Motion planning with dynamics awareness for long reach manipulation in aerial robotic systems with two arms

Human activities in maintenance of industrial plants pose elevated risks as well as significant costs due to the required shutdowns of the facility. An aerial robotic system with two arms for long reach manipulation in cluttered environments is presented to alleviate these constraints. The system consists of a multirotor with a long bar extension that incorporates a lightweight dual arm in the tip. This configuration allows aerial manipulation tasks even in hard-to-reach places. The objective of this work is the development of planning strategies to move the aerial robotic system with two arms for long reach manipulation in a safe and efficient way for both navigation and manipulation tasks. The motion planning problem is addressed considering jointly the aerial platform and the dual arm in order to achieve wider operating conditions. Since there exists a strong dynamical coupling between the multirotor and the dual arm, safety in obstacle avoidance will be assured by introducing dynamics awareness in the operation of the planner. On the other hand, the limited maneuverability of the system emphasizes the importance of energy and time efficiency in the generated trajectories. Accordingly, an adapted version of the optimal Rapidly-exploring Random Tree algorithm has been employed to guarantee their optimality. The resulting motion planning strategy has been evaluated through simulation in two realistic industrial scenarios, a riveting application and a chimney repairing task. To this end, the dynamics of the aerial robotic system with two arms for long reach manipulation has been properly modeled, and a distributed control scheme has been derived to complete the test bed. The satisfactory results of the simulations are presented as a first validation of the proposed approach.Unión Europea H2020-644271Ministerio de Ciencia, Innovación y Universidades DPI2014-59383-C2-1-

High-speed autonomous navigation system for heavy vehicles

This paper presents techniques for GPS based autonomous navigation of heavy vehicles at high speed. The control system has two main functions: vehicle position estimation and generation of the steering commands for the vehicle to follow a given path autonomously. Position estimation is based on fusion of measurements from a carrier-phase differential GPS system and odometric sensors using fuzzy logic. A Takagi-Sugeno fuzzy controller is used for steering commands generation, to cope with different road geometry and vehicle velocity. The presented system has been implemented in a 13 tons truck, and fully tested in very demanding conditions, i.e. high velocity and large curvature variations in paved and unpaved roads

Decentralized 3D Collision Avoidance for Multiple UAVs in Outdoor Environments

The use of multiple aerial vehicles for autonomous missions is turning into commonplace. In many of these applications, the Unmanned Aerial Vehicles (UAVs) have to cooperate and navigate in a shared airspace, becoming 3D collision avoidance a relevant issue. Outdoor scenarios impose additional challenges: (i) accurate positioning systems are costly; (ii) communication can be unreliable or delayed; and (iii) external conditions like wind gusts affect UAVs’ maneuverability. In this paper, we present 3D-SWAP, a decentralized algorithm for 3D collision avoidance with multiple UAVs. 3D-SWAP operates reactively without high computational requirements and allows UAVs to integrate measurements from their local sensors with positions of other teammates within communication range. We tested 3D-SWAP with our team of custom-designed UAVs. First, we used a Software-In-The-Loop simulator for system integration and evaluation. Second, we run field experiments with up to three UAVs in an outdoor scenario with uncontrolled conditions (i.e., noisy positioning systems, wind gusts, etc). We report our results and our procedures for this field experimentation.European Union’s Horizon 2020 research and innovation programme No 731667 (MULTIDRONE

Chiral flow in a binary mixture of two-dimensional active disks

We study, experimentally, the dynamics of a binary mixture of air-fluidized disks. The disks are chiral since they incorporate a set of blades with constant tilt. Both species are identical except for their blades tilt angle, which is rotated by 180o in the second species. We analyze the phase behavior of the system. Our analysis reveals a wide range of different fluid dynamics, including chiral flow. This chiral flow features in its base state a large vortex. We report, for certain ranges of relative particle density of each species, inversion of the vorticity of this vortex. We discuss on the possible mechanisms behind these chiral flow transitions.Comment: Additional data can be found in: https://doi.org/10.5281/zenodo.664770

