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Publications

Publications by CRAS

2017

Collision Avoidance for Safe Structure Inspection with Multirotor UAV

Authors
Azevedo, F; Oliveira, A; Dias, A; Almeida, J; Moreira, M; Santos, T; Ferreira, A; Martins, A; Silva, E;

Publication
2017 EUROPEAN CONFERENCE ON MOBILE ROBOTS (ECMR)

Abstract
The multirotor UAVs are being integrated into a wide range of application scenarios due to maneuverability in 3D, versatility and reasonable payload of sensors. One of the application scenarios is the inspection of structures where the human intervention is difficult or unsafe and the UAV can provide an improvement of the collected data. At the same time introduce challenges due to low altitude missions and also the fact of being manually operated without line of sight. In order to overcome these issues, this paper presents a LiDAR-based realtime collision avoidance algorithm, denoted by Escape Elliptical Search Point with the ability to be integrated into autonomous and manned modes of operation. The algorithm was validated in a simulation environment developed in Gazebo and also in a mixed environment composed by a real robot in an outdoor scenario and simulated obstacle and LiDAR.

2017

Fish Farming Autonomous Calibration System

Authors
Lopes, F; Silva, H; Almeida, JM; Pinho, C; Silva, E;

Publication
OCEANS 2017 - ABERDEEN

Abstract
The fish farming industry is becoming widespread all over the world. By 2039 most of the fish we eat will come from the fish farming industry. In this work, we propose an autonomous robotic solution for indoor fish farming biomass estimation. Our proposed system moves silently on top of the tank borders using differential wheels and a structured light vision system (SLS). The SLS system is composed by a camera and two line lasers (projectors) equipped with a line beam that allows to obtain the fish depth profile present in the tank to perform biomass estimation. Results in laboratory and in real aquaculture environment with live fish are presented.

2017

Simulation Environment for Underground Flooded Mines Robotic Exploration

Authors
Sytnyk, D; Pereira, R; Pedrosa, D; Rodrigues, J; Martins, A; Dias, A; Almeida, J; Silva, E;

Publication
OCEANS 2017 - ABERDEEN

Abstract
Underwater experiments with unmanned vehicles are complex, costly, time-consuming and in some circumstances potentially dangerous, involving the risk of losing or damaging the robots. The nature of the underwater environment, makes it very difficult, for researchers, to observe the evolution of the running system. Simulators are useful tools for the development of unmanned vehicle software, algorithm benchmarking and system preliminary validation. In this work, the problem of simulating a complex underwater scenario for marine robotics and a comparative analysis of simulators for marine robotics are presented. Relevant sensors for underwater robots under development, such as multibeam and imaging 2D sonar were implemented in two simulators and tested in a realistic experimental scenario like a flooded mine.

2017

UAV Cooperative Perception based on DDS communications network

Authors
Ribeiro, JP; Fontes, H; Lopes, M; Silva, H; Campos, R; Almeida, JM; Silva, E;

Publication
OCEANS 2017 - ANCHORAGE

Abstract
This paper focus on the use of unmanned aerial vehicle teams for performing cooperative perception using Data Distribution Service (DDS) Network. We develop a DDS framework to manage the incoming and out bounding network traffic of multiple types of data that is exchanged inside the UAV network. Experimental results both in laboratory and in actual flight are presented to help characterize the proposed system solution.

2017

Autonomous Systems in remote areas of the Ocean using BLUECOM plus communication network

Authors
Ferreira, H; Silva, F; Sousa, P; Matias, B; Faria, A; Oliveira, J; Almeida, JM; Martins, A; Silva, E;

Publication
OCEANS 2017 - ANCHORAGE

Abstract
The authors present a series of sea trails with autonomous systems using a long-range communication network. The continuous monitoring of the oceans and realtime data gathering/monitoring is a key issue in future marine challenges. To have long range communication, between land and ships at tens of kilometers', the authors used the BlueCom+ project research trials and tested their robotic systems. Bluecom+ project intends to fill the gap of long range communication with high bandwidth. It was demonstrated the usefulness of the system using autonomous systems, such as a small unmanned vehicle (ROAZ USV) for bathymetric mapping and tested an underwater acoustic positioning and communications system. © 2017 Marine Technology Society.

2017

Simulation Environment for Underground Flooded Mines Robotic Exploration

Authors
Pereira, R; Rodrigues, J; Martins, A; Dias, A; Almeida, J; Almeida, C; Silva, E;

Publication
2017 IEEE INTERNATIONAL CONFERENCE ON AUTONOMOUS ROBOT SYSTEMS AND COMPETITIONS (ICARSC)

Abstract
This paper presents the work performed in the implementation of an underwater simulation environment for the development of an autonomous underwater vehicle for the exploration of flooded underground tunnels. In particular, the implementation of a laser based structured light system, multibeam sonar and other robot details were addressed. The simulation was used as a relevant tool in order to study and specify the robot multiple sensors characteristics and placement in order to adequately survey a realistic environment. A detailed description of the research and development work is presented along with the analysis of obtained results and the benefits this work brings to the project.

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