Análise cinemática via quatérnios duais aplicada a um sistema veículo-manipulador subaquático

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Automação e Sistemas, Florianópolis, 2011Este trabalho propõe metodologias para a análise cinemática de sistemas veículo-manipulador subaquáticos (UVMS) através de quatérnios duais com o intuito de impor menor variação de torque nas juntas durante o seguimento de trajetória. Em adição a isso, evita-se a ocorrência de singularidades cinemáticas e obtém-se menor custo computacional. A abordagem é apresentada inicialmente como uma alternativa à representação tradicional dos movimentos aplicada na cinemática direta de mecanismos através da convenção de Denavit-Hartenberg e do método dos helicoides sucessivos. O benefício dessa representação está no menor custo computacional, mas principalmente, no desacoplamento dos ângulos de orientação de forma a evitar as singularidades cinemáticas. Os quatérnios duais também são aplicados na cinemática inversa em uma metodologia interativa através do método de Davies como uma modalidade de realimentação livre de singularidades. Por fim, a principal contribuição deste trabalho está na proposta da aplicação dos quatérnios duais na cinemática inversa diferencial em por uma metodologia analítica, através da apresentação do Jacobiano dual-quaterniônico. Essas abordagens são aplicadas a um sistema subaquático, onde o amortecimento imposto pela imersão no fluido dissipa grandes variações de torque e agrega erros no seguimento da trajetória.This work proposes a methodology for kinematic analysis of underwater vehicle-manipulator systems (UVMS) using dual-quaternions. The objective is to provide a less joint torque variation to trajectory tracking, avoidance of kinematic singularities occurrence and a lower computational cost. The approach is initially presented as an alternative representation of movements applied to direct kinematics through the Denavit- Hartenberg convention and the successive screws method. The benefit of this representation is a lower computational cost, but mainly, the decoupling of orientation angles in order to avoid kinematic singularities. The dual quaternions also are applied in the inverse kinematics in an interactive approach through Davies method as a feedback without singularities. Finally, the main contribution of this work is the proposal of dual quaternions application in an analytical approach of differential inverse kinematics through of the dual-quaternionic Jacobian. These approaches are applied to an underwater system, where the damping imposed by fluid immersion dissipates large torque variations adding errors in trajectory tracking

Retrofitting de robôs manipuladores com incorporação de controle de posição e força: aplicação em um robô industrial

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Mecânica.O presente trabalho aborda o retrofitting de manipuladores, através de uma proposta de modelo de referência para o desenvolvimento de controladores de robôs com arquitetura totalmente aberta. O enfoque principal é o desenvolvimento de um padrão de arquitetura funcional organizada em uma estrutura hierárquica, levando em consideração os requisitos e as tendências atuais para o desenvolvimento dessa modalidade de sistema. Esta dissertação pode ser dividida em três grandes etapas. A primeira, denominada de planejamento, estuda os requisitos, as definições e as categorias de controladores de arquitetura aberta e apresenta uma proposta de modelo de referência para o desenvolvimento de controladores de robôs. Na segunda etapa, nomeada de desenvolvimento, ocorre a criação integral de um controlador de robôs (i.e., do software, middleware, hardware e firmware) com arquitetura totalmente aberta. Baseando-se no modelo de referência proposto, enfatizando as tarefas de controle de posição e força. Por fim, apresenta-se a etapa de validação e experimentação, com a aplicação do controlador de robôs desenvolvido no manipulador industrial REIS Rv15 e a incorporação de um transdutor de força ao sistema. Assim, validando o retrofitting do manipulador com a implantação de uma estrutura de controle indireto de força. A concepção de controlador desenvolvida cumpriu os seguintes requisitos: alta capacidade de processamento, baixo custo, conectividade com outros sistemas, disponibilidade de acesso remoto, facilidade de manutenção, flexibilidade no desenvolvimento de algoritmos, integração com um computador pessoal e programação em alto nível. O estudo realizado neste trabalho agrega ao Laboratório de Robótica (LAR) o conhecimento integral da estrutura interna de um controlador de robôs com arquitetura aberta. Dessa forma, aumentando potencialmente as possibilidades de estudos na área da robótica, com um custo significativamente inferior as soluções disponíveis no mercado