Threat Management Methodology for Unmanned Aerial Systems operating in the U-space

This paper presents a threat management methodology for Unmanned Aircraft Systems (UAS) operating in the civil airspace. The work is framed within an Unmanned Traffic Management (UTM) system based on the U-space initiative. We propose a new method that focuses on providing the required automated decision-making during real-time threat management and conflict resolution, which is one of the main gaps in the current U-space ecosystem. Our method is capable of handling all commonplace UTM threats, as well as selecting optimal mitigation actions, trading off efficiency and safety. Our implementation is open-source and fully integrated in a UTM software architecture, implementing U-space services related to emergency management and tactical deconfliction. We demonstrate our methodology through a set of realistic use cases with actual UAS operating in civil airspace. For that, we performed field experiments in an aerodrome with segregated airspace, and we showcased that the methodology is capable of autonomously managing heterogeneous threats in real time.Unión Europea - Horizonte 2020 77629

Aprendizaje de trayectorias vía demostraciones para vehículo marino no tripulado

Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)En los últimos años está habiendo un auge importante en el empleo de embarcaciones no tripuladas (USV en su acrónimo anglosajón) para diversas aplicaciones, debido al incremento en la eficiencia y seguridad que pueden aportar. Para ello es necesario que estos vehículos no tripulados puedan desplazarse en el entorno de un puerto de forma segura y cumpliendo con las restricciones que establecen la normativa náutica general y la específica del puerto. En la literatura se han propuesto diversos métodos de planificación, que no garantizan el cumplimiento de las restricciones marcadas por las boyas y otras señalizaciones según dichas normativas. En este artículo se propone una metodología que permite obtener las trayectorias que deben realizarse en diversas maniobras en un puerto mediante el aprendizaje automático de las operaciones realizadas por un patrón con experiencia, de forma que pueda sustituir al sistema de planificación convencional. Los datos empleados para el método de aprendizaje han sido obtenidos experimentalmente mediante pruebas realizadas con el USV Vendaval en el puerto de Ceuta.In recent years there has been an important increase in the use of Unmanned Surface Vessels (USV) for different applications, due to the greater efficiency and safety they can provide. This requires that these unmanned vehicles can navegate safely in a port area and in compliance with the general and port-specific regulations. Various planning methods have been proposed in the literature, which do not guarantee compliance with the restrictions set by buoys and other signaling according to these regulations. This paper proposes a methodology to obtain the trajectories to be performed in various maneuvers in a port by automatic learning the operations performed by an experienced skipper, so that it can replace the conventional planning system. The data used for the learning method have been obtained experimentally through tests carried out with the USV Vendaval in the port of Ceuta.Ministerio de Ciencia e Innovación PID2020- 119027RB-I00Junta de Andalucía, PAIDI 2020 P20 0059

Revision by experts as a strategy for the improvement and validation of LAMS units

After concluding the design of our didactic unit “My First International Congress” in LAMS format and putting it into practice with our students, we intended to improve its didactic possibilities through the execution of an analysis by experts on language teaching. The collection of data on the assessment and perception of the experts of our unit, the analysis of these data and the results confirmed that tools such as LAMS can be quite useful in the teaching of Foreign Languages. However, it also showed that LAMS should provide teachers with devices with which students could work synchronic speaking interaction

Closed-Loop Behavior of an Autonomous Helicopter Equipped with a Robotic Arm for Aerial Manipulation Tasks

This paper is devoted to the control of aerial robots interacting physically with objects in the environment and with other aerial robots. The paper presents a controller for the particular case of a small‐scaled autonomous helicopter equipped with a robotic arm for aerial manipulation. Two types of influences are imposed on the helicopter from a manipulator: coherent and non ‐ coherent influence. In the former case, the forces and torques imposed on the helicopter by the manipulator change with frequencies close to those of the helicopter movement. The paper shows that even small interaction forces imposed on the fuselage periodically in proper phase could yield to low frequency instabilities and oscillations, so called phase circle