Localização de um robô móvel usando odometria e marcos naturais

Several methods of mobile robot navigation request the mensuration of robot position and orientation in its workspace. In the wheeled mobile robot case, techniques based on odometry allow to determine the robot localization by the integration of incremental displacements of its wheels. However, this technique is subject to errors that accumulate with the distance traveled by the robot, making unfeasible its exclusive use. Other methods are based on the detection of natural or artificial landmarks present in the environment and whose location is known. This technique doesnt generate cumulative errors, but it can request a larger processing time than the methods based on odometry. Thus, many methods make use of both techniques, in such a way that the odometry errors are periodically corrected through mensurations obtained from landmarks. Accordding to this approach, this work proposes a hybrid localization system for wheeled mobile robots in indoor environments based on odometry and natural landmarks. The landmarks are straight lines de.ned by the junctions in environments floor, forming a bi-dimensional grid. The landmark detection from digital images is perfomed through the Hough transform. Heuristics are associated with that transform to allow its application in real time. To reduce the search time of landmarks, we propose to map odometry errors in an area of the captured image that possesses high probability of containing the sought mark

Controle dinâmico de robôs móveis com acionamento diferencial

This work addresses the dynamic control problem of two-wheeled differentially driven non-holonomic mobile robot. Strategies for robot positioning control and robot orientating control are presented. Such strategies just require information about the robot con¯guration (x, y and teta), which can be collected by an absolute positioning system. The strategies development is related to a change on the controlled variables for such systems, from x, y and teta to s (denoting the robot linear displacement) and teta, and makes use of the polar coordinates representation for the robot kinematic model. Thus, it is possible to obtain a linear representation for the mobile robot dynamic model and to develop such strategies. It is also presented that such strategies allow the use of linear controllers to solve the control problem. It is shown that there is flexibility to choice the linear controller (P, PI, PID, Model Matching techniques, others) to be implemented. This work presents an introduction to mobile robotics and their characteristics followed by the control strategies development and controllers design. Finally, simulated and experimental results are presented and commented

Sistema de navegação para robôs móveis autônomos

The main task and one of the major mobile robotics problems is its navigation process. Conceptualy, this process means drive the robot from an initial position and orientation to a goal position and orientation, along an admissible path respecting the temporal and velocity constraints. This task must be accomplished by some subtasks like robot localization in the workspace, admissible path planning, trajectory generation and motion control. Moreover, autonomous wheeled mobile robots have kinematics constraints, also called nonholonomic constraints, that impose the robot can not move everywhere freely in its workspace, reducing the number of feasible paths between two distinct positions. This work mainly approaches the path planning and trajectory generation problems applied to wheeled mobile robots acting on a robot soccer environment. The major dificulty in this process is to find a smooth function that respects the imposed robot kinematic constraints. This work proposes a path generation strategy based on parametric polynomials of third degree for the 'x' and 'y' axis. The 'theta' orientation is derived from the 'y' and 'x' relations in such a way that the generated path respects the kinematic constraint. To execute the trajectory, this work also shows a simple control strategy acting on the robot linear and angular velocities

Modelagem linear e identificação do modelo dinâmico de um robô móvel com acionamento diferencial

This work presents a modelling and identification method for a wheeled mobile robot, including the actuator dynamics. Instead of the classic modelling approach, where the robot position coordinates (x,y) are utilized as state variables (resulting in a non linear model), the proposed discrete model is based on the travelled distance increment Delta_l. Thus, the resulting model is linear and time invariant and it can be identified through classical methods such as Recursive Least Mean Squares. This approach has a problem: Delta_l can not be directly measured. In this paper, this problem is solved using an estimate of Delta_l based on a second order polynomial approximation. Experimental data were colected and the proposed method was used to identify the model of a real robot

Controle de posição com restrição à orientação de um Veículo Aéreo Não-Tripulado tipo Quadrirrotor

