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Sobre

Sobre

Investigador em robótica subaquática. Mais informações em http://oceansys.fe.up.pt/

Tópicos
de interesse
Detalhes

Detalhes

  • Nome

    Nuno Cruz
  • Cargo

    Coordenador de Centro
  • Desde

    01 junho 2009
023
Publicações

2023

Model Identification and Control of a Buoyancy Change Device

Autores
Carneiro, JF; Pinto, JB; de Almeida, FG; Cruz, NA;

Publicação
ACTUATORS

Abstract
There are several compelling reasons for exploring the ocean, for instance, the potential for accessing valuable resources, such as energy and minerals; establishing sovereignty; and addressing environmental issues. As a result, the scientific community has increasingly focused on the use of autonomous underwater vehicles (AUVs) for ocean exploration. Recent research has demonstrated that buoyancy change modules can greatly enhance the energy efficiency of these vehicles. However, the literature is scarce regarding the dynamic models of the vertical motion of buoyancy change modules. It is therefore difficult to develop adequate depth controllers, as this is a very complex task to perform in situ. The focus of this paper is to develop simplified linear models for a buoyancy change module that was previously designed by the authors. These models are experimentally identified and used to fine-tune depth controllers. Experimental results demonstrate that the controllers perform well, achieving a virtual zero steady-state error with satisfactory dynamic characteristics.

2023

Estimation of Sediments in Underwater Wall Corners using a Mechanical Scanning Sonar

Autores
Goncalves, CF; Cruz, NA; Ferreira, BM;

Publicação
2023 IEEE International Symposium on Underwater Technology, UT 2023

Abstract
This paper describes a robotic system to detect and estimate the volume of sediments in underwater wall corners, in scenarios with zero visibility. All detection and positioning is based on data from a scanning sonar. The main idea is to scan the walls and the bottom of the structure to detect the corner, and then use data obtained in the direction of the corner to estimate the presence of sediment accumulation and its volume. Our approach implements an image segmentation to extract range from the surfaces of interest. The resulting data is then employed for relative localization and estimate of the sediment accumulation. The paper provides information about the methodologies developed and data from practical experiments. © 2023 IEEE.

2023

Single Receiver Underwater Localization of an Unsynchronized Periodic Acoustic Beacon Using Synthetic Baseline

Autores
Ferreira, BM; Graça, PA; Alves, JC; Cruz, NA;

Publicação
IEEE JOURNAL OF OCEANIC ENGINEERING

Abstract
This article addresses the 3-D localization of a stand-alone acoustic beacon based on the Principle of Synthetic Baseline using a single receiver on board a surface vehicle. The process only uses the passive reception of an acoustic signal with no explicit synchronization, interaction, or communication with the acoustic beacon. The localization process exploits the transmission of periodic signals without synchronization to a known time reference to estimate the time-of-arrival (ToA) with respect to an absolute time basis provided by the global navigation satellite system (GNSS). We present the development of the acoustic signal acquisition system, the signal processing algorithms, the data processing of times-of-arrival, and an estimator that uses times-of-arrival and the coordinates where they have been collected to obtain the 3-D position of the acoustic beacon. The proposed approach was validated in a real field application on a search for an underwater glider lost in September 2021 near the Portuguese coast.

2023

Estimation of Sediments in Underwater Wall Corners using a Mechanical Scanning Sonar

Autores
Goncalves, CF; Cruz, NA; Ferreira, BM;

Publicação
2023 IEEE UNDERWATER TECHNOLOGY, UT

Abstract
This paper describes a robotic system to detect and estimate the volume of sediments in underwater wall corners, in scenarios with zero visibility. All detection and positioning is based on data from a scanning sonar. The main idea is to scan the walls and the bottom of the structure to detect the corner, and then use data obtained in the direction of the corner to estimate the presence of sediment accumulation and its volume. Our approach implements an image segmentation to extract range from the surfaces of interest. The resulting data is then employed for relative localization and estimate of the sediment accumulation. The paper provides information about the methodologies developed and data from practical experiments.

2023

TEC4SEA-Developing maritime technology for a sustainable blue economy

Autores
Monica, P; Cruz, N; Almeida, JM; Silva, A; Silva, E; Pinho, C; Almeida, C; Viegas, D; Pessoa, LM; Lima, AP; Martins, A; Zabel, F; Ferreira, BM; Dias, I; Campos, R; Araujo, J; Coelho, LC; Jorge, PS; Mendes, J;

Publicação
OCEANS 2023 - LIMERICK

Abstract
One way to mitigate the high costs of doing science or business at sea is to create technological infrastructures possessing all the skills and resources needed for successful maritime operations, and make those capabilities and skills available to the external entities requiring them. By doing so, the individual economic and scientific agents can be spared the enormous effort of creating and maintaining their own, particular set of equivalent capabilities, thus drastically lowering their initial operating costs. In addition to cost savings, operating based on fully-fledged, shared infrastructures not only allows the use of more advanced scientific equipment and highly skilled personnel, but it also enables the business teams (be it industry or research) to focus on their goals, rather than on equipment, logistics, and support. This paper will describe the TEC4SEA infrastructure, created precisely to operate as described. This infrastructure has been under implementation in the last few years, and has now entered its operational phase. This paper will describe it, present its current portfolio of services, and discuss the most relevant assets and facilities that have been recently acquired, so that the research and industrial communities requiring the use of such assets can fully evaluate their adequacy for their own purposes and projects.

Teses
supervisionadas

2022

Otimização do Desempenho de Redes Neuronais em Sistemas Embarcados

Autor
João António de Brito Ferreira Gonçalves

Instituição
UP-FEUP

2022

Adaptive close-range navigation for inspection pf underwater structures

Autor
Ana Rita da Silva Gaspar

Instituição
UP-FEUP

2022

Incremental Approach for Automatic Generation of Domain Specific Sentiment Lexicon

Autor
Shamsuddeen Hassan Muhammad

Instituição
UP-FEUP

2022

Autonomous Optimization for a Transactional Middleware

Autor
Susana Vitória Sá Silva Marques

Instituição
UM

2022

On the performance of WebAssembly

Autor
João Gonçalves de Macedo

Instituição
UM