Artículos (Ingeniería de Sistemas y Automática)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/11342

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A 3D time domain numerical model based on half-space Green's function for soil-structure interaction analysis
(Springer, 2014) Galvín, Pedro; Maestre Torreblanca, José María; Romero Ordóñez, Antonio; ; Universidad de Sevilla. Departamento de Mecánica de Medios Continuos y Teoría de Estructuras; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Universidad de Sevilla. TEP245: Ingeniería de las Estructuras
This paper presents a numerical method based on a three dimensional boundary element-finite element (BEM- FEM) coupled formulation in the time domain. The proposed model allows studying soil-structure interaction problems. The soil is modelled with the BEM, where the radiation condition is implicitly satisfied in the fundamental solution. Half-space Green's function including internal soil damping is considered as the fundamental solution. An effective treatment based on the integration into a complex Jordan path is proposed to avoid the singularities at the arrival time of the Rayleigh waves. The efficiency of the BEM is improved taking into account the spatial symmetry and the invariance of the fundamental solution when it is expressed in a dimensionless form. The FEM is used to represent the structure. The proposed method is validated by comparison with analytical solutions and numerical results presented in the literature. Finally, a soil-structure interaction problem concerning with a building subjected to different incident wave fields is studied
A 79.7g Manipulator Prototype for E-Flap Robot: A Plucking-Leaf Application
(IEEE, 2022-06-17) Nekoo, Saeed Rafee; Feliu-Talegon, Daniel; Acosta Rodríguez, José Ángel; Ollero Baturone, Aníbal; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Consejo Europe de Investigación (ERC) - Proyecto GRIFFIN Action 788247; Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI) Proyecto HOMPOT PY20_00597; Universidad de Sevilla. TEP151: Robótica, Visión y Control
The manipulation capabilities of flapping-wing flying robots (FWFRs) is a problem barely studied. This is a direct consequence of the load-carrying capacity limitation of the flapping-wing robots. Ornithopters will improve the existent multirotor unmanned aerial vehicles (UAVs) since they could perform longer missions and offer a safe interaction in proximity to humans. This technology also opens the possibility to perch in some trees and perform tasks such as obtaining samples from nature, enabling biologists to collect samples in remote places, or assisting people in rescue missions by carrying medicines or first-aid kits. This paper presents a very lightweight manipulator (79.7g) prototype to be mounted on an ornithopter. The distribution of the mass on the flapping-wing robot is sensitive and an extra lumped mass far from the center-of-mass (CoM) of the robot deteriorates the flight stability. A configuration was proposed to avoid changing the CoM. Flight experiments show that adding the arm to the robot only moved the CoM 6mm and the performance of the flight with the manipulator has been satisfactory. Plucking leaf is chosen as an application to the designed system and several experimental tests confirmed successful sampling of leaves by the prototype.
A 94.1 g scissors-type dual-arm cooperative manipulator for plant sampling by an ornithopter using a vision detection system
(Cambridge University Press, 2023) Nekoo, Saeed Rafee; Feliu Talegón, Daniel; Tapia López, Raúl; Satué, Álvaro C.; Martínez de Dios, José Ramiro; Ollero Baturone, Aníbal; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Unión Europea; Ministerio de Ciencia, Innovación y Universidades (MICINN). España; Universidad de Sevilla. TEP151: Robótica, Visión y Control
The sampling and monitoring of nature have become an important subject due to the rapid loss of green areas. This work proposes a possible solution for a sampling method of the leaves using an ornithopter robot equipped with an onboard 94.1 g dual-arm cooperative manipulator. One hand of the robot is a scissors-type arm and the other one is a gripper to perform the collection, approximately similar to an operation by human fingers. In the move toward autonomy, a stereo camera has been added to the ornithopter to provide visual feedback for the stem, which reports the position of the cutting and grasping. The position of the stem is detected by a stereo vision processing system and the inverse kinematics of the dual-arm commands both gripper and scissors to the right position. Those trajectories are smooth and avoid any damage to the actuators. The real-time execution of the vision algorithm takes place in the lightweight main processor of the ornithopter which sends the estimated stem localization to a microcontroller board that controls the arms. The experimental results both indoors and outdoors confirmed the feasibility of this sampling method. The operation of the dual-arm manipulator is done after the perching of the system on a stem. The topic of perching has been presented in previous works and here we focus on the sampling procedure and vision/manipulator design. The flight experimentation also approves the weight of the dual-arm system for installation on the flapping-wing flying robot.