ARENA—augmented reality to enhanced experimentation in smart warehouses

The current industrial scenario demands advances that depend on expensive and sophisticated solutions. Augmented Reality (AR) can complement, with virtual elements, the real world. Faced with this features, an AR experience can meet the demand for prototype testing and new solutions, predicting problems and failures that may only exist in real situations. This work presents an environment for experimentation of advanced behaviors in smart factories, allowing experimentation with multi-robot systems (MRS), interconnected, cooperative, and interacting with virtual elements. The concept of ARENA introduces a novel approach to realistic and immersive experimentation in industrial environments, aiming to evaluate new technologies aligned with the Industry 4.0. The proposed method consists of a small-scale warehouse, inspired in a real scenario characterized in this paper, managing by a group of autonomous forklifts, fully interconnected, which are embodied by a swarm of tiny robots developed and prepared to operate in the small scale scenario. The AR is employed to enhance the capabilities of swarm robots, allowing box handling and virtual forklifts. Virtual laser range finders (LRF) are specially designed as segmentation of a global RGB-D camera, to improve robot perception, allowing obstacle avoidance and environment mapping. This infrastructure enables the evaluation of new strategies to improve manufacturing productivity, without compromising the production by automation faults.info:eu-repo/semantics/publishedVersio

DeepSpatial: Intelligent Spatial Sensor to Perception of Things

This paper discusses a spatial sensor to identify and track objects in the environment. The sensor is composed of an RGB-D camera that provides point cloud and RGB images and an egomotion sensor able to identify its displacement in the environment. The proposed sensor also incorporates a data processing strategy developed by the authors to conferring to the sensor different skills. The adopted approach is based on four analysis steps: egomotive, lexical, syntax, and prediction analysis. As a result, the proposed sensor can identify objects in the environment, track these objects, calculate their direction, speed, and acceleration, and also predict their future positions. The on-line detector YOLO is used as a tool to identify objects, and its output is combined with the point cloud information to obtain the spatial location of each identified object. The sensor can operate with higher precision and a lower update rate, using YOLOv2, or with a higher update rate, and a smaller accuracy using YOLOv3-tiny. The object tracking, egomotion, and collision prediction skills are tested and validated using a mobile robot having a precise speed control. The presented results show that the proposed sensor (hardware + software) achieves a satisfactory accuracy and usage rate, powering its use to mobile robotic. This paper's contribution is developing an algorithm for identifying, tracking, and predicting the future position of objects embedded in a compact hardware. Thus, the contribution of this paper is to convert raw data from traditional sensors into useful information.info:eu-repo/semantics/publishedVersio

A quadral-Fuzzy control approach to flight formation by a fleet of unmanned aerial vehicles

This paper addresses the control of a fleet of unmanned aerial systems (UAVs), termed as drones, for flight formation problems. Getting drones to fly in formation is a relevant problem to be solved when cooperative cargo transportation is desired. A general approach for this problem considers the coordination of a fleet of UAVs, by fusing all information coming from several individual sensors posed on each UAVs. However, this approach induces a high cost as every UAV should have its advanced perception system. As an alternative, this paper proposes the use of a single perception system by a fleet composed of several elementary drones (workers) with primitive low-cost sensors and a leader drone carrying a 3D perception source. We propose a Quadral-Fuzzy approach to ensure that all drones fly in formation and will not collide with each other or with environment obstacles. We also develop a new way to compute potential fields based on possibility fuzzy (fuzziness) measure with the focus of avoiding collisions between the drones. The proposed approach encompasses four high-coupled intelligent controllers that respectively control the leader and worker drones' motion and implement obstacle and collision avoidance procedures. Simulation results using a fleet of four aerial drones are presented, showing the potential for solving usual problems to flights in formation, such as dodging obstacles, avoiding collisions between the drones, among others.This work was supported in part by the National Counsel of Technological and Scientific Development of Brazil (CNPq), in part by the Coordination for the Improvement of Higher Level People (CAPES), in part by the Brazilian Ministry of Science, Technology, Innovation and Communication (MCTIC), and in part by the Robotics and Internet-of-Things Lab in Prince Sultan University.info:eu-repo/semantics/publishedVersio

Proposal of an augmented reality tag uav positioning system for power line tower inspection

