31 resultados para Mergulhadores autônomos
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
The development and refinement of techniques that make simultaneous localization and mapping (SLAM) for an autonomous mobile robot and the building of local 3-D maps from a sequence of images, is widely studied in scientific circles. This work presents a monocular visual SLAM technique based on extended Kalman filter, which uses features found in a sequence of images using the SURF descriptor (Speeded Up Robust Features) and determines which features can be used as marks by a technique based on delayed initialization from 3-D straight lines. For this, only the coordinates of the features found in the image and the intrinsic and extrinsic camera parameters are avaliable. Its possible to determine the position of the marks only on the availability of information of depth. Tests have shown that during the route, the mobile robot detects the presence of characteristics in the images and through a proposed technique for delayed initialization of marks, adds new marks to the state vector of the extended Kalman filter (EKF), after estimating the depth of features. With the estimated position of the marks, it was possible to estimate the updated position of the robot at each step, obtaining good results that demonstrate the effectiveness of monocular visual SLAM system proposed in this paper
Resumo:
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
Resumo:
Auciomar C. T. Cerqueira;Filipe C. A. Lins ; Adelardo A. D. Medeiros ; Pablo J. Alsina1. A versao 2006 da Equipe POTI de futebol de robos. In: CONGRESSO BRASILEIRO DE AUTOMÁTICA,2. Campo Grande, RS, 2006. Anais... Campo Grande: JRI, 2006.
Resumo:
The mollusks present a great taxon variety and life habits in coral reefs being good environmental indicators. It is important to know the distribution pattern of the mollusks and the processes that influence it, so that disturbances in sea ecosystems could be monitored. The present study aims to accomplish the inventory and distribution of epibenthic mollusks in the Parracho of Maracajaú. 23 sites in different habitats of the Parracho were settled: 11 in the reef habitat, 3 in the sandy bottom and 9 in the seagrass bed. Qualitative and quantitative samplings have been done through snorkeling and scuba diving. Three band transects (10m²) were sampled in each site and the data were obtained to each m² of the transect, where the species were counted and the environmental variables (rugosity and recovery of the substratum) were valued. The data were submitted to multivariate analyses in order to find possible distribution patterns that could be associated to the substratum variables. The diversity indexes were calculated for each reef sites and compared with each other. A number of 46 species were registered. The reef habit at should to be the richnest area while the sandy bottom was poorest one. In the reef habitat, the mollusks were associated to rugosity and recovering of frondose algae and zoanthids, while for the seagrass bed, the animals exhibited a richness variation associated to the muddy and sandy sediment. There were found 3 species economically explored, what requires an appropriate management for the maintenance and conservation of the area resources in a sustainable way
Resumo:
The species Dasyatis marianae inhabits coastal areas associated with coral reefs, considered endemic to the northeast of Brazil, occurring from the State of Maranhão to the south of Bahia. Specimens of this species are commonly sighted by divers and fishermen in the area of Maracajaú reefs, a complex reef that is part of the Environmental Protection Area of Coral Reefs (EPACR), which was developed in this study about the ecology and biology of the D. marianae, in order to characterize aspects of population structure in the area of the reef complex of Parracho de Maracajaú. We analyzed 120 specimens caught by artisanal fishing site of the size, weight, sex, stage of maturity and stomach contents. Most subjects were adult males (1.7:1) and was more abundant for rays with lengths between 25 and 29cm of LD, where females reach larger sizes, a feature common to other rays. The largest specimens were captured in the area of seagrass, which is preferred for the species. The distribution of species in the area showed an ontogenetic and sexual segregation, where the youthful occur near the beach, which is a likely area for nursery and growth of the adult females prevail in the seagrass, which apparently has a high prey availability, and Adult males are more distant, a higher proportion occurring in outlying areas, suggesting a habit more exploratory than the females. The evaluation of the reproductive system indicated 3 reproductive cycles per year, one young per pregnancy, and showed that the mature males were smaller than females. The cubs of D. marianae size at birth 12 to 15cm LD. As for diet, the species was characterized as carnivorous crustacean specialist. The performance of visual censuses in different localities allowed to evaluate the density of D. marianae in different environments of the complex. The species occurs in greater numbers in seagrass, environment very important for the conservation of the species. 100 individuals of D. marianae marked in reef complex area enrolled in a recapture rate of 3%. Some behavioral aspects were evaluated, as diurnal pattern of activity, interaction with cleaning and fish Pomacanthus paru followers as Lutjanus analis and Carangoides bartholomaei. Overall, much of the information obtained should be used for management of the species
Resumo:
The current National Policy for Social Assistance (PNAS) is the instrument that regulates the organization and procedures of social-welfare actions. Developed and approved in 2004 since the Unified Social Assistance System (ITS) was crated in 2003, it reaffirms the democratic principles of the Social Assistance Organic Law (LOAS) focusing on the universalization of social rights and equality of rights when accessing the social-welfare system. In the SUAS point of view, the PNAS highlights the information, monitoring and evaluation fields for being the best way to assure the regulation, organization and control by the Federal Government paying attention to the principles of decentralization and participation. This political-institutional rearrangement occurs through the pact among all the three federal entities. The pact deals with the implementation of the task. It says that it has to be shared between the federal autonomous entities, established by dividing responsibilities. To the cities, considered as the smallest territorial unit of the federation and closer to the population, was given the primary responsibility, which is to feed and maintain the database of SUAS NETWORK and identify families living in situations of social vulnerability. In addition to these responsibilities, the cities that have full autonomy in the management of their actions, have the responsibility to organize the basic social protection and the special social protection, that using the Center of Social Assistance Reference (CRAS) and the Center of Specialized Social Assistance Reference (CREAS), are responsible for the provision of programs, projects and services that strengthen the family and community; that promote people who are able to enjoy the benefits of the Continuing benefit of Provisions (BPC) and transfer of incomes; that hold the infringed rights on its territory; that maximize the protective role of families and strengthen its users organization. In Mossoró/RN, city classified as autonomous in the social assistance management, has five units of CRAS that, for being public utilities, are considered the main units of basic social protection, since they are responsible for the connection between the other institutions that compose the network of local social protection. Also known as Family House, the CRAS, among other programs and services, offers the Integral Attention to Families Program (PAIF), Juvenile ProJovem Program, socio-educational coexistence services programs, as well as sending people to other public policies and social-welfare services network, provides information, among others. In this large field, social workers are highlighted as keys to implement the policy of social assistance within the city, followed by psychologists and educators. They should be effective public employees, as a solution to ensure that the provision of the services are to be continued, provided to the population living around the units. However, what we can find here is inattention to the standard rules of social assistance, which not only undermines the quality of programs and services, but also the consolidation of policy on welfare as public policy of social rights
Resumo:
This study critically examines the effects of public policies, implemented by Fundação Estadual da Criança e do Adolescente (FUNDAC/RN), along with adolescents of both sexes, perpetrators of illegal acts in compliance by court order, by socio-educative measures , identifying the contradictions that permeate the understanding and treatment of issue. The aim is to investigate the chances that youths have by living in Centro Educacional Pitimbu and Centro Educacional Padre. João Maria (CEDUC), to become subjects in the exercise of their citizenship. The methodology adopted is the verbal history of life (MEIHY, 2005) of youths that had life experiences in these institutions from 2002 to 2005, allowing researchers to access directly to investigated individuals, through the place where they currently reside, and enabling the reconstitution of their life story, from semi-structured interviews. The young people s statements interviewed were grouped and analyzed from the following categories of analysis: the egress and family, the school and egress, the community and egress, the egress and work, the egress and CEDUC, the egress and experience infringement. The results indicate that, despite the advances in Brazilian legislation for the sector, the actions promoted by these institutions generally would have produced innocuous and stigmatized consequences. Moreover, they show in essence that they carry on their inner contradictions which fundamentally correspond to the interests of the dominant system and a society which uses mechanisms of social policy, in addition to favoring the control and repression. And thus, while such actions remain unable to produce important changes in the conditions of existence of young people who meet by social deprivation of liberty, it is possible to say that the chances are minimal so that they become autonomous subjects in a society that, preferring their punishment, denies them, stubbornly, access to their basic rights. In theory, the researcher dialogues with authors as Foucault, Goffman, Bourdieu, Offe, Bauman, Boaventura Santos, Takeuti, Germano, Ariès, Wacquant, among others
Resumo:
The study made in this thesis analyzes the new form of work organization at the urban collective transportation sector, so called Altemative Transportation which is a new form of public transportation that appears in the Brazilian urban context by the mid ninety' s, this work is made by independent or sub-contracted workers, usually organized in cooperatives . It reflects the investigation of new forms of precarious work, unformal which has been expanding in the urban transportation sector. Thus, discusses non regulation of the services sector problem the ways of survival of exc1uded workers from the formal work market mainly afier the capital productive restructure. It has as privileged area of investigation, the sector policy of urban transportation that make field of the main nets of political articulations that define the dynamic of the urban space. It is known that the urban collective transportation allows