17 research outputs found
RF-Based Location Using Interpolation Functions to Reduce Fingerprint Mapping
Indoor RF-based localization using fingerprint mapping requires an initial training step, which represents a time consuming process. This location methodology needs a database conformed with RSSI (Radio Signal Strength Indicator) measures from the communication transceivers taken at specific locations within the localization area. But, the real world localization environment is dynamic and it is necessary to rebuild the fingerprint database when some environmental changes are made. This paper explores the use of different interpolation functions to complete the fingerprint mapping needed to achieve the sought accuracy, thereby reducing the effort in the training step. Also, different distributions of test maps and reference points have been evaluated, showing the validity of this proposal and necessary trade-offs. Results reported show that the same or similar localization accuracy can be achieved even when only 50% of the initial fingerprint reference points are taken
Multi-Sensor Localization and Navigation for Remote Manipulation in Smoky Areas
Abstract When localizing mobile sensors and actuators in
indoor environments laser meters, ultrasonic meters or
even image processing techniques are usually used. On
the other hand, in smoky conditions, due to a fire or
building collapse, once the smoke or dust density grows,
optical methods are not efficient anymore. In these
scenarios other type of sensors must be used, such as
sonar, radar or radiofrequency signals. Indoor
localization in low‐visibility conditions due to smoke is
one of the EU GUARDIANS [1] project goals.
The developed method aims to position a robot in front
of doors, fire extinguishers and other points of interest
with enough accuracy to allow a human operator to
manipulate the robot’s arm in order to actuate over the
element. In coarse‐grain localization, a fingerprinting
technique based on ZigBee and WiFi signals is used,
allowing the robot to navigate inside the building in
order to get near the point of interest that requires
manipulation. In fine‐grained localization a remotely
controlled programmable high intensity LED panel is
used, which acts as a reference to the system in smoky
conditions. Then, smoke detection and visual fine‐
grained localization are used to position the robot with
precisely in the manipulation point (e.g., doors, valves,
etc.)
Underwater Multirobot Cooperative Intervention MAC Protocol
This work introduces a Medium Access Control (MAC) protocol designed to allow a group of underwater robots that share a wireless communication channel to effectively communicate with each other. The goal of the Underwater Multirobot Cooperative Intervention MAC (UMCI-MAC) protocol presented in this work is to minimize the end to end delay and the jitter. The access to the medium in UMCI-MAC follows a Time Division Multiple Access (TDMA) strategy which is arbitrated by a master, which also has the capability to prioritize the transmission of some nodes over the rest of the network. Two experiments have been carried out with a team of four Autonomous Underwater Vehicles (AUV) in order to compare this protocol with Aloha-CS and S-FAMA MAC protocols used in Underwater Wireless Sensor Networks (UWSN). In the first experiment, the communications and the AUVs have been simulated using UWSim-NET. The objective of this experiment was to evaluate all three protocols in terms of delay, jitter, efficiency, collisions and throughput depending on the size of the data packet and the rate of packet delivery in the application layer for each robot. The results of this experiment proved that UMCI-MAC successfully avoids packet collisions and outperforms the other two protocols in terms of delay, jitter and efficiency. The second experiment consisted of a Hardware In The Loop (HIL) teleoperation of a team of four robots. One of the AUVs was a real BlueROV in a water tank, while the remaining AUVs and the communications were simulated with UWSim-NET. It demonstrates the impact of the MAC protocols in underwater acoustic links. Of the three MAC protocols evaluated in this work, UMCI-MAC was the only one which succeeded in the proposed teleoperation experiment. Thus demonstrating its suitability as a communications protocol in underwater cooperative robotics
A visually-guided position control method, in underwater conditions, using an inexpensive remotely operated vehicle
Ponència presentada a 9th Martech International Workshop on Marine Technology (MARTECH 2021), Vigo, 16-18 juny, 202
CompaRob: the shopping cart assistance robot
Technology has recently been developed which offers an excellent opportunity to design systems with the ability to help people
in their own houses. In particular, assisting elderly people in their environments is something that can significantly improve their
quality of life. However, helping elderly people outside their usual environment is also necessary, to help them to carry out daily
tasks like shopping. In this paper we present a person-following shopping cart assistance robot, capable of helping elderly people
to carry products in a supermarket. First of all, the paper presents a survey of related systems that perform this task, using different
approaches, such as attachable modules and computer vision. After that, the paper describes in detail the proposed system and its
main features. The cart uses ultrasonic sensors and radio signals to provide a simple and effective person localization and following
method. Moreover, the cart can be connected to a portable device like a smartphone or tablet, thus providing ease of use to the end
user. The prototype has been tested in a grocery store, while simulations have been done to analyse its scalability in larger spaces
where multiple robots could coexist.This work was partly supported by Spanish Ministry under Grant DPI2014-57746-C3 (MERBOTS Project) and by Universitat Jaume I Grants P1-1B2015-68 and PID2010-12
Utilizando Arduino Due en la docencia de la entrada/salida
Resumen:
La problemática de la entrada/salida y su gestión suele
formar parte de las asignaturas de introducción a la arquitectura
de computadores. La propia naturaleza del
tema y su diversidad hace que las sesiones prácticas
se lleven a cabo habitualmente, bien sobre dispositivos
específicos sencillos, bien sobre simuladores, lo que
las aleja de los dispositivos reales y les resta vistosidad.
