ISEP - LSA - Laboratório de Sistemas Autónomos
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LSA is a R&D unit from ISEP the Engineering School of Porto Polytechnic. It conducts research in autonomous systems and related areas such as navigation, control and coordination of multiple robots.The laboratory activity is developed in four lines of work:
R&D programs;
Educational project;
Dissemination projects;
Strategic positioning projects for the school ISEP/IPP.
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- An automated maneuver control framework for a remotely operated vehiclePublication . Fraga, S. L.; Sousa, J. Borges de; Girard, Anouck; Martins, AlfredoAn automated maneuver control framework for a remotely operate vehicle (ROV) is presented. This framework entails a three-layered control architecture, a principled approach to design and implementation within the architecture, and hybrid systems design techniques. The control architecture is structured according to the principle of composition of vehicle motions from a minimal set of elemental maneuvers that are designed and verified independently. The principled approach is based on distributed hybrid systems techniques, and spans integrated design, simulation and implementation as the same model is used throughout. Hybrid systems control techniques are used to synthesize the elemental maneuvers and to design protocols, which coordinate the execution of elemental maneuvers within a complex maneuver. The architecture is fault-tolerant by design since it uses verified maneuvers. This work is part of the Inspection of Underwater Structures (IES) project whose main objective is the implementation of a ROV-based system for the inspection of underwater structures
- A control framework for a remotely operated vehiclePublication . Sousa, J. Borges de; Fraga, Sérgio; Martins, Alfredo; Pereira, F. L.A control framework enabling the automated maneuvering of a Remotely Operate Vehicle (ROV) is presented. The control architecture is structured according to the principle of composition of vehicle motions from a minimal set of elemental maneuvers that are designed and verified independently. The principled approach is based on distributed hybrid systems techniques, and spans integrated design, simulation and implementation as the same model is used throughout. Hybrid systems control techniques are used to synthesize the elemental maneuvers and to design protocols, which coordinate the execution of elemental maneuvers within a complex maneuver. This work is part of the Inspection of Underwater Structures (IES) project whose main objective is the implementation of a ROV-based system for the inspection of underwater structures.
- Design of the ISePorto robocup Middle-Size League Robotic Soccer Team: Control, Localisation and CoordinationPublication . Martins, Alfredo; Almeida, José; Silva, Eduardo; Baptista, João PauloThis paper describes the design and implementation status of the ISePorto robotic football team for participation in Robocup Middle Size League (F2000). The objectives guiding the project were the applications and research in hybrid control and coordination systems. The system has also an educational support role. A special attention is made to the custom design to allow the execution of complex manoeuvres and team coordinated behaviours. The robot has different pass, shot, and manoeuvre capabilities providing high level tactical and strategic planing and coordination. The current team status is also covered.
- Coordinated Maneuver for Gradient Search Using Multiple AUV'sPublication . Martins, Alfredo; Almeida, José; Silva, EduardoThe coordinated use of multiple Autonomous Underwater Vehicles can provide important advantages for oceanographic missions. One important mission application scenario can be the search of underwater plumes such as sources of freshwater of hydrothermal vents. These plumes characterize the environment by creating a gradient field of some measurable physical quantity. An innovative integrated acoustic navigation system and coordination control maneuver for a formation of 3 AUVs and 1 surface craft to gradient search and following missions is proposed. The specific formation geometry and topology takes in account the navigation and coordination requirements. It was designed to achieve an efficient, low cost and technically feasible solution. The system can operate in 3 modes depending on formation distances. Varying pinging rates and offsets are used to communicate parameters and mode changing. No additional underwater communication systems neither acoustic transponder deployment are needed for the vehicle coordination. This way a high degree of energy efficiency and overall mission low cost and simpler logistics is achieved. The hybrid nature of the coordinating maneuver allows the formation gradient survey and following with the efficient exploitation of the environment structuring by the phenomena to be studied. The individual control laws were designed in order to minimize the inter-vehicle communication. The coordination factors are the knowledge by the vehicles of each other behavior (since all vehicles execute the same control laws) and the detection of formation distortions. These distortions are detected by the relative navigation system. The proposed approach allows the low cost implementation of a multiple AUV coordinating control for a large range of oceanographic missions.
- Control and Localisation for the ISePorto Robotic Soccer TeamPublication . Almeida, José; Martins, Alfredo; Silva, EduardoThis paper describes the control and localisation design and implementation status of the ISePorto robotic football team for participation in Robocup Middle Size League (F2000). The objectives guiding the project were the applications and research in hybrid control and coordination systems. The system has also an educational support role. A special attention is made to the custom design to allow the execution of complex manoeuvres and team coordinated behaviours. The robot has different pass, shot, and manoeuvre capabilities providing high level tactical and strategic planing and coordination.
