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Publications

Publications by Nuno Miguel Ferreira

2024

Vision System for a Forestry Navigation Machine

Authors
Pereira, T; Gameiro, T; Pedro, J; Viegas, C; Ferreira, NMF;

Publication
SENSORS

Abstract
This article presents the development of a vision system designed to enhance the autonomous navigation capabilities of robots in complex forest environments. Leveraging RGBD and thermic cameras, specifically the Intel RealSense 435i and FLIR ADK, the system integrates diverse visual sensors with advanced image processing algorithms. This integration enables robots to make real-time decisions, recognize obstacles, and dynamically adjust their trajectories during operation. The article focuses on the architectural aspects of the system, emphasizing the role of sensors and the formulation of algorithms crucial for ensuring safety during robot navigation in challenging forest terrains. Additionally, the article discusses the training of two datasets specifically tailored to forest environments, aiming to evaluate their impact on autonomous navigation. Tests conducted in real forest conditions affirm the effectiveness of the developed vision system. The results underscore the system's pivotal contribution to the autonomous navigation of robots in forest environments.

2024

Evaluation of Different Filtering Methods Devoted to Magnetometer Data Denoising

Authors
Pereira, T; Santos, V; Gameiro, T; Viegas, C; Ferreira, N;

Publication
ELECTRONICS

Abstract
In this article, we describe a performance comparison conducted between several digital filters intended to mitigate the intrinsic noise observed in magnetometers. The considered filters were used to smooth the control signals derived from the magnetometers, which were present in an autonomous forestry machine. Three moving average FIR filters, based on rectangular Bartlett and Hanning windows, and an exponential moving average IIR filter were selected and analyzed. The trade-off between the noise reduction factor and the latency of the proposed filters was also investigated, taking into account the crucial importance of latency on real-time applications and control algorithms. Thus, a maximum latency value was used in the filter design procedure instead of the usual filter order. The experimental results and simulations show that the linear decay moving average (LDMA) and the raised cosine moving average (RCMA) filters outperformed the simple moving average (SMA) and the exponential moving average (EMA) in terms of noise reduction, for a fixed latency value, allowing a more accurate heading angle calculation and position control mechanism for autonomous and unmanned ground vehicles (UGVs).

2024

Incorporating an Intelligent System Based on a Quantum Algorithm into Predictive Analysis for Screening COVID-19 Patients

Authors
Saraiva, AA; da Silva, JPO; Moura Sousa, JV; Fonseca Ferreira, NM; Soares, SP; Valente, A;

Publication
Proceedings of the 17th International Joint Conference on Biomedical Engineering Systems and Technologies, BIOSTEC 2024, Volume 1, Rome, Italy, February 21-23, 2024.

Abstract

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