Gian Carlo Daraviña-Peña

Material extrusion (MEX) builds parts from discrete polymer beads, so the cross-section that carries a tensile load is the union of the deposited beads rather than the rectangle measured with a caliper, and it varies with the infill pattern and along the gauge length. Digital models that reconstruct this section from the G-code need an estimator of the load-bearing area that is fast and geometrically faithful. We compare four estimators on identical toolpaths: a line–plane intersection point-count index (R_LPI), the additive sum of elliptical bead sections, the rasterized union of those sections and an obliquity-corrected union. The corpus comprises 357 ASTM D638 Type V toolpaths (17 infill patterns, seven densities, three layer heights) cut by 77 transverse planes, with the width of every bead read from the slicer output. Additive summation overestimates the union area by 3.1% to 10.6% because neighboring beads overlap; obliquity adds 0.9% on average. The point-count index and the minimum union area rank the patterns differently: six of the seventeen patterns move by seven positions or more between the two orderings, Hilbert curve from 14th by point count to 3rd by union area and Lightning from 6th to 16th, while the rank correlation between the two orderings is weak and does not reach significance (Spearman ρ_s = 0.36, p = 0.15, n = 17). The two estimators also locate the minimum section to be 1.83 mm apart on average, 24% of the gauge length. Sensitivity analyses on the sectioning interval, the obliquity cap, the tie-handling rule and the bead cross-section model leave these conclusions unchanged. Within this purely geometric scope, a self-normalized point count does not reproduce the solid area of the section across infill topologies; which estimator better predicts strength and fracture location remains to be tested experimentally.

Access to reliable water quality monitoring remains a significant challenge in rural and underserved regions, where laboratory-based analyses are often constrained by logistical and economic limitations. This study presents the design and functional laboratory-scale implementation of a low-cost IoT-based monitoring platform intended to support the digitalization of decentralized water treatment and water management through remote assessment of pH, temperature, electrical conductivity, dissolved oxygen, and turbidity. The proposed architecture integrates commercial sensors within a valve-controlled hydraulic chamber that performs intermittent fill–retain–measure–drain cycles, a Pycom LoPy 4.0 acquisition unit, LoRaWAN-based data forwarding, and cloud-based visualization. Functional testing demonstrated successful end-to-end integration of the hydraulic, sensing, communication, and visualization subsystems under controlled prototype conditions. The minimum demonstrated operational cycle was approximately 90 s; however, this value corresponded to the shortest functional testing condition rather than the intended routine monitoring interval, which incorporates a configurable inactive period between consecutive measurement cycles. The results demonstrate the feasibility of integrating low-cost sensing technologies, intermittent hydraulic sampling, and LoRaWAN connectivity into a laboratory-scale engineering prototype for decentralized water quality monitoring. The proposed platform should therefore be regarded as a functional proof-of-concept that establishes the technological basis for future metrological validation, long-term field deployment, and integration with decentralized water treatment systems rather than as a fully validated monitoring instrument.

Digital twin (DT) technology is transforming industrial automation by enabling the real-time simulation, predictive control, and optimization of complex systems. This study presents a DT-based kinematic control method designed for trajectory planning and execution in a 2RRR planar parallel manipulator. The framework utilizes ROS/Gazebo for virtual modeling and MATLAB’s Guide tool for a human–machine interface, establishing a synchronized virtual–physical environment. By dynamically bridging design and manufacturing phases, the DT model enhances operational insight through real-time data exchange and control flexibility. Statistical analyses, including the comparative hypothesis testing of angular positions and velocities with a 95% confidence level, validate the model’s precision, demonstrating a high degree of fidelity between the virtual model and the physical system. These findings confirm the DT’s reliability as an effective tool for trajectory programming, highlighting its potential in industrial robotics where adaptability and data-driven decision making are essential. This approach contributes to the evolving landscape of Industry 4.0 by supporting intelligent manufacturing systems with improved accuracy and efficiency.

This study introduces a novel methodology integrating computer vision, visual servo control, and the Kalman Filter to precisely estimate object locations for a 3-RRR planar type parallel manipulator. Through kinematic analysis and the development of a vision system using color indicators, the research enhances the ability of the manipulator to track object trajectories, especially in cases of occlusion. Employing Eye-to-Hand visual servo control, the research further refines the visual orientation of the sensor for optimal end effector and object identification. The incorporation of the Kalman Filter as a robust estimator for occluded objects underscores the predictive accuracy of the system. Results demonstrate the effectiveness of the methodology in trajectory generation and object tracking, with potential implications for improving robotic manipulators in dynamic environments. This comprehensive approach not only advances the fields of kinematic control and visual servoing but also opens new avenues for future research in complex spatial manipulations.

This paper presents the development of a graphical interface implemented in a 3-RRR planar parallel manipulator. The graphical interface allows the control, in open loop, of the position of the manipulator, allowing to locate in the plane the end actuator and define its pose. The graphical interface allows the visualization of variables such as angular position, torque, voltage of the servomotors that drive the input links. The theoretical and real comparison of the angular displacement and the torque in the motors during the chosen path is shown, obtaining very close results between both.

Debido a necesidades de la industria como incrementar la producción y realizar tareas peligrosas para el hombre, se desarrollaron mecanismos automatizados que realizan operaciones de producción de manera más rápida, segura y económica. A estos mecanismos automatizados se les llamó robots. Los robots fueron diseñados y construidos desde hace varias décadas con el objetivo de prestar servicios a los humanos en tareas repetitivas; en la industria, los robots se emplean para elaborar trabajos de pintura, soldadura, ensamble de piezas, entre otros. En el área aeroespacial, han sido utilizados como rescatadores de satélites, en la recolección de muestras, en la exploración de terrenos y para labores de mantenimiento de las estaciones espaciales. Muchas aplicaciones que hace décadas se consideraban imposibles de realizar, hoy son realidad. Existe una gran variedad de familias de robots. Los más utilizados en la industria son los llamados manipuladores seriales y manipuladores paralelos. Los primeros, mucho más utilizados y estudiados que los segundos, especialmente en lo que respecta a su fabricación y su control [1]. Sin embargo, esta configuración en serie supone también una pérdida de dinamismo: cada accionamiento tiene que llevar el peso de los accionamientos que le siguen. Son configuraciones con grandes masas en movimiento, por lo que resulta complicado obtener velocidades altas de trabajo. En los últimos años se ha presentado un creciente interés de los investigadores en los manipuladores paralelos debido a sus ventajas sobre sus contrapartes seriales, esto se debe a que sin importar que los manipuladores paralelos tengan actuadores fijos en su estructura, o que se muevan muy próximos a ella, ninguno de los actuadores debe llevar el peso de otro cuando realiza un movimiento, todos ellos conectan la estructura fija con el cabezal de trabajo o la herramienta final. Por estas características las cadenas cinemáticas y los sistemas de accionamiento pueden ser más pequeños, lo que permite aumentar la masa útil que se puede mover con el manipulador [2]