Quadrotors aircraft are composed by four propellers mounted on four engines on a cross or x disposition, and, in this structure, the engines on the same arm spin in the same direction and the other arm in the opposite direction. By rotating each helix generates vertical upward thrust. The control is done by varying the rotational speed of each motor. Among the advantages of this type of vehicle can cite the mechanical simplicity of construction, the high degree of maneuverability and the ability to have vertical takeoffs and landings. The modeling and control of quadrirrotores have been a challenge due to problems such as nonlinearity and coupling between variables. Several strategies have been developed to control this type of vehicle, from the classical control to modern. There are air surveillance applications where a camera is fixed on the vehicle to point forward, where it is desired that the quadrotor moves at a fixed altitude toward the target also pointing forward, which imposes an artificial constraint motion, because it is not desired that it moves laterally, but only forwards or backwards and around its axes . This restriction is similar to the naturally existing on robots powered by wheels with differential drive, which also can not move laterally, due to the friction of the wheels. Therefore, a position control strategy similar to that used in this type of robot could be adapted for aerial robots like quadrotor. This dissertation presents and discusses some strategies for the control of position and orientation of quadrotors found in the literature and proposes a strategy based on dynamic control of mobile robots with differential drive, called the variable reference control. The validity of the proposed strategy is demonstrated through computer simulations

Desenvolvimento de solução para SLAM utilizando visão de teto

This work intends to show a new and few explored SLAM approach inside the simultaneous localization and mapping problem (SLAM). The purpose is to put a mobile robot to work in an indoor environment. The robot should map the environment and localize itself in the map. The robot used in the tests has an upward camera and encoders on the wheels. The landmarks in this built map are light splotches on the images of the camera caused by luminaries on the ceil. This work develops a solution based on Extended Kalman Filter to the SLAM problem using a developed observation model. Several developed tests and softwares to accomplish the SLAM experiments are shown in details

Espaço e subjetividade: estudo com ribeirinhos

Nesta pesquisa, investigamos as transformações vividas por uma comunidade afetada pela construção de uma usina hidrelétrica no rio Paraná. Utilizando procedimentos da etnografia, realizamos várias visitas à comunidade, reassentada numa vila planejada e construída para substituir a antiga vila que foi submersa. Estabelecemos contatos com os moradores mais antigos e produzimos, com eles, diálogos entabulados em situações diversas, como em visitas às próprias casas e rodas de conversa ocorridas nas calçadas. Nas falas dos ribeirinhos, a mudança do espaço é sentida como algo negativo, em todos os planos da vida. Ressentem-se da perda do rio, da pesca farta, da caça realizada nas matas, das terras férteis cultivadas nas barrancas, da socialidade e de toda produção de subjetividade que mantinham naquele lugar marcado pela proximidade com o rio e suas águas.

Antimicrobial and Cytotoxic Activity of Fruit Extract from Syzygium cumini (L.) Skeels

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Exame microbiológico de sorvetes não pasteurizados

Realizou-se exame microbiológico em 24 amostras de sorvetes não pasteurizados, todos preparados de maneira não industrial e à base de leite (creme, nata, chocolate), fabricados por 12 sorveterias diferentes da cidade de Araraquara, SP. Colheram-se duas amostras de cada sorveteria com intervalo de 15 dias entre as colheitas. Realizaram-se as seguintes provas: contagem de bactérias aeróbicas ou facultativas mesófilas e psicrófilas e de Staphylococcus aureus; determinação do Número Mais Provável (NMP) de coliformes totais e fecais e da presença de Salmonella. As técnicas utilizadas foram aquelas convencionalmente usadas para tais determinações. Não foi encontrada Salmonella em nenhuma das amostras e de cerca de 16,6% delas isolou-se Staphylococcus aureus. em proporções variáveis verificou-se a presença de microrgarnismos deteriorantes e daqueles indicadores de poluição de origem fecal.

Mutagenicity induced by the hydroalcoholic extract of the medicinal plant Plathymenia reticulata Benth

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Atividades preventivas realizadas pelos cirurgiões-dentistas do PSF de Natal-RN