the access to the production, circulation and general consumption being necessary to the mobility of the resident population, mainly to those with low purchasing capacity. It becomes a field of empirical investigation at the Belem municipal, located at the Amazonic region - north Brazil. The main points dealed on this research start from concrete relations from the daily life of workers that deve1op their activity on the altemative transport mediated with theoretical references needed for understanding and interpretation of the studied reality. The investigation strategies were built from the abstract (theorical knowledge produced for the reality analyze) in concrete by the investigation quantitative-qualitative from this area of urban policy, making up possible the formation of a references chart to the analyses of the studied subject. Rescue his historicity, from characterization of the urban space of the metropolitan region of Belem passing true the forms of organization and urban services performances while essential production and reproduction element of the social relations. Identifies the main individuals that historically have been participating in the construction of the municipality transport policy and the ways of expression of the local political strength relations. Outstand the State paper on the net of established relations near the local power, as well as outstand the importance of social sciences in the understanding of urban policies in the transportation area, trying to bring input to the academicals -scientific debate .The above e1ected and mentioned points in this study are crucial for a critical reflection of the transportation policies. That relation is not given, but historically built at the power relation chart that makes up this unique area of the urban policies
Resumo:
Broadly anchored on Institutionalist literature this dissertation seeks to answer: Why rural credit granted to farming families in Rio Grande do Norte, Pronaf group B, has shown positive results in some territories while in others the same results are insatisfactory? Considering formal rules are the same, then why such results are so distinguished? This research supports the fact that these results are a direct consequence of the quality of institutions defined as longstanding social rules established and built in social interactions. For institutions one understands; organizational structures, formal and non-formal rules, social trust, thinking behaviors and its evolution as well as routines. Using Pronaf Rural Credit as a background this study measures and compares results obtained in the rural areas of Seridó, Sertão do Apodi, Mato Grande, Assú-Mossoró, Trairi, Potengi and Alto Oeste. The dimensions of measurement considered were: economics, social and guarantee of transparency. The study considers a sample of 402 Group B farming families. It also elaborates a socio-economic profile of these families in the considered areas and underlines the main causes for defaulted loans, difficulties to improve family income and results of access to Pronaf B credit line, as well as it proposes solutions to surpass obstacles to improve the efficiency of this credit line
Resumo:
The studies in the education area have been defending the importance of forming autonomous teachers that they look for to understand the context in that they act, for that movement to make possible educational interventions with better conditions of the students' learning. In the extent of the teachers' formation, it has been discussed the importance of formative actions that they have as focus the analysis of the needs in the educational formation, as alternative to turn such more significant actions. Concerned with those subjects and with the school failure in the Brazilian education, especially in the children's of the public school literacy, we accomplished this work that aims at to investigate the needs of teachers' of the Fundamental Teaching of the public school formation, in the extent of their students' orthographic difficulties, building with those teachers knowledge on the process of teaching/learning spelling. The study was accomplished at a municipal school of the city of Parnamirim-RN, that offers the Fundamental Teaching I. the approach investigativa is of qualitative nature, where the case study and the research-action were used as methodologies. They participated in the research 7 teachers and 1 coordinator of the institution. For the construction of the data the following instruments were used: glimpsed semi-directing collective and individual, documental analysis, questionnaire and observation, that made possible the triangulation of the data for the content analysis. The main results pointed that the teachers' of that school initial needs were addressed not only to the teaching of the spelling, but also to the formation type that they would receive. We verified although the formative process was favorecedor of sockets of the teachers' conscience: related to the orthographic mistakes, to the strategies used at classroom and to the planning addressed to the teaching of the spelling. Finally, we concluded that the teachers' reflection researched about their own formation needs contributed for (trans)formations of their conceptions and practices related to the teaching of the spelling, even before some found difficulties, so much in the formation as in practice pedagogic developed by the participants
Resumo:
