Combining reinforcement learning and conventional control to improve automatic guided vehicles tracking of complex trajectories

With the rapid growth of logistics transportation in the framework of Industry 4.0, automated guided vehicle (AGV) technologies have developed speedily. These systems present two coupled control problems: the control of the longitudinal velocity, essential to ensure the application requirements such as throughput and tag time, and the trajectory tracking control, necessary to ensure the proper accuracy in loading and unloading manoeuvres. When the paths are very short or have abrupt changes, the kinematic constraints play a restrictive role, and the tracking control becomes more challenging. In this case, advanced control strategies such as those based on intelligent techniques, including machine learning (ML) can be useful. Hence, in this work, we present an intelligent hybrid control scheme that combines reinforcement learning-based control (RLC) with conventional PI regulators to face both control problems simultaneously. On the one hand, PIs are used to control the speed of each wheel. On the other hand, the input reference of these regulators is calculated by the RLC in order to reduce the guiding error of the path tracking and to maintain the longitudinal speed. The latter is compared with a PID path following controller. The PID regulators have been tuned by genetic algorithms. The RLC allows the vehicle to learn how to improve the trajectory tracking in an adaptive way and thus, the AGV can face disturbances or unknown physical system parameters that may change due to friction and degradation of AGV mechanical components. Extensive simulation experiments of the proposed intelligent control strategy on a hybrid tricycle and differential AGV model, that considers the kinematics and the dynamics of the vehicle, prove the efficiency of the approach when following different demanding trajectories. The performance of the RL tracking controller in comparison with the optimized PID gives errors around 70% smaller, and the average maximum error is also 48% lower.Open access funding enabled and organized by Projekt DEAL

Hybrid Optimized Fuzzy Pitch Controller of a Floating Wind Turbine with Fatigue Analysis

Floating offshore wind turbines (FOWTs) are systems with complex and highly nonlinear dynamics; they are subjected to heavy loads, making control with classical strategies a challenge. In addition, they experience vibrations due to wind and waves. Furthermore, the control of the blade angle itself may generate vibrations. To address this issue, in this work we propose the design of an intelligent control system based on fuzzy logic to maintain the rated power of an FOWT while reducing the vibrations. A gain scheduling incremental proportional–derivative fuzzy controller is tuned by genetic algorithms (GAs) and combined with a fuzzy-lookup table to generate the pitch reference. The control gains optimized by the GA are stored in a database to ensure a proper operation for different wind and wave conditions. The software Matlab/Simulink and the simulation tool FAST are used. The latter simulates the nonlinear dynamics of a real 5 MW barge-type FOWT with irregular waves. The hybrid control strategy has been evaluated against the reference baseline controller embedded in FAST in different environmental scenarios. The comparison is assessed in terms of output power and structure stability, with up to 23% and 33% vibration suppression rate for tower top displacement and platform pitch, respectively, with the new control scheme. Fatigue damage equivalent load (DEL) of the blades has been also estimated with satisfactory results.This work has been partially supported by the Spanish Ministry of Science and Innovation under the project MCI/AEI/FEDER number RTI2018-094902-B-C21 and PDI2021-123543OB-C21

Frequencies identification of NREL 5MW ITI Barge Wind Turbine: first approach

In this work we present a process to identify the main frequencies that affects a floating offshores wind turbine (FOWT), specifically, the NREL 5MW ITI Barge Wind Turbine. This floating platform is highly affected by surge and sway translational movements due to the strong winds and mainly the waver it is subjected to. However, one of the most important modes is the 1st tower fore-aft bending mode, whose frequency has the same value than the forced 3P component, provoking these frequencies to be highly excited. In this work this effect is observed in the power spectrum of the tower top acceleration signal along the nacelle “x” axis.Peer Reviewe

Performance and Extreme Conditions Analysis Based on Iterative Modelling Algorithm for Multi-Trailer AGVs

Automatic guidance vehicles (AGV) are industrial vehicles that play an important role in the development of smart manufacturing systems and Industry 4.0. To provide these autonomous systems with the flexibility that is required today in these industrial workspaces, AGV computational models are necessary in order to analyze their performance and design efficient planning and control strategies. To address these issues, in this work, the mathematical model and the algorithm that implement a computational control-oriented simulation model of a hybrid tricycle-differential AGV with multi-trailers have been developed. Physical factors, such as wheel-ground interaction and the effect of vertical and lateral loads on its dynamics, have been incorporated into the model. The model has been tested in simulation with two different controllers and three trajectories: a circumference, a square, and an s-shaped curve. Furthermore, it has been used to analyze extreme situations of slipping and capsizing and the influence of the number of trailers on the tracking error and the control effort. This way, the minimum lateral friction coefficient to avoid slipping and the minimum ratio between the lateral and height displacement of the center of gravity to avoid capsizing have been obtained. In addition, the effect of a change in the friction coefficient has also been simulated

Glasius bio-inspired neural networks based UV-C disinfection path planning improved by preventive deadlock processing algorithm