Family Health Program (FHP) presents itself as a restructured model on basic cares besides having prevention practices and promotion in health as essential parts. According to that, the purpose of this study is to perceive which prevention practices in oral health are accomplished by the dentists from the FHP of Natal-RN as well as the way they have been developed, the knowledge basis to execute the procedure and the use of evaluation instruments by the dentists and by the Oral Health Co-Ordinator. A list of dentists participating on the FHP of Natal in March, 2006 (n= 91) was obtained so it was possible to formulate a structured interview. After excluding those with less than six months attending to the program, and considering the loss, eighty dentists got to be interviewed. It had questions about individual and group preventive procedures, sources of basement to develop the activities and to verify the impact and evaluation instruments. Besides that, an interview was made with the Oral Health Co-Ordinator about the evaluating process and the existence of a protocol as well as about document analysis in the Ambulatory Informations System Unique Health System (AIS-UHS), Information of Basic Care System and Pact of Recorder. The main individual activities consist on Oral Hygiene Orientation (87,5%) and Fluoridization (95%). Group activities remain at scholar groups acts(91,25%) being fluoridization done by 91,25% and educative activities by 86,25% mainly through speeches (61,25%).Orientations about oral cancer were detached on the aged group (39,96%)and hypertensive and diabetic group (19,51%), as well as integration with the health team was respectively 21,93% and 39,02%. Speeches and talk rounds are the main activities for aged, hypertensive and diabetics, and are also expressive to pregnant women. For pregnant women and babies group predominate hygiene and diet orientation. About the evaluation instruments 73,75% of the dentists do not consider their existence, despite 73,75% consider that actions have impact specially due to a increase of hygiene and decrease of caries index on the children. The main sources of basement are clinical experience (42,5%) and preparative courses (33,75%), only 7,5% mentioned population need and local reality. The Oral Health Co-Ordinator related the Attention Pact Recorder and records from the AIS - UHS as evaluation source but also detached the lack of epidemiologic surveying. She mentioned the increase of supervised brushing as a positive result and detached the hardness of the professional to act inside the family and as a team. The AIS-UHS records showed that fluoridization is more used individually and the supervised brushing is predominant as a group action, besides that educative activities at the Health Establishment predominate due to actions at the community. Facing the results, it was verified the act in different groups, special attention given to scholars, as well as focus the activities on caries giving less emphasis to other oral problems. Despite that, there was no epidemiologic instruments or data of the local reality to guide the actions and to be part of the planning and evaluation process

Nervos: rede de discursos e práticas de cuidado na atenção básica no município de Natal/RN

The Primary Health Care and one of its main strategies, the Family Health Strategy (ESF), are framed as the gateway to the Public Health System (SUS). Thus, most of the incident and prevalent health problems in the population attended should be solved at this level of care, including psychological suffering, and the so-called complaint of nerves. Nerves and nervous denote a complexity that is not always well comprehended by health workers, in such a way that the care to this kind of problem is usually inadequate. In this line of thought, the general objective of this study is to analyze the network of discourses and the care to the psychological suffering, expressed as nerves, in SUS daily Primary Health Care. Besides and more specifically, it aims at identifying the principles and guidelines of the Primary Health Care in mental health; to investigate health workers positioning before psychological suffering and complaints of nerves, and also analyze different actions and practices of care carried out in different Health Units towards complaints like nerves. Institutional Ethnography was the theoreticalmethodological perspective adopted for the work. This approach seeks to understand and analyze the institutional relationships in a particular context considering sociostructural influences and power relations, as well as daily discourses and practices. Based on interviews with health professionals, informal conversations and observations in six Health Units with ESF teams from different sanitary districts in Natal/RN, it was possible to check that the index of complaint of nerves is high. The referral to psychologists and psychiatrists, as well as the prescription of psychotropic drugs appear as the most common intervention at this level of care. In general, the participants complain that they have poor specialized knowledge about the theme of mental health. They face the problem of bad work conditions and the lack of institutional support, which make actions of illnesses prevention and health promotion even more difficult. Besides, there are different ongoing practices such as meetings for hypertensive and aged people, walk, visit, round-table discussions and community therapy. However, not all of these actions are aimed at the care of psychological suffering. It is observed that the Matrix Support, which is a methodological strategy of supervision and follow up forcases of mental health, hasn t been totally implemented in the municipal system, although it is a tool that has been used by psychologists in some Health Units in the city. It was also verified that the health care practices to the problem of nerves strongly depend on the professional s commitment with the PSF guidelines and on mental health policies, in addition to continued support, when available, from other professional who works as matrix supporter

Participação e ação política dos psicólogos frente à política de saúde mental no Piauí

