation problem to achieve a maximum uniformly elevated temperature in an interconnected grid of temperature zones.
MICRORREDES AISLADAS EN LA GUAJIRA: DISEÑO E IMPLEMENTACIÓN
(Universidad de Los Andes, 2019) Nicanor Quijano; Angélica Pedraza; Miguel A. Velásquez; Guillermo Jiménez Estevez; Ángela Cadena; Jorge Mario Becerra; Álvaro Ramírez
This paper presents the design and implementation of an isolated microgrid developed in La Guajira, north of Colombia. It was designed through the collaboration and capacity building of the community itself. Several activities were developed by the research group in order to improve the technical design. With the objective of reaching a consensus in terms of the final desgin, several visits were made to the community. During the implementation, some new ideas on how to improve the design appeared. In any case, if the microgrid (that uses both solar and wind energy) would be replicated in any other location, we strongly recommend to include, from the beginning, the community needs and the ideas of its inhabitants.
Multi-Population Approach for Decentralized Control of Urban Drainage Systems with Replicator Dynamics
(2024) S. Higuera-Quintero; Nicanor Quijano
Using information consensus and replicator dynamics (RD), this article presents a distributed algorithm for designing control schemes in urban drainage systems (UDSs). It demonstrates the stability of a closed-loop model with RD in UDSs using passivity arguments for single subsystems. As central models for UDSs, we present two distinct topologies and conduct passivity-based analysis to design appropriate payoff mechanisms. We further extend this to a decentralized scenario in which subsystems within a UDS share information and increase capacity at specific sites in response to intense rainfall. This algorithm with distributed consensus assistance seeks to improve system performance. Several simulations are presented to illustrate the benefits of this method.
Optimal Distribution of UAVs in Crop Spraying Considering Energy Consumption
(2024) Oscar F. Archila; Nicanor Quijano; Juan Martinez-Piazuelo
The population growth rate has increased, leading to a need for new technologies like unmanned aerial vehicles (UAVs) to expand crop production and growth. UAVs are used in mapping, spraying, planting, crop monitoring, irrigation, and insect pest diagnosis. However, challenges such as maximum effective signal range, fuel limitations, uncovered crop areas, overlapped spraying, and pesticide waste need to be considered. In this context, we propose a multi-agent control method that associates the energy consumption with the total crop coverage. Our proposed method is able to generate the path planning for the UAVs considering a target density function, while the total flying time is decreased. The simulation results show that the proposed method decreases the total energy consumption with a negligible increment in the spray error.
Sum of squares decomposition: theory and applications in control
(National University of Colombia, 2010) Andrés Pantoja; Eduardo Mójica Nava; Nicanor Quijano
The sum of squares (SOS) decomposition technique allows numerical methods such as semidefinite programming to be used for proving the positivity of multivariable polynomial functions. It is well known that it is not an easy task to find Lyapunov functions for stability analysis of nonlinear systems. An algorithmic tool is used in this work for solving this problem. This approach is presented as SOS programming and solutions were obtained with a Matlab toolbox. Simple examples of SOS concepts, stability analysis for nonlinear polynomial and rational systems with uncertainties in parameters are presented to show the use of this tool. Besides these approaches, an alternative stability analysis for switched systems using a polynomial approach is also presented.