- Hybrid Maneuver for Gradient Search with Multiple Coordinated AUVsPublication . Martins, Alfredo; Silva, Eduardo; Pereira, Fernando L.; Almeida, JoséThis work presents a hybrid maneuver for gradient search with multiple AUV's. The mission consists in following a gradient field in order to locate the source of a hydrothermal vent or underwater freshwater source. The formation gradient search exploits the environment structuring by the phenomena to be studied. The ingredients for coordination are the payload data collected by each vehicle and their knowledge of the behaviour of other vehicles and detected formation distortions.
- ISePorto Robotic Soccer Team: A New Player GenerationPublication . Cerqueira, V.; Dias, André; Matos, Nuno; Almeida, J. M.; Martins, A.; Silva, E. P.This paper describes the recent modifications in ISePorto MSL robotic football team and future improvements concerning the development and evolution of the team. The robot was substantially redesigned in order to achieve high reliability, allow better control and coordination capabilities and substantial increase in perception. New mechanical and hardware redesign is presented. Motion control subsystems, new vision hardware sensor and overall architecture are described. The team redesign is done for preparation for participating in the Robocup 2004. The main goal is to achieve not only an important evolution in the team control and coordination but also increased overall reliability.
- BoaVista – Sensor Dedicado de Visão Artificial Baseado em Hardware (Re)configurávelPublication . Lima, Luís; Almeida, José; Martins, Alfredo; Silva, EduardoEste artigo aborda o projecto de um sistema de visão dedicado para robótica móvel autónoma, que beneficia das capacidades de execução paralela do hardware reconfigurável, processando em “pipeline” as imagens provenientes de um sensor de imagem CMOS de alto desempenho em simultâneo com a aquisição das mesmas. Apresentamos um sistema com a capacidade de adquirir e processar imagens com resoluções de 640x480 a uma taxa de 60 fps, baixo custo e capaz de disponibilizar para o sistema central apenas a informação pretendida extraída da imagem. Este ponto, permite libertar os recursos computacionais do robot traduzindo-se em reduções de consumo significativas e consequente aumento da autonomia energética do mesmo.
- A New ROV Design: Issues on Low Drag and Mechanical SymmetryPublication . Gomes, Rui; Fraga, Sérgio; Sousa, Alexandre; Fraga, Sérgio Loureiro; Martins, Alfredo; Sousa, J. Borges de; Pereira, Fernando LoboThis paper reports the design of a new remotely operated underwater vehicle (ROV), which has been developed at the Underwater Systems and Technology Laboratory (USTL) - University of Porto. This design is contextualized on the KOS project (Kits for underwater operations). The main issues addressed here concern directional drag minimization, symmetry, optimized thruster positioning, stability and layout of ROV components. This design is aimed at optimizing ROV performance for a set of different operational scenarios. This is achieved through modular configurations which are optimized for each different scenario.
- Modelação de um Mercado da Pequena Geração Dispersa através de Agentes e Serviços WebPublication . Correia, Nuno Alexandre Sarmento; Malucelli, Andreia; Fidalgo, José Nuno; Custódio, Luís Manuel Marques; Malheiro, BeneditaO objectivo deste trabalho é a criação de um modelo do mercado energético da pequena geração dispersa através de serviços Web, agentes m´oveis e leilões. Neste cenário, o mercado, supervisionado pelo leiloeiro, ´e constituído basicamente por dois tipos de actores: os vendedores – com uma determinada carteira de pequenos produtores de energia, equipados com diversos tipos de geradores, e os compradores – entidades que distribuem e comercializam energia, bem como grandes consumidores. Apresenta-se a arquitectura adoptada, composta por agentes estáticos e agentes m´oveis, assim como a metodologia de desenvolvimento integrado elegida. Esta metodologia especifica uma abordagem, suportada pela tecnologia XML, que permite, a partir da informação relativa aos intervenientes, criar uma ontologia comum de representação do conhecimento do domínio, gerar automaticamente os agentes que modelam os intervenientes e, por ultimo, ´ transformá-los em serviços Web. Os agentes compradores e vendedores participam no mercado através de agentes m´oveis, a quem delegam a sua representação durante o leilão. O trabalho, que está em curso, encontra-se na fase do desenvolvimento dos agentes/serviços Web.