Sin embargo, es posible utilizar dispositivos actuales y
sencillos, como las tarjetas Arduino, para presentar a
los estudiantes una visión más real y atractiva de la entrada/
salida, manteniendo a su vez la sencillez de uso
de los entornos y sistemas empleados, lo que consideramos
prioritario en los primeros cursos de grado.
En nuestro caso, puesto que actualmente fundamentamos
nuestra docencia en arquitectura de computadores
sobre la arquitectura ARM, hemos optado por el modelo
Arduino Due, que dispone de un microcontrolador,
el ATSAM3X8E, que implementa la versión Cortex-
M3 de la arquitectura ARM.
Para poder realizar las prácticas de entrada/salida hemos
modificado ligeramente el entorno Arduino para
poder incluir programas en ensamblador, y hemos diseñado
una pequeña tarjeta con un led RGB y un pulsador,
lo que ha permitido proponer ejercicios sencillos
pero vistosos. Los propios dispositivos del microcontrolador
de la Arduino DUE han bastado para abarcar
otros aspectos de la entrada/salida y presentar ejemplos
de mayor complejidad para incentivar a los estudiantes.
La primera experiencia con este entorno ha sido satisfactoria
tanto para el profesorado de las asignaturas en
las que se ha utilizado como para los estudiantes, en
quienes además se ha fomentado el interés en continuar
trabajando con las tarjetas Arduino en sus propios
proyectos.Abstract:
The input/output (I/O) and its management is often part
of the introductory courses to computer architecture.
The very nature of this topic and its diversity makes
that the practice sessions often take place either on simple
specific devices, or on simulators, which hide the
complexity of actual I/O devices and subtracts their appealing.
However, it is possible to use today existing and simple
devices such as Arduino boards to introduce students
to a more realistic and attractive vision of the I/O,
while maintaining the ease of use of the required environments
and systems, which we consider a priority on
first degree courses.
In our case, since currently we base our teaching on
computer architecture on the ARM architecture, we
have opted for the Arduino Due model, which has a
microcontroller, ATSAM3X8E, which implements the
Cortex-M3 version of the ARM Architecture.
To carry out the laboratory sessions on I/O we have
slightly modified the Arduino IDE in order to accept
assembly source code. In addition, we have designed
and built a small board with an RGB led and a switch,
which allowed us to propose simple but colourful exercises.
The built-in I/O included in the ARM controller
of the Arduino DUE board have proved enough to explore
other important aspects of I/O as well as to offer
more complex examples to incentivate the students on
the subject.
The first experience with this environment has been
satisfactory for both teachers and students, who also
have fostered interest in continuing to work with Arduino
cards in their own projects
Underwater radio frequency image sensor using progressive image compression and region of interest
The increasing demand for underwater robotic intervention systems around the world in several application domains requires more versatile and inexpensive systems. By using a wireless communication system, supervised semi-autonomous robots have freedom of movement; however, the limited and varying bandwidth of underwater radio frequency (RF) channels is a major obstacle for the operator to get camera feedback and supervise the intervention. This paper proposes the use of progressive (embedded) image compression and region of interest (ROI) for the design of an underwater image sensor to be installed in an autonomous underwater vehicle, specially when there are constraints on the available bandwidth, allowing a more agile data exchange between the vehicle and a human operator supervising the underwater intervention. The operator can dynamically decide the size, quality, frame rate, or resolution of the received images so that the available bandwidth is utilized to its fullest potential and with the required minimum latency. The paper focuses first on the description of the system, which uses a camera, an embedded Linux system, and an RF emitter installed in an OpenROV housing cylinder. The RF receiver is connected to a computer on the user side, which controls the camera monitoring parameters, including the compression inputs, such as region of interest (ROI), size of the image, and frame rate. The paper focuses on the compression subsystem and does not attempt to improve the communications physical media for better underwater RF links. Instead, it proposes a unified system that uses well-integrated modules (compression and transmission) to provide the scientific community with a higher-level protocol for image compression and transmission in sub-sea robotic interventions
Further teleoperated experiments with an underwater mobile manipulator via acoustic modem: modem characterization
In this study, we conducted preliminary experiments to characterize an acoustic sonar [1][2] for underwater communication. We carried on image transmission experiments and attempted to reduce reflections using insulating cork. Moving the buoy along the surface revealed the central area of the tank to have the best communication with Girona. We plan to conduct further experiments with the acoustic modem in a realistic environment. In addition, we are also testing Visible Light Communication (VLC) [3] optical modems, which yielded better results than the acoustic modem. We aim to develop a multimodal system for improved communication under different environmental conditions.Peer Reviewe
Introducción a la arquitectura de computadores con QtARMSim y Arduino
Codi d’assignatura EI1004 / MT100