A benchmark mechatronics platform to assess the inspection around pipes with variable pitch quadrotor for industrial sites
(Elsevier Ltd, 2021) Nekoo, Saeed Rafee; Acosta Rodríguez, José Ángel; Heredia Benot, Guillermo; Ollero Baturone, Aníbal; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; European Union (UE). H2020; Agencia Estatal de Investigación española
This paper investigates the inspection-of-pipe topic in a new framework, by rotation around a pipe, peculiar to industrial sites and refineries. The evolution of the ultimate system requires prototype design and preliminary tests. A new benchmark has been designed and built to mimic the rotation around a pipe, with the main purpose of assessing the different types of rotors and control systems. The benchmark control system presents a mechatronics package including mechanical design and machining, electronics and motor drive, motor-blade installation, computer programming, and control implementation. The benchmark is also modular, working with two modes of one- and two-degree-of-freedom (DoF), easily interchangeable. To cover a full rotation, conventional fixed-pitch drones fail to provide negative thrusts; nonetheless, variable-pitch (VP) rotor quad- copters can produce that in both directions. A closed-loop nonlinear optimal method is chosen as a controller, so- called, “the state-dependent Riccati equation (SDRE)” approach. Optimal control policies are challenging for experimentation though it has been successfully done in this report. The advantage of the VP is also illustrated in a rotation plus radial motion in comparison with fixed-pitch rotors while a wind gust disturbs the inspection task. The proposed VP system compensated the disturbance while the fixed pitch was pushed away by the wind gust. The solution methods to the SDRE were mixed, a closed-form exact solution for the one-DoF system, and a numerical one for the two-DoF. Solving the Riccati online in each time step is a critical issue that was effectively solved by the implementation approach, through online communication with MATLAB software. Both simula- tions and experiments have been performed along with a discussion to prove the application of VP systems in rotary-motion pipe inspection
A Bio-Inspired Manipulator with Claw Prototype for Winged Aerial Robots: Benchmark for Design and Control
(MDPI AG, 2020) Feliu-Talegon, Daniel; Acosta Rodríguez, José Ángel; Suárez Fernández-Miranda, Alejandro; Ollero Baturone, Aníbal; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Universidad de Sevilla. TEP -151 Robótica, Visión y Control
Nature exhibits many examples of birds, insects and ﬂying mammals with ﬂapping wings and limbs offering some functionalities. Although in robotics, there are some examples of ﬂying robots with wings, it has not been yet a goal to add to them some manipulation-like capabilities, similar to ones that are exhibited on birds. The ﬂying robot (ornithopter) that we propose improves the existent aerial manipulators based on multirotor platforms in terms of longer ﬂight duration of missions and safety in proximity to humans. Moreover, the manipulation capabilities allows them to perch in inaccessible places and perform some tasks with the body perched. This work presents a ﬁrst prototype of lightweight manipulator to be mounted to an ornithopter and a new control methodology to balance them while they are perched and following a desired path with the end effector imitating their beaks. This allows for several possible applications, such as contact inspection following a path with an ultrasonic sensor mounted in the end effector. The manipulator prototype imitates birds with two-link legs and a body link with an actuated limb, where the links are all active except for the ﬁrst passive one with a grabbing mechanism in its base, imitating a claw. Unlike standard manipulators, the lightweight requirement limits the frame size and makes it necessary to use micro motors. Successful experimental results with this prototype are reported.