This thesis aims to enable a wider comprehension on thought operation as well as suggest alternatives for the formation of reflexive, critical, autonomous and creative individuals. The research defends the idea that it is possible for an individual to develop vigilant attention that makes thought flexibilization and change in the course of action, possible. This operation is called Internal Dialogue and is essentially characterized by a continuous openness towards novelty and learning. This makes it possible to minimize the usual way thought operates, in a automatic fashion (automatism). The research was based on theoretical references and ideas of David Bohm (1989;1994;2005) and Michael Polanyi (1983). The main emphasis was the understanding that a crisis situation enables awareness and state of alert that favors a more flexible thought pattern (Aragão Gomes, 1994, 1997). The methodology used was presentation and analysis of these moments through autobibliographical records with indication of crisis on behalf of the subjects. Other criteria were also used that enabled the composition of the analyzed material such as the fact that: the subjects were public and real, the data was available through accessible material; the subjects identified themselves as in crisis; these crisis were of varied kinds; they had different social, cultural and professional profiles. Thus, three auto-bibliographical elements were selected: the Infidel: the story of a woman that challenged Islam (2007), written by the political Muslim author Ayaan Hirsi; Still me: memories (2001), of the actor Christopher Reeve as well as Confessions of a Philosopher (2001), by the philosopher Bryan Magee. In these books an analysis was made related to parts that stated action an though operation that express internal dialogue. These were organized into categories that were pointed out as relevant for the identification of internal dialogue such as: Perceptions of physical reaction; emotions, beliefs and issues, individual actions, self judgment and thought, self questioning, comprehension, observation and empirical investigation, perception of the changes they performed in the world, escape of conditioning as well as action that resulted in new meaning. The analysis performed reinforces our goal once it sated that internal dialogue is an important tool that allows thought awareness, minimizing common automatism and making consciousness possible as well as favoring the occurrence of critical and reflexive thought. Thus, final considerations deal with the need for the development of teaching methodologies that address internal dialogue as a counterpoint to the many daily action that reinforce the automatism of thought
Resumo:
This thesis aims to enable a wider comprehension on thought operation as well as suggest alternatives for the formation of reflexive, critical, autonomous and creative individuals. The research defends the idea that it is possible for an individual to develop vigilant attention that makes thought flexibilization and change in the course of action, possible. This operation is called Internal Dialogue and is essentially characterized by a continuous openness towards novelty and learning. This makes it possible to minimize the usual way thought operates, in a automatic fashion (automatism). The research was based on theoretical references and ideas of David Bohm (1989;1994;2005) and Michael Polanyi (1983). The main emphasis was the understanding that a crisis situation enables awareness and state of alert that favors a more flexible thought pattern (Aragão Gomes, 1994, 1997). The methodology used was presentation and analysis of these moments through autobibliographical records with indication of crisis on behalf of the subjects. Other criteria were also used that enabled the composition of the analyzed material such as the fact that: the subjects were public and real, the data was available through accessible material; the subjects identified themselves as in crisis; these crisis were of varied kinds; they had different social, cultural and professional profiles. Thus, three auto-bibliographical elements were selected: the Infidel: the story of a woman that challenged Islam (2007), written by the political Muslim author Ayaan Hirsi; Still me: memories (2001), of the actor Christopher Reeve as well as Confessions of a Philosopher (2001), by the philosopher Bryan Magee. In these books an analysis was made related to parts that stated action an though operation that express internal dialogue. These were organized into categories that were pointed out as relevant for the identification of internal dialogue such as: Perceptions of physical reaction; emotions, beliefs and issues, individual actions, self judgment and thought, self questioning, comprehension, observation and empirical investigation, perception of the changes they performed in the world, escape of conditioning as well as action that resulted in new meaning. The analysis performed reinforces our goal once it sated that internal dialogue is an important tool that allows thought awareness, minimizing common automatism and making consciousness possible as well as favoring the occurrence of critical and reflexive thought. Thus, final considerations deal with the need for the development of teaching methodologies that address internal dialogue as a counterpoint to the many daily action that reinforce the automatism of thought
Resumo:
This work introduces a new method for environment mapping with three-dimensional information from visual information for robotic accurate navigation. Many approaches of 3D mapping using occupancy grid typically requires high computacional effort to both build and store the map. We introduce an 2.5-D occupancy-elevation grid mapping, which is a discrete mapping approach, where each cell stores the occupancy probability, the height of the terrain at current place in the environment and the variance of this height. This 2.5-dimensional representation allows that a mobile robot to know whether a place in the environment is occupied by an obstacle and the height of this obstacle, thus, it can decide if is possible to traverse the obstacle. Sensorial informations necessary to construct the map is provided by a stereo vision system, which has been modeled with a robust probabilistic approach, considering the noise present in the stereo processing. The resulting maps favors the execution of tasks like decision making in the autonomous navigation, exploration, localization and path planning. Experiments carried out with a real mobile robots demonstrates that this proposed approach yields useful maps for robot autonomous navigation
