Vision-based localization of an underwater robot in a structured environment

This paper presents a vision-based localization approach for an underwater robot in a structured environment. The system is based on a coded pattern placed on the bottom of a water tank and an onboard down looking camera. Main features are, absolute and map-based localization, landmark detection and tracking, and real-time computation (12.5 Hz). The proposed system provides three-dimensional position and orientation of the vehicle along with its velocity. Accuracy of the drift-free estimates is very high, allowing them to be used as feedback measures of a velocity-based low-level controller. The paper details the localization algorithm, by showing some graphical results, and the accuracy of the system

Dam wall detection and tracking using a Mechanically Scanned Imaging Sonar

In dam inspection tasks, an underwater robot has to grab images while surveying the wall meanwhile maintaining a certain distance and relative orientation. This paper proposes the use of an MSIS (mechanically scanned imaging sonar) for relative positioning of a robot with respect to the wall. An imaging sonar gathers polar image scans from which depth images (range & bearing) are generated. Depth scans are first processed to extract a line corresponding to the wall (with the Hough transform), which is then tracked by means of an EKF (Extended Kalman Filter) using a static motion model and an implicit measurement equation associating the sensed points to the candidate line. The line estimate is referenced to the robot fixed frame and represented in polar coordinates (rho&thetas) which directly corresponds to the actual distance and relative orientation of the robot with respect to the wall. The proposed system has been tested in simulation as well as in water tank conditions

Knowledge integration within an applied mobile robot summer course

This paper presents the use of a mobile robot platform as an innovative educational tool in order to promote and integrate different curriculum knowledge. Hence, it is presented the acquired experience within a summer course named ldquoapplied mobile roboticsrdquo. The main aim of the course is to integrate different subjects as electronics, programming, architecture, perception systems, communications, control and trajectory planning by using the educational open mobile robot platform PRIM. The summer course is addressed to a wide range of student profiles. However, it is of special interests to the students of electrical and computer engineering around their final academic year. The summer course consists of the theoretical and laboratory sessions, related to the following topics: design & programming of electronic devices, modelling and control systems, trajectory planning and control, and computer vision systems. Therefore, the clues for achieving a renewed path of progress in robotics are the integration of several knowledgeable fields, such as computing, communications, and control sciences, in order to perform a higher level reasoning and use decision tools with strong theoretical base

Neptune: a hil simulator for multiple UUVs

This paper overviews the field of graphical simulators used for AUV development, presents the taxonomy of these applications and proposes a classification. It also presents Neptune, a multivehicle, real-time, graphical simulator based on OpenGL that allows hardware in the loop simulations

Graphical simulators for AUV development

A long development time is needed from the design to the implementation of an AUV. During the first steps, simulation plays an important role, since it allows for the development of preliminary versions of the control system to be integrated. Once the robot is ready, the control systems are implemented, tuned and tested. The use of a real-time simulator can help closing the gap between off-line simulation and real testing using the already implemented robot. When properly interfaced with the robot hardware, a real-time graphical simulation with a "hardware in the loop" configuration, can allow for the testing of the implemented control system running in the actual robot hardware. Hence, the development time is drastically reduced. These paper overviews the field of graphical simulators used for AUV development proposing a classification. It also presents NEPTUNE, a multi-vehicle, real-time, graphical simulator based on OpenGL that allows hardware in the loop simulations

Abstracting qualitative information for process supervision

Supervisory systems evolution makes the obtaining of significant information from processes more important in the way that the supervision systems' particular tasks are simplified. So, having signal treatment tools capable of obtaining elaborate information from the process data is important. In this paper, a tool that obtains qualitative data about the trends and oscillation of signals is presented. An application of this tool is presented as well. In this case, the tool, implemented in a computer-aided control systems design (CACSD) environment, is used in order to give to an expert system for fault detection in a laboratory plant