A Bound on the Existence of the Maximum Jointly Invariant Set of Input-Coupled Systems
(IEEE (Institute of Electrical and Electronics Engineers), 2023) Sánchez Amores, Ana; Maestre Torreblanca, José María; Trodden, Paul A.; Camacho, Eduardo F.; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática
We present a set-theoretical characterization of a bound on the maximal portion that an agent can cede of its input variable to another agent. By ceding control authority, agents can decompose coupling variables into public and private parts, which is of interest in situations of partial cooperation. In particular, sufficient conditions under which the non-existence of the maximum robust control invariant set is guaranteed are provided, expressed in terms of support functions and the dominant system eigenvalue. Finally, the results are illustrated via stable and unstable example systems with different coupling.
A cascade neural network methodology for fault detection and diagnosis in solar thermal plants
(Elsevier, 2023-07) Ruiz-Moreno, Sara; Gallego Len, Antonio Javier; Sánchez, Adolfo J.; Camacho, Eduardo F.; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; European Research Council (ERC); Ministerio de Ciencia, Innovación y Universidades (MICINN). España; Universidad de Sevilla. TEP-116: Automática y robótica industrial
Detecting and isolating faults in collector fields of solar thermal power plants is a crucial and challenging task. The system variables in the collector area are highly coupled, which can lead to a high misclassification rate. For this reason, it becomes necessary to combine knowledge of systems engineering with machine learning techniques that unravel the complex dynamics that govern the systems using historical data. Furthermore, the performance of a solar thermal plant is highly dependent on solar irradiance which changes during the day and is subject to perturbations caused by clouds and other atmospheric conditions. Detecting the fault requires using techniques that cope with the disturbances in solar irradiance. In this work, real irradiance profiles with many types of clouds are used. First, a model-based fault detector is applied, obtaining an accuracy of over 89% for all test irradiances. Then, different machine learning techniques are compared: static neural networks with and without decoupling strategy, dynamic neural networks, dynamic neural networks in cascade, classification trees, random forests, radial basis function networks, and self-organizing maps. The combination of neural networks was the only method that obtained a total accuracy of over 73% and F1-scores over 50% for all the test irradiance profiles.
A Coalitional Model Predictive Control for the Energy Efficiency of Next-Generation Cellular Networks
(MDPI, 2020-12) Masero Rubio, Eva; A. Fletscher, Luís; Maestre Torreblanca, José María; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Universidad de Sevilla. TEP -116 Automática y Robótica Industrial
Next-generation cellular networks are large-scale systems composed of numerous base stations interacting with many diverse users. One of the main challenges with these networks is their high energy consumption due to the expected number of connected devices. We handle this issue with a coalitional Model Predictive Control (MPC) technique for the case of next-generation cellular networks powered by renewable energy sources. The proposed coalitional MPC approach is applied to two simulated scenarios and compared with other control methods: the traditional best-signal level mechanism, a heuristic algorithm, and decentralized and centralized MPC schemes. The success of the coalitional strategy is considered from an energy efficiency perspective, which means reducing on-grid consumption and improving network performance (e.g., number of users served and transmission rates).
A Compound Current Limiter and Circuit Breaker
(MDPI, 2019-05) Heidary, Amir; Radmanesh, Hamid; Bakhshi, Ali; Rouzbehi, Kumars; Pouresmaeil, Edris; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática
The protection of sensitive loads against voltage drop is a concern for the power system. A fast fault current limiter and circuit breaker can be a solution for rapid voltage recovery of sensitive loads. This paper proposes a compound type of current limiter and circuit breaker (CLCB) which can limit fault current and fast break to adjust voltage sags at the protected buses. In addition, it can act as a circuit breaker to open the faulty line. The proposed CLCB is based on a series L-C resonance, which contains a resonant transformer and a series capacitor bank. Moreover, the CLCB includes two anti-parallel power electronic switches (a diode and an IGBT) connected in series with bus couplers. In order to perform an analysis of CLCB performance, the proposed structure was simulated using MATLAB. In addition, an experimental prototype was built, tested, and the experimental results were reported. Comparisons show that experimental results were in fair agreement with the simulation results and confirm CLCB’s ability to act as a fault current limiter and a circuit breaker.