Resumo:
Simulations based on cognitively rich agents can become a very intensive computing task, especially when the simulated environment represents a complex system. This situation becomes worse when time constraints are present. This kind of simulations would benefit from a mechanism that improves the way agents perceive and react to changes in these types of environments. In other worlds, an approach to improve the efficiency (performance and accuracy) in the decision process of autonomous agents in a simulation would be useful. In complex environments, and full of variables, it is possible that not every information available to the agent is necessary for its decision-making process, depending indeed, on the task being performed. Then, the agent would need to filter the coming perceptions in the same as we do with our attentions focus. By using a focus of attention, only the information that really matters to the agent running context are perceived (cognitively processed), which can improve the decision making process. The architecture proposed herein presents a structure for cognitive agents divided into two parts: 1) the main part contains the reasoning / planning process, knowledge and affective state of the agent, and 2) a set of behaviors that are triggered by planning in order to achieve the agent s goals. Each of these behaviors has a runtime dynamically adjustable focus of attention, adjusted according to the variation of the agent s affective state. The focus of each behavior is divided into a qualitative focus, which is responsible for the quality of the perceived data, and a quantitative focus, which is responsible for the quantity of the perceived data. Thus, the behavior will be able to filter the information sent by the agent sensors, and build a list of perceived elements containing only the information necessary to the agent, according to the context of the behavior that is currently running. Based on the human attention focus, the agent is also dotted of a affective state. The agent s affective state is based on theories of human emotion, mood and personality. This model serves as a basis for the mechanism of continuous adjustment of the agent s attention focus, both the qualitative and the quantative focus. With this mechanism, the agent can adjust its focus of attention during the execution of the behavior, in order to become more efficient in the face of environmental changes. The proposed architecture can be used in a very flexibly way. The focus of attention can work in a fixed way (neither the qualitative focus nor the quantitaive focus one changes), as well as using different combinations for the qualitative and quantitative foci variation. The architecture was built on a platform for BDI agents, but its design allows it to be used in any other type of agents, since the implementation is made only in the perception level layer of the agent. In order to evaluate the contribution proposed in this work, an extensive series of experiments were conducted on an agent-based simulation over a fire-growing scenario. In the simulations, the agents using the architecture proposed in this work are compared with similar agents (with the same reasoning model), but able to process all the information sent by the environment. Intuitively, it is expected that the omniscient agent would be more efficient, since they can handle all the possible option before taking a decision. However, the experiments showed that attention-focus based agents can be as efficient as the omniscient ones, with the advantage of being able to solve the same problems in a significantly reduced time. Thus, the experiments indicate the efficiency of the proposed architecture
Resumo:
In multi-robot systems, both control architecture and work strategy represent a challenge for researchers. It is important to have a robust architecture that can be easily adapted to requirement changes. It is also important that work strategy allows robots to complete tasks efficiently, considering that robots interact directly in environments with humans. In this context, this work explores two approaches for robot soccer team coordination for cooperative tasks development. Both approaches are based on a combination of imitation learning and reinforcement learning. Thus, in the first approach was developed a control architecture, a fuzzy inference engine for recognizing situations in robot soccer games, a software for narration of robot soccer games based on the inference engine and the implementation of learning by imitation from observation and analysis of others robotic teams. Moreover, state abstraction was efficiently implemented in reinforcement learning applied to the robot soccer standard problem. Finally, reinforcement learning was implemented in a form where actions are explored only in some states (for example, states where an specialist robot system used them) differently to the traditional form, where actions have to be tested in all states. In the second approach reinforcement learning was implemented with function approximation, for which an algorithm called RBF-Sarsa($lambda$) was created. In both approaches batch reinforcement learning algorithms were implemented and imitation learning was used as a seed for reinforcement learning. Moreover, learning from robotic teams controlled by humans was explored. The proposal in this work had revealed efficient in the robot soccer standard problem and, when implemented in other robotics systems, they will allow that these robotics systems can efficiently and effectively develop assigned tasks. These approaches will give high adaptation capabilities to requirements and environment changes.