Programació del robot e-puck amb Microsoft Robotics Studio

Microsoft Robotics Studio (MRS) és un entorn per a crear aplicacions per a robots utilitzant una gran varietat de plataformes hardware. Conté un entorn de simulació en el que es pot modelar i simular el moviment del robot. Permet també programar el robot, i executar-lo en l’entorn simulat o bé en el real. MRS resol la comunicació entre elsdiferents processos asíncrons que solen estar presents en el software de control d’unrobot: processos per atendre sensors, actuadors, sistemes de control, comunicacions amb l’exterior,... MRS es pot utilitzar per modelar nous robots utilitzant components que ja estiguin disponibles en les seves llibreries, o també permet crear component nous. Per tal de conèixer en detall aquesta eina, seria interessant utilitzar-la per programa els robots e-pucks, uns robots mòbils autònoms de petites dimensions que disposen de dos motors i un complet conjunt de sensors. El que es vol és simular-los, realitzar un programa de control, realitzar la interfície amb el robot i comprovar el funcionament amb el robot real

Disseny d’un comportament en ROS per a mantenir la posició d’un vehicle autònom submarí a partir de referències visuals

En el Centre d'Investigació en Robòtica Submarina (CIRS) de la Universitat de Gironaes disposa de diferents robots submarins els quals utilitzen una arquitectura software anomenada Component Oriented Layered-based Architecture for Autonomy ( COLA2 ), la qual ha estat desenvolupada per estudiants i professors del mateix centre. Per tal de fer aquesta arquitectura més accessible per a professors i estudiant d’altres centres la COLA2 s’està adaptant al Robot Operative System (ROS) que és un framework genèricper al desenvolupament d’aplicacions amb robots. Aquest projecte pretén dissenyar un comportament per al robot Girona500 que estigui desenvolupat dins la versió ROS de l’arquitectura COLA2. El comportament haurà de fer mantenir una determinada posició al robot amb informació visual de la càmera del robot i amb dades de navegació. La tasca de mantenir la posició es de vital importància per a poder realitzar intervencions submarines que requereixen de precisió i, precisament, el medi on es treballa no ajuda

Sistema de manteniment de l'equilibri per a un robot bípede

Dins el departament d’Electrònica, Informàtica i Automàtica de la Universitat de Girona s’handissenyat i construït dues plataformes bípedes per a l’ús docent. La mésevolucionada d’elles, finalitzada l’any 1999, està composada per dues cames d’alumini ambtres actuadors lineals cada una, simulant la funció del turmell, del genoll i del maluc. Els objectius que es pretenen aconseguir amb aquest projecte són molt concrets i tots ellsestan destinats a millorar el funcionament del robot bípede. Aquests objectius són: (1)dissenyar dos graus de llibertat lineals en forma de pla XY per moure el pes que convinguiper assegurar l’equilibri durant el moviment de la plataforma bípede, (2) dissenyar una placaamb una FPGA que generi senyals PWM pels vuit motors disponibles, que llegeixi els dosencoders dels motors del pla XY i que es comuniqui amb un PC equipat amb una tarjad’adquisició de dades específica, (3) dissenyar una placa de potència adequada pel controldels motors, (4) finalment realitzar un programa per comprovar el correcte funcionament deles plaques, dels actuadors i dels sensors utilitzats en la plataforma bípede

Effects of acute versus repeated cocaine exposure on the expression of endocannabinoid signaling-related proteins in the mouse cerebellum.

Growing awareness of cerebellar involvement in addiction is based on the cerebellum's intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid receptor type 1 receptors and enzymes that produce [diacylglycerol lipase alpha/beta (DAGLα/β) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD)] and degrade [monoacylglycerol lipase (MAGL) and fatty acid amino hydrolase (FAAH)] eCB} were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system [glutamate synthesizing enzymes liver-type glutaminase isoform (LGA) and kidney-type glutaminase isoform (KGA), metabotropic glutamatergic receptor (mGluR3/5), NMDA-ionotropic glutamatergic receptor (NR1/2A/2B/2C) and AMPA-ionotropic receptor subunits (GluR1/2/3/4)] and the gene expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, because noradrenergic terminals innervate the cerebellar cortex. Results indicated that acute cocaine exposure decreased DAGLα expression, suggesting a down-regulation of 2-arachidonylglycerol (2-AG) production, as well as gene expression of TH, KGA, mGluR3 and all ionotropic receptor subunits analyzed in the cerebellum. The acquisition of conditioned locomotion and sensitization after repeated cocaine exposure were associated with an increased NAPE-PLD/FAAH ratio, suggesting enhanced anandamide production, and a decreased DAGLβ/MAGL ratio, suggesting decreased 2-AG generation. Repeated cocaine also increased LGA gene expression but had no effect on glutamate receptors. These findings indicate that acute cocaine modulates the expression of the eCB and glutamate systems. Repeated cocaine results in normalization of glutamate receptor expression, although sustained changes in eCB is observed. We suggest that cocaine-induced alterations to cerebellar eCB should be considered when analyzing the adaptations imposed by psychostimulants that lead to addiction.