A controller for practical stability of capacitor voltages in a ﬁve-level diode-clamped converter
(Elsevier, 2016-09) Umbría Jiménez, Francisco; Gordillo Álvarez, Francisco; Salas Gómez, Francisco; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Universidad de Sevilla. TEP-102
The balancing of the dc-link capacitor voltages represents the main technical challenge in multilevel diode-clamped converters. In particular, when the number of capacitors is greater than two, these power conversion systems must be actively controlled to achieve a correct voltage sharing. Focusing on the ﬁve-level diode-clamped converter topology, this paper deals with the voltage imbalance phenomenon from a control point of view. For that purpose, the voltage balancing objective is addressed as a problem of ensuring the practical stability of a nonlinear system under the presence of external disturbances. Considering this approach, a novel control method is proposed to regulate the outputs of the system. It is based on several steps, which should be carried out during the controller design stage, that lead to deﬁne a discrete-time controller with sampling frequency corresponding to the triple of the ac-source frequency. Finally, the performance of the proposed controller is analyzed under varying operating conditions to demonstrate the capability and viability of the controller to attain the control goals.
A Data-Driven Based Voltage Control Strategy for DC-DC Converters: Application to DC Microgrid
(MDPI AG, 2019-05) Rouzbehi, Kumars; Miranian, Arash; Escaño González, Juan Manuel; Rakhshani, Elyas; Shariati, Negin; Pouresmaeil, Edris; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática
This paper develops a data-driven strategy for identification and voltage control for DC-DC power converters. The proposed strategy does not require a pre-defined standard model of the power converters and only relies on power converter measurement data, including sampled output voltage and the duty ratio to identify a valid dynamic model for them over their operating regime. To derive the power converter model from the measurements, a local model network (LMN) is used, which is able to describe converter dynamics through some locally active linear sub-models, individually responsible for representing a particular operating regime of the power converters. Later, a local linear controller is established considering the identified LMN to generate the control signal (i.e., duty ratio) for the power converters. Simulation results for a stand-alone boost converter as well as a bidirectional converter in a test DC microgrid demonstrate merit and satisfactory performance of the proposed data-driven identification and control strategy. Moreover, comparisons to a conventional proportional-integral (PI) controllers demonstrate the merits of the proposed approach.
A decentralized approach for the aerial manipulator robust trajectory tracking
(PLOS, 2024-03) Tlatelpa-Osorio, Yarai Elizabeth; Rodríguez-Cortés, Hugo; Acosta Rodríguez, José Ángel; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Consejo Nacional de Ciencia y Tecnología (CONACYT). México; Universidad de Sevilla. TEP995: Multi-robot And Control Systems
This paper introduces a new decentralized control strategy for an unmanned aerial manipulator (UAM) constrained to the vertical plane. The control strategy comprises two loops: the first compensates for the aerial vehicle’s impact on the manipulator; and the second one implements independent controllers for the aerial vehicle and the manipulator. The controller for the aerial vehicle includes an estimator to compensate for the dynamic influence of the manipulator, even if it is affected by external wind-gust disturbances. The manipulator has two revolute joints; however, it is modeled as an dynamically equivalent manipulator, with one revolute and one prismatic joint. The proposed control strategy’s performance is evaluated using a simulator that includes the vehicle’s aerodynamics and the manipulator’s contact force and moment.
A deep learning-based strategy for fault detection and isolation in parabolic-trough collectors
(Elsevier, 2022-03) Ruiz-Moreno, Sara; Sánchez, Adolfo J.; Gallego Len, Antonio Javier; Camacho, Eduardo F.; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Universidad de Sevilla. TEP-116: Automática y robótica industrial.
