Open Access
VTOL UAV digital twin for take-off, hovering and landing in different wind conditions
(Elsevier, 2023) Aláez Gómez, Daniel; Olaz Moratinos, Xabier; Prieto Míguez, Manuel; Villadangos Alonso, Jesús; Astrain Escola, José Javier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
With UAVs becoming increasingly popular in the industry, vertical take-off and landing (VTOL) convertiplanes are emerging as a compromise between the advantages of planes and multicopters. Due to their large wing surface area, VTOL convertiplanes are subject to a strong wind dependence on critical phases such as take-off, landing, and hovering. Developing a new and improved unmanned aerial vehicle (UAV) is often expensive and associated with failures and accidents. This paper proposes the dynamic characterization of a commercial VTOL convertiplane UAV in copter mode and provides a novel method to estimate the aerodynamic forces and moments for any possible wind speed and direction. Starting from Euler’s equations of rigid body dynamics, we have derived the mathematical formulation to precisely consider aerodynamic forces and moments caused by any wind speed and direction. This unique approach will allow for VTOL convertiplane UAVs to be trained and tested digitally in takeoff, hovering, and landing maneuvers without the cost and hassle of physical testing, and the dependence on existing wind conditions. A digital twin of a VTOL convertiplane UAV in copter mode has been modeled and tested in the Gazebo robotics simulator. Take-off, hovering and landing maneuvers have been compared with and without the wind physics model. Finally, the simulator has been tested against real flight conditions (reproducing the mean wind speed and direction only), showing a natural and realistic behavior.
Embargo
Controlador neuronal basado en aprendizaje por refuerzo para el despegue y aterrizaje autónomo de drones en entornos con viento variable
(2025) Olaz Moratinos, Xabier; Villadangos Alonso, Jesús; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
El control autónomo de drones en condiciones de viento variable representa un desafío crucial en los campos de la aeronáutica y la robótica. En esta tesis, se presenta el diseño y la evaluación de un controlador neuronal basado en aprendizaje por refuerzo (RL), orientado a optimizar la maniobrabilidad autónoma durante las fases críticas de despegue y aterrizaje en entornos complejos. El objetivo principal es superar las limitaciones de los controladores PID tradicionales, mejorando la estabilidad y la precisión del vuelo. Para validar estos avances, se realizarán pruebas exhaustivas mediante simulaciones Hardware-in-the-Loop (HIL), estableciendo comparaciones detalladas con el desempeño de los controladores PID. El aprendizaje por refuerzo (RL - Reinforcement Learning) ha emergido como una solución innovadora para sistemas complejos, permitiendo a los agentes desarrollar políticas óptimas de control a partir de la interacción directa con su entorno, sin requerir modelos precisos del sistema. Este enfoque se destaca por su adaptabilidad y su capacidad para gestionar no linealidades en la dinámica de vuelo de los drones, superando así limitaciones de los métodos convencionales. En este trabajo, el RL se implementa progresivamente en controladores neuronales profundos: desde algoritmos en espacios de acción discretos como Deep Q-Network (DQN) hasta soluciones definitivas en entornos continuos mediante Deep Deterministic Policy Gradient (DDPG) y Proximal Policy Optimization (PPO), integrando simulaciones de entornos realistas que modelan dispositivos y fuerzas externas, incluyendo efectos de viento. Una de las contribuciones clave es el desarrollo de una arquitectura de red neuronal con un Módulo de Adaptación y un Módulo de Conversión, que transforman las fuerzas y momentos en velocidades de motor. Esta innovación permite al controlador neuronal responder a ráfagas de viento de hasta 10 m/s, optimizando a su vez la previsibilidad y confiabilidad mediante una discretización de acciones, lo cual reduce tanto la cantidad de acciones necesarias como el error de posición durante maniobras. Los resultados de las pruebas muestran mejoras notables en estabilidad y precisión de trayectoria, así como en la capacidad de respuesta ante variaciones de viento abruptas. Durante las pruebas, el controlador permitió al modelo 3DR Iris+ mantener la estabilidad en situaciones de viento de hasta 10 m/s (91%de su velocidad máxima) en maniobras de despegue y aterrizaje, obteniendo un rendimiento competitivo con drones avanzados en resistencia relativa. Las pruebas con Hardware-in-the-Loop (HIL) también validaron la eficacia del controlador en entornos físicos, comparándolo contra sistemas PID. Los hallazgos indican que el enfoque propuesto no solo ofrece una solución robusta y eficiente para el control autónomo de drones, sino que además abre nuevas oportunidades para aplicaciones seguras en áreas críticas como vigilancia, rescate y logística. Esta tesis aporta significativamente al campo del control autónomo de UAVs, estableciendo una base sólida para futuros desarrollos en controladores adaptativos inteligentes y en el estudio del vuelo en condiciones ambientales adversas.
