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Publications

Publications by António Valente

2021

An Intelligent Predictive Maintenance Approach Based on End-of-Line Test Logfiles in the Automotive Industry

Authors
Vicêncio, D; Silva, H; Soares, S; Filipe, V; Valente, A;

Publication
Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST

Abstract
Through technological advents from Industry 4.0 and the Internet of Things, as well as new Big Data solutions, predictive maintenance begins to play a strategic role in the increasing operational performance of any industrial facility. Equipment failures can be very costly and have catastrophic consequences. In its basic concept, Predictive maintenance allows minimizing equipment faults or service disruptions, presenting promising cost savings. This paper presents a data-driven approach, based on multiple-instance learning, to predict malfunctions in End-of-Line Testing Systems through the extraction of operational logs, which, while not designed to predict failures, contains valid information regarding their operational mode over time. For the case study performed, a real-life dataset was used containing thousands of log messages, collected in a real automotive industry environment. The insights gained from mining this type of data will be shared in this paper, highlighting the main challenges and benefits, as well as good recommendations, and best practices for the appropriate usage of machine learning techniques and analytics tools that can be implemented in similar industrial environments. © 2021, ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering.

2019

Navigation of quadruped multi-robots by gesture recognition using restricted Boltzmann machines

Authors
Saraiva, AA; Santos, DBS; Marques Junior, FCF; Sousa, JVM; Fonseca Ferreira, NM; Valente, A;

Publication
Robotics Transforming the Future - Proceedings of the 21st International Conference on Climbing and Walking Robots and the Support Technologies for Mobile Machines, CLAWAR 2018

Abstract
This article discusses a method that performs gesture recognition, with the objective of extracting characteristics of the segmented hand, from dynamic images captured from a webcam and identifying signal patterns. With this method it is possible to manipulate simulated multirobots that perform specific movements. The method consists of the Continuously Adaptive Mean-SHIFT algorithm, followed by the Threshold segmentation algorithm and Deep Learning through Boltzmann restricted machines. As a result, an accuracy of 82.2%. © CLAWAR Association.

2020

Can NAO Robot Influence the Eye Gaze and Joint Attention of Mentally Impaired Young Adults?

Authors
Freire, A; Valente, A; Filipe, V;

Publication
DSAI 2020: 9th International Conference on Software Development and Technologies for Enhancing Accessibility and Fighting Info-exclusion, Virtual Event, Portugal, December 2-4, 2020.

Abstract

2020

Environment Monitoring Modules with Fire Detection Capability Based on IoT Methodology

Authors
Brito, T; Azevedo, BF; Valente, A; Pereira, AI; Lima, J; Costa, P;

Publication
Science and Technologies for Smart Cities - 6th EAI International Conference, SmartCity360° Virtual Event, December 2-4, 2020, Proceedings

Abstract
Worldwide, forests have been devastated by fires in recent years. Whe- ther by human intervention or for other reasons, the history of burned areas is increasing year after year, degrading fauna and flora. For this reason, it is vital to detect an early ignition so that firefighters can act quickly, reducing the impacts caused by forest fires. The proposed system aims to improve the nature monitoring and to assist the existing surveillance systems through Wireless Sensor Network. The network formed by the set of sensors has the potential to identify forest ignitions and, consequently, alerts the authorities through LoRaWAN communication. This work presents a prototype based on low-cost technology, which can be used in areas that require a high density of modules. Tests with a Wireless Sensor Network made up of nine prototypes demonstrate its effectiveness and robustness in terms of data transmission and collection. In this way, it is possible to apply this approach in Portuguese forests with a high level of forest fire risk, transforming them into Forests 4.0 concept.

2021

A Case Study on Improving the Software Dependability of a ROS Path Planner for Steep Slope Vineyards

Authors
Santos, LC; Santos, A; Santos, FN; Valente, A;

Publication
ROBOTICS

Abstract
Software for robotic systems is becoming progressively more complex despite the existence of established software ecosystems like ROS, as the problems we delegate to robots become more and more challenging. Ensuring that the software works as intended is a crucial (but not trivial) task, although proper quality assurance processes are rarely seen in the open-source robotics community. This paper explains how we analyzed and improved a specialized path planner for steep-slope vineyards regarding its software dependability. The analysis revealed previously unknown bugs in the system, with a relatively low property specification effort. We argue that the benefits of similar quality assurance processes far outweigh the costs and should be more widespread in the robotics domain.

2021

Smarter Robotic Sprayer System for Precision Agriculture

Authors
Baltazar, AR; dos Santos, FN; Moreira, AP; Valente, A; Cunha, JB;

Publication
ELECTRONICS

Abstract
The automation of agricultural processes is expected to positively impact the environment by reducing waste and increasing food security, maximising resource use. Precision spraying is a method used to reduce the losses during pesticides application, reducing chemical residues in the soil. In this work, we developed a smart and novel electric sprayer that can be assembled on a robot. The sprayer has a crop perception system that calculates the leaf density based on a support vector machine (SVM) classifier using image histograms (local binary pattern (LBP), vegetation index, average, and hue). This density can then be used as a reference value to feed a controller that determines the air flow, the water rate, and the water density of the sprayer. This perception system was developed and tested with a created dataset available to the scientific community and represents a significant contribution. The results of the leaf density classifier show an accuracy score that varies between 80% and 85%. The conducted tests prove that the solution has the potential to increase the spraying accuracy and precision.

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