Solar plants are exposed to the appearance of faults in some of their components, as they are vulnerable to the action of external agents (wind, rain, dust, birds …) and internal defects. However, it is necessary to ensure a satisfactory operation when these factors affect the plant. Fault detection and diagnosis methods are essential to detecting and locating the faults, maintaining efficiency and safety in the plant. This work proposes a methodology for detecting and isolating faults in parabolic-trough plants. It is based on a three-layer methodology composed of a neural network to obtain a preliminary detection and classification between three types of fault, a second stage analyzing the flow rate dynamics, and a third stage defocusing the first collector to analyze thermal losses. The methodology has been applied by simulation to a model of the ACUREX plant, which was located at the Plataforma Solar de Almería. The confusion matrices have been obtained, with accuracies over 80% when using the three layers in a hierarchical structure. By forcing all the three layers, the accuracies exceed 90%.
A descomposition Algorithm for Feedback Min-Max Model predictive Control
(Institute of Electrical and Electronics Engineers (IEEE), 2006) Muñoz de la Peña Sequedo, David; Alamo, Teodoro; Bemporad. A.; Camacho, Eduardo F.; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática
An algorithm for solving feedback min-max model predictive control for discrete-time uncertain linear systems with constraints is presented in this note. The algorithm is based on applying recursively a decomposition technique to solve the min-max problem via a sequence of low complexity linear programs. It is proved that the algorithm converges to the optimal solution in finite time. Simulation results are provided to compare the proposed algorithm with other approaches
A family of smooth controllers for swinging up a pendulum
(2008) Aström, K. J.; Aracil Santonja, Javier; Gordillo Álvarez, Francisco; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Ministerio de Ciencia y Tecnología (MCYT). España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER)
The paper presents a new family of controllers for swinging up a pendulum. The swinging up of the pendulum is derived from physical arguments based on two ideas: shaping the Hamiltonian for a system without damping; and providing damping or energy pumping in relevant regions of the state space. A family of simple smooth controllers without switches with nice properties is obtained. The main result is that all solutions that do not start at a zero Lebesgue measure set converge to the upright position for a wide range of the parameters in the control law. Thus, the swing-up and the stabilization problems are simultaneously solved with a single, smooth law. The properties of the solution can be modiﬁed by the parameters in the control law. Control signal saturation can also be taken into account using the Hamiltonian approach.
A fast implementation of coalitional model predictive controllers based on machine learning: Application to solar power plants
(Elsevier, 2023) Masero Rubio, Eva; Ruiz-Moreno, Sara; Domínguez Frejo, José Ramón; Maestre Torreblanca, José María; Camacho, Eduardo F.; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Ministerio de Ciencia e Innovación (MICIN). España; Ministerio de Ciencia e Innovación (MICIN). España; Ministerio de Ciencia e Innovación (MICIN). España; Ministerio de Ciencia e Innovación (MICIN). España
This article proposes a real-time implementation of distributed model predictive controllers to maximize the thermal energy generated by parabolic trough collector fields. For this control strategy, we consider that each loop of the solar collector field is individually managed by a controller, which can form coalition with other controllers to attain its local goals while contributing to the overall objective. The formation of coalitions is based on a market-based mechanism in which the heat transfer fluid is traded. To relieve the computational burden online, we propose a learning-based approach that approximates optimization problems so that the controller can be applied in real time. Finally, simulations in a -loop solar collector field are used to assess the coalitional strategy based on neural networks in comparison with the coalitional model predictive control. The results show that the coalitional strategy based on neural networks provides a reduction in computing time of up to and a minimal reduction in performance compared to the coalitional model predictive controller used as the baseline.