Open Access
Demonstration of XRStudio tools for creation of room-size immersive experiences within an extended reality environment
(Association for Computing Machinery, 2023) Ardaiz Villanueva, Óscar; Olaz Moratinos, Xabier; Benbelkheir Núñez, Youssef; Lerga Armendáriz, Álvaro; Gasco González, Lucas; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC
Immersive experiences are mostly created with desktop-based tools using flat displays, mouse and keyboard; as a result immersive experiences have a 2D look and interaction: user sit or stand looking forward, and interact with elements within reach of their arms as in a desktop. The objective of this work is to facilitate creating room-size immersive experiences that take advantage of tethered head mounted displays and hand-held controllers to create while walking freely in space with full body movement freedom. To this end we propose XRStudio, a set of tools that permit to create within an extended reality environment so that authors can walk to move objects in space or manipulate elements with hand and full body movements as in the real world.
Open Access
An interdisciplinary design of an interactive cultural heritage visit for in-situ, mixed reality and affective experiences
(MDPI, 2022) Olaz Moratinos, Xabier; García Marreros, Ricardo M.; Ortiz Nicolás, Amalia; Marichalar Baraibar, Sebastian Roberto; Villadangos Alonso, Jesús; Ardaiz Villanueva, Óscar; Marzo Pérez, Asier; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua
Interactive technologies, such as mixed-reality and natural interactions with avatars, can enhance cultural heritage and the experience of visiting a museum. In this paper, we present the design rationale of an interactive experience for a cultural heritage place in the church of Roncesvalles at the beginning of Camino de Santiago. We followed a participatory design with a multidisciplinary team which resulted in the design of a spatial augmented reality system that employs 3D projection mapping and a conversational agent acting as the storyteller. Multiple features were identified as desirable for an interactive experience: interdisciplinary design team; in-situ; mixed reality; interactive digital storytelling; avatar; tangible objects; gestures; emotions and groups. The findings from a workshop are presented for guiding other interactive cultural heritage experiences. © 2022 by the authors.
Open Access
Mid-air contactless haptics to augment VR experiences
(Association for Computing Machinery, 2023) Ezcurdia Aguirre, Íñigo Fermín; Fernández Ortega, Unai Javier; Olaz Moratinos, Xabier; Marzo Pérez, Asier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC
We present four technologies to deliver contactless haptic stimuli for enriching Virtual Reality (VR) experiences. The technologies are electrostatic piloerection, focused light-induced heat, electric plasma, and ultrasound; the user does not require to wear or touch any device. We describe the working principle behind each technology and how these technologies can provide new exciting sensations in VR experiences. Additionally, we showcase a VR demo experience gathering all four remote haptic stimuli along a circuit for the users to experiment with these new sensations.
Open Access
Quadcopter neural controller for take-off and landing in windy environments
(Elsevier, 2023-09-01) Olaz Moratinos, Xabier; Aláez Gómez, Daniel; Prieto Míguez, Manuel; Villadangos Alonso, Jesús; Astrain Escola, José Javier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC
This paper proposes the design of a quadcopter neural controller based on Reinforcement Learning (RL) for controlling the complete maneuvers of landing and take-off, even in variable windy conditions. To facilitate RL training, a wind model is designed, and two RL algorithms, Deep Deterministic Policy Gradient (DDPG) and Proximal Policy Optimization (PPO), are adapted and compared. The first phases of the learning process consider extended exploration states as a warm-up, and a novel neural network controller architecture is proposed with the addition of an adaptation layer. The neural network’s output is defined as the forces and momentum desired for the UAV, and the adaptation layer transforms forces and momentum into motor velocities. By decoupling attitude from motor velocities, the adaptation layer enhances a more straightforward interpretation of the neural network output and helps refine the rewards. The successful neural controller training has been tested up to 36 km/h wind speed.
Open Access
HIL flight simulator for VTOL-UAV pilot training using X-plane
(MDPI, 2022) Aláez Gómez, Daniel; Olaz Moratinos, Xabier; Prieto Míguez, Manuel; Porcellinis Pascau, Pablo de; Villadangos Alonso, Jesús; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC
With the increasing popularity of vertical take-off and landing unmanned aerial vehicles (VTOL UAVs), a new problem arises: pilot training. Most conventional pilot training simulators are designed for full-scale aircrafts, while most UAV simulators are just focused on conceptual testing and design validation. The X-Plane flight simulator was extended to include new functionalities such as complex wind dynamics, ground effect, and accurate real-time weather. A commercial HIL flight controller was coupled with a VTOL convertiplane UAV model to provide realistic flight control. A real flight case scenario was tested in simulation to show the importance of including an accurate wind model. The result is a complete simulation environment that has been successfully deployed for pilot training of the Marvin aircraft manufactured by FuVeX.