The COVID-19 pandemic made robot manufacturers explore the idea of combining mobile robotics with UV-C light to automate the disinfection processes. But performing this process in an optimum way introduces some challenges: on the one hand, it is necessary to guarantee that all surfaces receive the radiation level to ensure the disinfection; at the same time, it is necessary to minimize the radiation dose to avoid the damage of the environment. In this work, both challenges are addressed with the design of a complete coverage path planning (CCPP) algorithm. To do it, a novel architecture that combines the glasius bio-inspired neural network (GBNN), a motion strategy, an UV-C estimator, a speed controller, and a pure pursuit controller have been designed. One of the main issues in CCPP is the deadlocks. In this application they may cause a loss of the operation, lack of regularity and high peaks in the radiation dose map, and in the worst case, they can make the robot to get stuck and not complete the disinfection process. To tackle this problem, in this work we propose a preventive deadlock processing algorithm (PDPA) and an escape route generator algorithm (ERGA). Simulation results show how the application of PDPA and the ERGA allow to complete complex maps in an efficient way where the application of GBNN is not enough. Indeed, a 58% more of covered surface is observed. Furthermore, two different motion strategies have been compared: boustrophedon and spiral motion, to check its influence on the performance of the robot navigation

Expresiones de resistencia Afrocaribe: La mirada decolonial en la obra poética de Jorge Artel

Hablar de resistencia afrocaribe, conduce a recrear la memoria y caminos trasegados por hombres y mujeres como Candelario Obeso, Luis Antonio Robles, Juan, Delia y Manuel Zapata Olivella, Aquiles Escalante y Jorge Artel, entre otros; quienes nos legaron su palabra y su compromiso en la lucha por la identidad, la recuperación y dignificación de la memoria del pueblo afrodescendiente, a través de su producción intelectual, como investigadores, narradores, folcloristas y poetas. Este ensayo hace referencia en clave decolonial al poeta Jorge Artel. Poeta de su raza y de su gente, de sus tambores y de protestas llenas de vida, de negritud, de emoción sin límites, de angustia ancestral y llamado de la sangre. Jorge Artel intuyó, supo, comprendió, que la modernidad es un pozo negro que con la retórica del progreso, oculta sus consecuencias, así como también oculta la energía irreductible de los marginados y excluidos de la tierra

Residuos de pesticidas organoclorados en cerebro e hígado de truchas (Salmo Trutta Fario, L.)

[ES] Residuos de pesticidas organoclorados en cerebro e hígado de truchas (Salmo Trutta Fario, L.

Recombinant AMP/Polypeptide Self-Assembled Monolayers with Synergistic Antimicrobial Properties for Bacterial Strains of Medical Relevance

Producción CientíficaNosocomial infections are one of the most frequent causes of indwelling biomedical device failure. In this regard, the use of antibiofilm nanocoatings based on antimicrobial peptides (AMPs) is a promising alternative to prevent multiresistant biofilm infections. However, the limitations of chemical production impede the large-scale development of advanced antimicrobial materials that improve the properties of AMPs. Herein, we present a multifunctional modular design for the recombinant coproduction of self-assembled monolayers (SAMs) based on AMPs and elastin-like recombinamers (ELRs), which combine the antimicrobial properties of a designer AMP, GL13K, and low-fouling activity of an ELR in a synergistic manner. The inclusion of a grafting domain intended for oriented tethering onto surfaces allowed the recombinant polymers to be covalently immobilized onto model gold surfaces. The antibiofilm properties against two of the bacterial strains most frequently responsible for indwelling medical device-associated infections, namely Staphylococcus epidermidis and Staphylococcus aureus, were then evaluated. GL13K peptide was found to provide antibiofilm properties to the surface, with these being synergistically enhanced by the antifouling effect of the ELR. This new design offers a promising tool for the development of advanced AMP-based nanocoatings for medical devices with powerful and enhanced features.Comisión Europea (project NMP-2014-646075)Ministerio de Economía, Industria y Competitividad (project PCIN-2015-010 / MAT2015-68901-R / MAT2016-78903-R)Junta de Castilla y León (project VA317P18

The Pharmacokinetics and interactions of ivermectin in humans—A mini-review

P. 42-46Ivermectin is an antiparasitic drug with a broad spectrum of activity, high efficacy as well as a wide margin of safety. Since 1987, this compound has a widespread use in veterinary medicine and it use has been extended in humans. Here we present a brief review of the information availabile regarding the pharmacokinetics and interactions of ivermectin in humans. Awareness of these characteristics could improve the clinical efficacy of Ivermectin. All Authors declare that they do not have any Conflict of interest and that the work is original. All Authors agree that the contents of the manuscript are confidential and will not be copyrighted, submitted, or published elsewhere (including the Internet), in any language, while acceptance by the Journal is under consideration.S

The pharmacokinetics and metabolism of ivermectin in domestic animal species

P. 25-37The pharmacokinetic properties of drugs are closely related to their pharmacological efficacy. The kinetics of ivermectin are characterised, in general terms, by a slow absorption process, a broad distribution in the organism, low metabolism, and slow excretion. The kinetics vary according to the route of administration, formulation, animal species, body condition, age, and physiological status, all of which contribute to differences in drug efficacy. Characterisation of ivermectin kinetics can be used to predict and optimise the value of the parasiticide effects and to design programmes for parasite control. This article reviews the pharmacokinetics of ivermectin in several domestic animal species.S