Percorrer por autor "Teixeira, Marco"
A mostrar 1 - 4 de 4
Resultados por página
Opções de ordenação
- Adaptive path planning for fusing rapidly exploring random trees and deep reinforcement learning in an agriculture dynamic environment UAVsPublication . Castro, Gabriel G.R.; Berger, Guido; Cantieri, Álvaro R.; Teixeira, Marco; Lima, José; Pereira, Ana I.; Pinto, Milena F.Unmanned aerial vehicles (UAV) are a suitable solution for monitoring growing cultures due to the possibility of covering a large area and the necessity of periodic monitoring. In inspection and monitoring tasks, the UAV must find an optimal or near-optimal collision-free route given initial and target positions. In this sense, path-planning strategies are crucial, especially online path planning that can represent the robot’s operational environment or for control purposes. Therefore, this paper proposes an online adaptive path-planning solution based on the fusion of rapidly exploring random trees (RRT) and deep reinforcement learning (DRL) algorithms applied to the generation and control of the UAV autonomous trajectory during an olive-growing fly traps inspection task. The main objective of this proposal is to provide a reliable route for the UAV to reach the inspection points in the tree space to capture an image of the trap autonomously, avoiding possible obstacles present in the environment. The proposed framework was tested in a simulated environment using Gazebo and ROS. The results showed that the proposed solution accomplished the trial for environments up to 300 m3 and with 10 dynamic objects.
- Composição e abundância de macrófitas num troço do rio OvelhaPublication . Andrade, Alexandre; Azevedo, Francisca; Bessa, Catarina; Brás, Maria João; Carneiro, Tomás; Cerqueira, Maria Margarida; Geraldes, Inês; Leal, Sofia; Marinho, Ana Sofia; Monteiro, Ana Carolina; Monteiro, Nicole; Moreira, João; Nascimento, Ana Carolina; Pereira, Ilda; Pinheiro, Maria Eduarda; Pinto, Ana Rita Ferreira Leite; Pinto, David; Pinto, Fátima Raquel; Proença, André; Rangel, Tiago; Ribeiro, Teresa; Ricardo, Maria Jacinta; Rocha, Lara; Rocha, Tiago; Silva, Jéssica; Silva, Rafael; Silva, Tânia Cristina; Soares, Rui; Teixeira, Liliana; Teixeira, Marco; Teixeira, Maria Inês; Pimenta, Sofia Pimenta SaloméAs macrófitas fluviais são um grupo relevante para a avaliação ecológica dos rios. Numa amostragem realizada num troço de 100 m do rio Ovelha, localizado a 217 m de altitude, na freguesia de Fornos, Marco de Canaveses, estudou-se a abundância, composição e distribuição das macrófitas. Verificou-se que o troço estudado é pobre em macrófitas, apresentando uma riqueza específica baixa, o que poderá estar relacionado, sobretudo, com o substrato rochoso. Considerando os resultados obtidos é fundamental que, futuramente, sejam estudadas as macrófitas conjuntamente com outros elementos biológicos, no sentido de se proceder a uma correta monitorização do estado ecológico do rio Ovelha.
- Cooperative heterogeneous robots for autonomous insects trap monitoring system in a precision agriculture scenarioPublication . Berger, Guido; Teixeira, Marco; Cantieri, Álvaro R.; Lima, José; Pereira, Ana I.; Valente, António; Castro, Gabriel G.R.; Pinto, Milena F.The recent advances in precision agriculture are due to the emergence of modern robotics systems. For instance, unmanned aerial systems (UASs) give new possibilities that advance the solution of existing problems in this area in many different aspects. The reason is due to these platforms’ ability to perform activities at varying levels of complexity. Therefore, this research presents a multiple-cooperative robot solution for UAS and unmanned ground vehicle (UGV) systems for their joint inspection of olive grove inspect traps. This work evaluated the UAS and UGV vision-based navigation based on a yellow fly trap fixed in the trees to provide visual position data using the You Only Look Once (YOLO) algorithms. The experimental setup evaluated the fuzzy control algorithm applied to the UAS to make it reach the trap efficiently. Experimental tests were conducted in a realistic simulation environment using a robot operating system (ROS) and CoppeliaSim platforms to verify the methodology’s performance, and all tests considered specific real-world environmental conditions. A search and landing algorithm based on augmented reality tag (AR-Tag) visual processing was evaluated to allow for the return and landing of the UAS to the UGV base. The outcomes obtained in this work demonstrate the robustness and feasibility of the multiple-cooperative robot architecture for UGVs and UASs applied in the olive inspection scenario.
- Fire protection efficiency of intumescent coatingsPublication . Mesquita, L.M.R.; Teixeira, Marco; Piloto, P.A.G.; Barreira, LuísaThis paper presents an experimental study about the fire protection efficiency of a material produced of an emulsion of intumescent coating with granulated cork. The analysis is performed at the micro scale level, with TG and DSC tests at elevated temperatures, and in a mass loss calorimeter with protected steel plates, with temperatures representative of a fire scenario. The results indicate that an increased protection is obtained when the granular cork particle size is smaller and a cork mass fraction of 5% is used.