A Game Theoretical Randomized Method for Large-Scale Systems Partitioning
(IEEE, 2018) Muros Ponce, Francisco Javier; Maestre Torreblanca, José María; Ocampo-Martínez, Carlos; Algaba Durán, Encarnación; Camacho, Eduardo F.; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Universidad de Sevilla. Departamento de Matemática Aplicada II (ETSI); European Union (UE); Ministerio de Economía y Competitividad (MINECO). España
In this paper, a game theory-based partitioning algorithm for large-scale systems (LSS) is proposed. More speci cally, a game over nodes is introduced in a model predictive control framework. The Shapley value of this game is used to rank the communication links of the control network based on their impact on the overall system performance. A randomized method to estimate the Shapley value of each node and also an ef cient redistribution of the resulting value to the links involved are considered to relieve the combinatorial explosion issues related to LSS. Once the partitioning solution is obtained, a sensitivity analysis is proposed to give a measure of its performance. Likewise, a greedy ne tuning procedure is considered to increase the optimality of the partitioning results. The full Barcelona drinking water network is analyzed as a real LSS case study, showing the effectiveness of the proposed approach in comparison with other partitioning schemes available in the literature.
A hybrid active load and ideal synchronous condenser-based model for STATCOM applied to power flow studies
(Institution of Engineering and Technology (IET), 2019) Karami, Ehsan; Gharehpetian, Gevork B.; CheshmehBeigi, Hassan Moradi; Rouzbehi, Kumars; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática
This study proposes a generalised STATCOM model employing active load and ideal synchronous condenser representation and its related power flow solution. The proposed method considers the effects of DC side voltage, internal switching losses, and operation mode on the power flow problem. To such aim, the proposed model tackles with a tap changing transformer accompanied by a variable conductance at the DC side in order to model the switching losses. This model can also take into account voltage regulation, reactive power control as well as amplitude modulation ratio and practical limitations. It is worth noting that the proposed model can be easily used for power flow studies by applying ordinary changes to the prevalent Newton–Raphson-based power flow methods. The introduced model is applied to two test systems including IEEE 14-Bus system, followed by a discussion on results.
A light clustering model predictive control approach to maximize thermal power in solar parabolic-trough plants
(Springer, 2021) Masero Rubio, Eva; Domínguez Frejo, José Ramón; Maestre Torreblanca, José María; Camacho, Eduardo F.; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática
This article shows how coalitional model predictive control (MPC) can be used to maximize thermal power of large-scale solar parabolic-trough plants. This strategy dynamically generates clusters of loops of collectors according to a given criterion, thus dividing the plant into loosely coupled subsystems that are locally controlled by their corresponding loop valves to gain performance and speed up the computation of control inputs. The proposed strategy is assessed with decentralized and centralized MPC in two simulated solar parabolic-trough fields. Finally, results regarding scalability are also given using these case studies.
A Lightweight Beak-Like Sensing System for Grasping Tasks of Flapping Aerial Robots
(IEEE, 2022-04) Feliu-Talegon, Daniel; Acosta Rodríguez, José Ángel; Feliu-Battle, Vicente; Ollero Baturone, Aníbal; Universidad de Sevilla. Departamento de Ingeniería de Sistemas y Automática; Universidad de Sevilla. TEP151: Robótica, Visión y Control
Many sensor systems in robotics are bio-inspired by similar mechanisms in living creatures. Birds frequently use their beaks to grasp and manipulate objects. This work proposes a very lightweight sensor system that emulates a bird’s beak, thus allowing flapping aerial robots to interact with the environment, as e.g. to perform grasping or manipulation tasks. The sensor system is composed of a flexible link (beam) actuated by a micro servomotor, two strain gauges placed on different points and a rigid link opposed. Additionally, a new algorithm is also developed that estimates the instant at which the beak impacts with an object, the contact position and the exerted force. Our sensor system outperforms the existing designs in robotics applications, because it is lightweight, small, cheap, with very low computational load and without any complementary perception. It is demonstrated that the adequate placement of two strain gauges allow the estimation of the contact point and the force exerted between the beam and an object, and the accuracy achieved is enough to reckon properties of the object and develop force control systems. The validation has been made and reported through finite-element simulations and experiments, and the results illustrate the efficiency of the prototype and the proposed algorithm.

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