Autonomous inspection Unmanned Aerial Vehicle systems are an essential research area, including power line distribution inspection. Considerable efforts to solve the demanding presented in the autonomous U AV inspection process are present in technical and scientific research. One of these challenges is the precise positioning and fly control of the U AV around the energy structures, which is vital to assure the security of the operation. The most common techniques to achieve precise positioning in UAV fly are Global Positioning Systems with RealTime Kinematic. This technique demands a proper satellite signal receiving to work appropriately, sometimes hard to achieve. The present work proposes a complementary position data system based on augmented reality tags (AR Tags) to increase the reliability of the UAV fly positioning system. The system application is proposed for energy power tower inspections as an example of use. The adaptation to other inspection tasks is possible whit some small changes. Experimental results have shown that an increase in the position accuracy is accomplished with the use of this schema.info:eu-repo/semantics/publishedVersio

Pistas para escribir un texto

Instruções com dicas para desenvolver um texto. Utilizado na disciplina Língua Espanhola VIII, 2011

Herbicide resistance technologies in soybean cultivars

The objective of this work was to carry out a technical analysis of the biotechnologies that confer resistance to herbicides in soybeans. Two experiments were carried out (I and II) in the agricultural years 2016/17 and 2017/18, using a randomized block design with six  and four  replicates. In experiment I, two forms of management in weed control were evaluated for each technology studied (Roundup Ready® and Liberty Link®) and for conventional soybeans, as well as grain yield. In experiment II, the efficiency of using different herbicides to control voluntary soybeans (with and without technology) was evaluated. The pre-emergent herbicides in both managements proposed for the cultivars controlled the weeds from the emergence of the soybean crop to the application of the post-emergent herbicides in both crops. Likewise, all post-emergent herbicides showed weed control above 90% at 14 and 28 days after application. In the evaluation of the chemical control of Garra IPRO voluntary soybean, the herbicide 2,4-D stood out among the others for being more efficient in both agricultural years (above 90%). The herbicides glyphosate, 2,4-D and metsulfuron-methyl are the most effective in controlling voluntary soybean cultivars BRS 284 and CZ16B39LL

Evaluation of Soil Re-mineralizer from By-Product of Volcanic Rock Mining: Experimental Proof Using Black Oats and Maize Crops

This study was focused on physical, petrographical, mineralogical, and chemical characterization of a volcanic-rock mining by-product (dacite rock), as well as on greenhouse experiment with black oats and maize crops to evaluate the potential use of the by-product as soil re-mineralizer. The by-product sample was obtained from a quarry in the Nova Prata mining district in southern Brazil. The particle size distribution of the by-product and soil was determined by sieving. Dacite rock petrographic description was performed on a polished thin section by optical microscopy. The soil and dacite rock mineralogical phases were identified by X-ray diffraction. The by-product and soil chemical composition was determined by X-ray fluorescence. Inductively coupled plasma mass spectrometry was performed to determine potentially toxic elements, As, Cd, Hg and Pb in by-product. Additional chemical compositions of the by-product and soil were analyzed using a scanning electron microscope equipped with an energy dispersive X-ray detector. Black oats and, sequentially maize, crops were cultivated in a typical Hapludox soil treated with the by-product in a greenhouse. Five by-product doses (0, 906, 1813, 3625, and 7251 kg ha−1) were added into pots containing soil, each with seven replications. Responses to treatments were evaluated from dry matter production, nutritional status of the crops, and in the changes in soil properties after 70 days of each cultivation. The results showed that the by-product is composed of plagioclase, K-feldspar, quartz, clinopyroxene, smectites, and opaque minerals with apatite as accessory mineral. The addition of 3625 and 7251 kg ha−1 doses of the by-product substantially increased the dry matter yield in maize leaves. The Ca uptake by maize leaves cultivated in soil with 7251 kg ha−1 dose of the by-product was significantly higher in soil with other doses, and all by-product doses promoted high concentrations of Mg and Ca. The accumulated amounts of Ca, K, Mg and P indicated that they were enough to supply maize nutritional needs. Improvements in soil properties, such as high levels of Ca, K and P and low levels of exchangeable Al and Al saturation were observed. The results of the study suggest that the by-product can be used as soil re-mineralizer. The dacite rock by-product studied here has potential to be an environmental solution to soil fertilization problem because it does not require chemical processing and can be used as it is mined