Carvajal, Christian
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Carvajal, Christian
Main Affiliation
Ambato

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Technology-Mediated Collaborative Strategies Among Online University Students

2025 , Núñez-Naranjo, Aracelly Fernanda , Quezada-Sarmiento, Pablo Alejandro , Junta, Christian , Orly Carvache-Franco , Lidia Minchenkova , Carvajal, Christian

This quasi-experimental study aimed to evaluate the effectiveness of collaborative teaching strategies mediated by digital technologies among online university students. The research was conducted with a sample of 256 participants, divided into an experimental group and a control group. While both groups used technological resources, only the experimental group engaged in structured collaborative strategies using tools such as Genially, Kahoot, Canva, Padlet, and Wordwall, within the framework of the Cátedra Integradora course. The results revealed a significant improvement in the academic performance of the experimental group, with an average increase of 27.4%, compared to 13.2% in the control group. Furthermore, the teacher's perception highlighted higher levels of student engagement, motivation, and collaboration among those who actively participated in the strategies. These findings demonstrate that the intentional use of educational technologies with a collaborative focus fosters active, participatory, and meaningful learning, while also strengthening socio-emotional skills and improving academic achievement in virtual higher education settings. © 2025 IEEE.

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Digital Twin Integration for Active Learning in Robotic Manipulator Control Within Engineering 4.0

2025 , Fernando J. Pantusin , Jessica S. Ortiz , Carvajal, Christian , Víctor H. Andaluz , Lenin G. Yar , Flavio Roberti , Daniel Gandolfo

Robotic systems play an increasingly significant role in both education and industry; however, access to physical robots remains a challenge due to high costs and operational risks. This work presents a training platform based on Digital Twins, aimed at active learning in the control of robotic manipulators, with a focus on the UFACTORY 850 arm. The proposed approach integrates mathematical modeling, interactive simulation, and experimental validation, enabling the implementation and testing of control strategies in three virtual scenarios that replicate real-world conditions: a laboratory, a service environment, and an industrial production line. The system relies on kinematic and dynamic models of the manipulator, using maneuverability velocities as input signals, and employs ROS as middleware to link the Unity 2022.2.14 graphics engine with the control algorithms developed in MATLAB R2022a. Experimental results demonstrate the accuracy of the implemented models and the effectiveness of the control algorithms, validating the usefulness of Digital Twins as a pedagogical tool to support safe, accessible, and innovative learning in robotic engineering.

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Experimental Validation of a Kinematic Control Strategy for Trajectory Tracking in Quadruped Robots

2025 , Carvajal, Christian , Varela Aldas, José , Víctor H. Andaluz , Chicaiza Claudio, Fernando , Ayala-Chauvin, Manuel Ignacio

This work presents a high-level control architecture for trajectory tracking in quadruped robots. The proposed controller is based on the motion kinematics of the robot's center of mass (CoM). The proposed strategy transforms planned trajectories in Cartesian space into motion velocity commands for the robot, using a differential kinematic model that relates the velocity of the robot's operational point to its velocity in the XY-plane. The control scheme is organized hierarchically, where the kinematic controller operates independently from the system dynamics, which are handled by low-level controllers. The proposed control architecture is experimentally validated using the Unitree Go2 quadruped robot, employing MATLAB and ROS2 tools. The results confirm the feasibility of using purely kinematic models for high-level locomotion task control under real-world operating conditions. © 2025 IEEE.

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A Hardware‐in‐the‐Loop and 3D Simulation Framework for Active Learning in Engineering Education

2025 , Jessica S. Ortiz , Manuel A. Masapanta , Víctor H. Andaluz , Carvajal, Christian

This paper describes the implementation of an industrial control system using the Hardware‐in‐the‐Loop (HIL) technique, integrating a Siemens S7‐1200 PLC with a virtual plant developed in Unity 3D, using the Modbus TCP communication protocol. This integration allows real‐time simulation of industrial processes in a safe, immersive and interactive environment, facilitating the design, testing and validation of control strategies without the need for a physical plant. As part of the study, usability tests were carried out to verify whether the proposed solution is suitable for use as a teaching resource by engineering students. The evaluation was applied to two groups of 20 students each, who interacted with the virtual environment and executed control and monitoring tasks of the simulated process. The results obtained show a satisfactory acceptance of the platform, highlighting its usefulness as a support tool for the understanding and manipulation of automated processes in a controlled environment. This approach proves to be an efficient, safe and scalable alternative for training in industrial automation, aligned with the principles of Industry 4.0.

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Virtual Teleoperation System for Mobile Manipulator Robots Focused on Object Transport and Manipulation

2024 , Fernando J. Pantusin , Carvajal, Christian , Jessica S. Ortiz , Víctor H. Andaluz

This work describes the development of a tool for the teleoperation of robots. The tool is developed in a virtual environment using the Unity graphics engine. For the development of the application, a kinematic model and a dynamic model of a mobile manipulator are used. The mobile manipulator robot consists of an omnidirectional platform and an anthropomorphic robotic arm with 4 degrees of freedom (4DOF). The model is essential to emulate the movements of the robot and to facilitate the immersion in the virtual environment. In addition, the control algorithms are established and developed in MATLAB 2020 software, which improves the acquisition of knowledge to teleoperate robots and execute tasks of manipulation and transport of objects. This methodology offers a cheaper and safer alternative to real physical systems, as it reduces both the costs and risks associated with using a real robot for training.

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Bilateral Rate/Position Delayed Teleoperation Control for UAVs: A Performance Evaluation

2025 , Chicaiza Claudio, Fernando , Emanuel Slawiñski , Viviana Moya , Carvajal, Christian , Varela Aldas, José , Ayala-Chauvin, Manuel Ignacio

This paper introduces a bilateral teleoperation system for UAVs that employs a hybrid control scheme combining rate and non-linear position modes. By continuously switching between these modes, the system achieves both agile manoeuvring and precise positioning under communication delays. Validation is carried out using a dynamic model for the master robot with a Novint Falcon haptic device and a simplified model for the slave robot in Gazebo-ROS2. Performance metrics including task completion time, mean squared error, and force feedback demonstrate enhanced stability and efficiency, suggesting promising applications in inspection, environmental monitoring and search and rescue

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