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- 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.
- 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.
- 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.
- Radar Based Collision detection developments on USV ROAZ IIPublication . Almeida, Carlos; Franco, Tiago; Ferreira, Hugo; Martins, Alfredo; Santos, Ricardo; Almeida, José Miguel; Carvalho, João; Silva, EduardoThis work presents the integration of obstacle detection and analysis capabilities in a coherent and advanced C&C framework allowing mixed-mode control in unmanned surface systems. The collision avoidance work has been successfully integrated in an operational autonomous surface vehicle and demonstrated in real operational conditions. We present the collision avoidance system, the ROAZ autonomous surface vehicle and the results obtained at sea tests. Limitations of current COTS radar systems are also discussed and further research directions are proposed towards the development and integration of advanced collision avoidance systems taking in account the different requirements in unmanned surface vehicles.
- 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.
- Manoeuvre Based Mission Control System for an Autonomous Surface VehiclePublication . Dias, Nuno; Almeida, Carlos; Ferreira, Hugo; Almeida, José; Martins, Alfredo; Dias, André; Silva, EduardoIn this work the mission control and supervision system developed for the ROAZ Autonomous Surface Vehicle is presented. Complexity in mission requirements coupled with flexibility lead to the design of a modular hierarchical mission control system based on hybrid systems control. Monitoring and supervision control for a vehicle such as ROAZ mission is not an easy task using tools with low complexity and yet powerful enough. A set of tools were developed to perform both on board mission control and remote planning and supervision. “ROAZ- Mission Control” was developed to be used in support to bathymetric and security missions performed in river and at seas.
- Forest fire detection with a small fixed wing autonomous aerial vehiclePublication . Martins, Alfredo; Almeida, José; Almeida, Carlos; Figueiredo, André; Santos, Filipe; Bento, Domingos; Silva, Hugo; Silva, EduardoIn this work a forest fire detection solution using small autonomous aerial vehicles is proposed. The FALCOS unmanned aerial vehicle developed for remote-monitoring purposes is described. This is a small size UAV with onboard vision processing and autonomous flight capabilities. A set of custom developed navigation sensors was developed for the vehicle. Fire detection is performed through the use of low cost digital cameras and near-infrared sensors. Test results for navigation and ignition detection in real scenario are presented.
- 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.
- Autonomous Surface Vehicle Docking Manoeuvre with Visual InformationPublication . Martins, Alfredo; Almeida, José Miguel; Ferreira, Hugo; Silva, Hugo; Dias, Nuno; Silva, EduardoThis work presents a hybrid coordinated manoeuvre for docking an autonomous surface vehicle with an autonomous underwater vehicle. The control manoeuvre uses visual information to estimate the AUV relative position and attitude in relation to the ASV and steers the ASV in order to dock with the AUV. The AUV is assumed to be at surface with only a small fraction of its volume visible. The system implemented in the autonomous surface vehicle ROAZ, developed by LSA-ISEP to perform missions in river environment, test autonomous AUV docking capabilities and multiple AUV/ASV coordinated missions is presented. Information from a low cost embedded robotics vision system (LSAVision), along with inertial navigation sensors is fused in an extended Kalman filter and used to determine AUV relative position and orientation to the surface vehicle The real time vision processing system is described and results are presented in operational scenario.
- ROAZ and ROAZ II Autonomous Surface Vehicle Design and ImplementationPublication . Martins, Alfredo; Ferreira, Hugo; Almeida, Carlos; Silva, Hugo; Almeida, José Miguel; Silva, EduardoThe design and implementation of the ROAZ and ROAZ II autonomous surface vehicles (ASV) is presented. These systems were developed at Autonomous Systems Lab, ISEP/IPP – Instituto Superior de Engenharia do Porto under a research program in marine robotics. With multiple applications either in river and estuarine environments or in the sea, the system applications in search and rescue operations are addressed and were taken in consideration for the overall system design. Mechanical design issues are discussed. Hardware, software and implementation status are described along with the control and navigation system architecture. The real time vision processing system is described and results are presented in operational scenario.