Modelling the Human Values Scale from Consumers Transactional Data Bases

The main objective of this paper aims at developing a methodology that takes into account the human factor extracted from the data base used by the recommender systems, and which allow to resolve the specific problems of prediction and recommendation. In this work, we propose to extract the user's human values scale from the data base of the users, to improve their suitability in open environments, such as the recommender systems. For this purpose, the methodology is applied with the data of the user after interacting with the system. The methodology is exemplified with a case study

Using petri nets to specify and execute missions for autonomous underwater vehicles

This paper presents the design and implementation of a mission control system (MCS) for an autonomous underwater vehicle (AUV) based on Petri nets. In the proposed approach the Petri nets are used to specify as well as to execute the desired autonomous vehicle mission. The mission is easily described using an imperative programming language called mission control language (MCL) that formally describes the mission execution thread. A mission control language compiler (MCL-C) able to automatically translate the MCL into a Petri net is described and a real-time Petri net player that allows to execute the resulting Petri net onboard an AUV are also presented

Estrategia de reducción de costes en la artroplastia total de rodilla

Aim: Assess the clinical utility of plain radiography in the first postoperative outpatient visit after total knee arthroplasty. Patients and Methods: 200 patients which underwent a total knee arthroplasty from January to May 2012 were analyzed retrospectively, they had two previous control radiographs at hospital discharge and two more at 4-6 weeks after surgery, which were compared, seeking for radiographics signs that would induce a therapeutic changes in the patient’s clinical course. Results: No radiographics signs were observed in the cases studied in the first postoperative visit one month after the surgery, consequently the patient’s treatment plan had no change. Discussion: Our results support those of other authors who have recognized the benefits of reducing the number of postoperative radiographs, improve the cost effectiveness of outpatients care and avoid an extra damage to the patient’s health. We believe that repeated use of serial radiographs in outpatient is simply a custom that has become law, to calm down the patient, and his surgeon, with no scientific evidence to support it use. Conclusions: Our results suggest that the plain AP and L radiographic projection at the first visit, one month later after a TKA, does not provide any clinic information, adds substantial cost to the heath-care system and unnecessary harms the patient.

Disseny i implementació d'un sistema de navegació inercial i la seva aplicació a la robòtica mòbil

La UdG desposa de diversos robots mòbils per a finalitats docents i de recerca que utilitzen sistemes de localització incremental mitjançant bàsicament encoders incrementals. Actualment, en el mercat de l’automoció s’ha desenvolupat una sèrie de dispositius electrònics tals com brúixoles electròniques, acceleròmetres, giroscòpics, etc. L’objectiu és dissenyar i construir un sistema de navegació inercial format per un acceleròmetre, un giroscòpic, una brúixola i un microcontrolador encarregat de governar les ordres. El llenguatge utilitzat serà l’assemblador, ja que es pretén una execució molt eficient de les rutines creades. Les dades obtingudes es transmetran a l’ordinador per mitjà del protocol RS-232 i un programa en C emmagatzemarà les dades en un document de text. Aquestes dades seran tractades amb l’entorn MATLAB per tal d’interpretar-les i representar-les gràficament. Per analitzar el funcionament del sistema s’utilitzarà la plataforma PRIM

Dynamic modelling of an underwater vehicle

Nessie is an Autonomous Underwater Vehicle (AUV) created by a team of students in the Heriot Watt University to compete in the Student Autonomous Underwater Competition, Europe (SAUC-E) in August 2006. The main objective of the project is to find the dynamic equation of the robot, dynamic model. With it, the behaviour of the robot will be easier to understand and movement tests will be available by computer without the need of the robot, what is a way to save time, batteries, money and the robot from water inside itself. The object of the second part in this project is setting a control system for Nessie by using the model