It is intended to problematize forms of participation and political action of psychologists toward mental health policy in Piauí. The study was motivated through challenges faced by the local Psychiatric Reform movement, and the one underway in the country, which needs support technical-assistence and sociopolitical to guarantee accomplishments and to move on with the complete reversion of the asylum to psychosocial model. The method was based on institutional analysis and counted with three insertion moments for the field research: a) to identify historical and political events that configure the local Psychiatric Reform (documental research/oral memory) and to identify psychologists that act in Mental Health; b) to realize participant observation and semi-structured interview with 33 psychologists which act in Mental Health in Teresina; c) to follow the sociopolitical contexts/events of the local Psychiatric Reform (participant observation and conversation circles). The data were analyzed considering four discussion axes, achieved through categorization of the collected material: 1) ways of professional insertion of psychologists in mental health; 2) knowledge and practices used to act in this work context of the profession; 3) political professional movements of workers of the reformist local process; 4) political action of psychologists toward the course of Piauí mental health policy. We concluded identifying that the participation of psychologists in Piauí mental health finds strength by the conduction of its macro and micropolitical professional action. The first one follows oriented by the lemma of social commitment, despite this movement doesn t have equivalence in the transformation of practices and political-professional postures of psychologists in the daily of services. The second is constituted in the every day of work, standing to the political action of the profession implicated with the preservation of the classic modus operandi of being psychologist. Therefore, it is about the actions that give little sustainability technicalassistance to the Psychiatric Reform underway in the State, and why not say in the country

Ajuda mútua nos CAPS: o papel dos serviços no empoderamento dos usuários

The research objective is explore practices to mutual help between CAPS users from the east and west regions of the city of Natal, RN, in Brazil. In the mental health field, we observe the care from substitutive services is based on technical knowledge where the person of the mental health professional is predominant. The Brazilian psychiatry reform invests in equipments and mental health care protocols, but it is necessary to invest more vigorously in new strategies and actors capable of obtaining resources to achieve this goal, such as the users. If one cornerstone of the psychiatric reform consists of changing the type of relationship established with the person with mental disorders, why this relationship, nowadays, is still dominated by technique and unevenness, where on one side we have a person who knows something and who needs take care of someone, and on other side we have another who knows nothing and thus needs to be cared for? Starting from this problematization of the traditional methods of health/mental health care, an attempt was made to investigate in what ways the mutual help practices between people with mental disorders can realize potential avenues not yet explored within the scope of psychiatric reform. The objective of this research was to map possible mutual help practices among the users, and the technical understanding of such practices. For that, we took part in the daily activities of the CAPS, mapping the experiences of mutual help among users. In addition, we accompanied the users in external activities (such as return home, trips, etc), and we had roundtables with the professionals. The research was guided by theoretical methodological references of the institutional analysis. The results pointed to a lack of behaviors of mutual help or support among users, something that can probably be explained by the service work dynamics, as well as the relationship between technicians and users, which has a tendency to create hurdles for meetings among users, as well as being non-conducive to theirempowerment

Gestão pública em saúde mental: um estudo em CAPS com gerência pública e privada do Rio Grande Do Norte

Currently, several models of management services from the public administration are in operation in Brazil following a global trend. Besides the traditional public management operated in SUS, there are ongoing experiments of privately management in the public health services. Accordingly, we have developed an investigation into two Psychosocial Care Centers operating between these two forms of financial resources management: the first is the CAPS II - PAR situated in the municipality of Parnamirim whose form is private and the second is the CAPS II West Christmas is that the municipal government. We seek to know the workings of services, planning forms and criteria for use of financial resources, identify differences between departments on ways to run and see how technicians and users participate in the planning and management of these resources. Documentary Research was conducted by the municipal Christmas and the financial administration of the CAPS service in Parnamirim. Were conducted an interview with manager (mental health coordinator of Natal) and another interview with an employee of planning department in the Health Department of Natal, an interview with the coordinator and financial administrator of CAPS - PAR and two groups of discussion taped conversation with semi structured script interviews with six technicians in CAPS PAR and six professionals crowded in CAPS - West.Differences were observed in the management of resources funded from four blocks of discussion and analysis of results, where the privately-run service for the direct management and bureaucracy without being discussed and planned spending on staff, as well as through meetings with users, the use of the financial resources available in box; already in service with municipal public administration there is a hierarchy, this answering the coordination of mental health and the local health department that centralizes resources and defines their spending. There are meetings with patients and families, but the demands are limited as to what can be sued because of the manager s authorization. Such differentiation would be related to differences in the articulation of public management with the different types of possible management in public services, where from the implementation of new public administration in the Brazilian s State Management Reform initiated in the second half of the 1990s, benefit management services with private regime, with autonomy and direct transfer of resources