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 paper addresses the kinematic structure and workspace analysis of a parallel manipulator with linear actuators considering two studies.The first one was based on a morphological synthesis in which a kinematic connections approach was implemented. The set of combinations of joints and links for the desired system and their linkage are illustrated. Finally, the development regarding the conceivable morphologyis detailed, providing three linear degrees of freedom between the mobile and fixed platforms. The second study presented the dimensional synthesis of the manipulator, considering a workspace required and an input transmission index. The geometrical design was based on the maximum inscribed workspace volume; the cylindrical shape radius inscribed on a workspace intersection is also exemplified. The geometric determination of the workspace for the manipulator was demonstrated using computer-aided design. A design result of the Delta as checked with the stiffness and condition indices.

La fatiga por fretting es un fenómeno que se presenta cuando dos superficies en contacto están sometidas a cargas normales y tangenciales cíclicas, acompañadas de desplazamientos relativos de baja amplitud. Este mecanismo puede reducir significativamente la vida útil de componentes mecánicos críticos, tales como uniones pernadas, álabes de turbinas y cables metálicos. La complejidad en su caracterización radica en la fuerte dependencia de múltiples variables, entre las cuales el coeficiente de fricción desempeña un papel fundamental debido a su evolución durante el proceso de fatiga. En particular, aunque el efecto de coeficientes de fricción elevados ha sido estudiado, existe una limitada comprensión del impacto de valores bajos, típicos de las etapas iniciales del contacto. En este trabajo se analiza la influencia del coeficiente de fricción sobre la nucleación de grietas mediante un modelo numérico por elementos finitos de tipo cilindro-plano. Para la evaluación del daño se emplean dos criterios de plano crítico: el parámetro de Fatemi-Socie y el criterio de Findley. El coeficiente de fricción se hace variar en el rango 0.36-0.84, representando estados intermedios entre condiciones iniciales y estabilizadas. Los esfuerzos obtenidos del modelo son procesados mediante un algoritmo de postproceso que permite calcular los parámetros de daño y estimar la vida de nucleación de grieta. Los resultados evidencian una disminución sistemática de la vida de nucleación con el incremento del coeficiente de fricción, así como una predicción conservadora de ambos criterios. No obstante, la sensibilidad de la vida de nucleación disminuye a medida que el coeficiente de fricción aumenta. Por otra parte, la localización y orientación de la grieta no presentan variaciones significativas dentro del rango analizado. Los resultados obtenidos aportan elementos relevantes para la modelación y el diseño de sistemas mecánicos, particularmente en la selección de parámetros de contacto y en la predicción de vida de fatiga en condiciones variables de fricción.

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.

This work presents a real-time, explainable Eye-to-Hand visual-feedback architecture for trajectory control of a planar 2RRR parallel manipulator. A fine-tuned YOLOv8n detector locates an end-effector marker, a calibrated homography converts image coordinates into Cartesian position, and the resulting visual error feeds a Cartesian PID correction before inverse kinematics generates the actuator commands. A previously validated ROS/Gazebo digital twin supplies reference trajectories, while the Dynamixel MX-64 encoders are retained only as an independent measurement source for training, calibration, and experimental validation. On 3,142 test images, the observer achieved a position RMSE of 3.455 mm (MAE = 2.804 mm). Wilcoxon tests detected no significant median offset on either Cartesian axis, although confidence intervals for the arithmetic mean differences excluded zero and indicate small mean offsets. The camera-in-the-loop controller was evaluated in 12 physical runs covering four trajectories; whole-trajectory errors ranged from 1.48 to 2.57 mm RMSE, with a pooled RMSE of 1.78 mm and a maximum error of 4.52 mm. Grad-CAM, LIME, and SHAP concentrated their attribution on the end-effector marker during successful detections and lost spatial agreement under synthetic occlusion. The framework combines real-time visual correction, independent encoder-based validation, digital-twin-assisted experimentation, and explainable perception. Physical validation was performed on the Dynamixel-equipped prototype; operation with actuators lacking joint-state telemetry remains to be investigated.

This work presents the kinetics and kinematics analysis for delta-3 parallel manipulator. Kinematics and Kinetics validation was performed with a virtual prototype cosimulation using Solidworks and Labview and considering experimental data from physical prototype testing. In respect to the same testing path, comparisons of kinematics results from physical prototype against data of both virtual prototype and theoretical model, corroborate that positions of mobile platform have similar values in respect to the global coordinate system. On the other hand, actuator torques of theoretical model and virtual prototype reported conservative behaviors, whereas the torque of the physical prototype presents lower requirements under the same conditions. Work in unison of these computational tools allows a coherent study of mechanical systems and a direct comparison of the theoretical model, physical prototype and virtual prototype.