Percorrer por autor "Bento, Luís Conde"
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- Intelligent traffic management at intersections: Legacy mode for vehicles not equipped with V2V and V2I communicationsPublication . Bento, Luís Conde; Parafita, Ricardo; Santos, Sergio; Nunes, UrbanoThis paper describes a legacy algorithm for an intelligent traffic management system applied to automatic regulation of traffic at intersections. The application of the legacy algorithm enables the intelligent intersection to accommodate vehicles, in a low percentage, not equipped or with faulty V2V and V2I communications. The developed intelligent traffic management techniques, which are based on a spatiotemporal reservation scheme, aim to minimize accidents, traffic congestion and consequently the environmental costs of road traffic. The performance of three intelligent traffic management algorithms applied to road intersections, roundabouts and crossroads, are analyzed. Compared with traditional traffic management techniques, simulation results using the developed intelligent traffic management techniques, show that the traffic output flux can be increased, traffic flow rate can be higher and the average time to cross intersections can be significantly reduced. This reduction is more pronounced when the traffic flow is heavy. The conducted studies show that the inclusion of a low percentage of vehicles, not equipped or with faulty V2V and V2I communications, in intelligent intersections using the legacy algorithm, have a low impact on the traffic flow. © 2013 IEEE.
- Monocular Camera Calibration for Autonomous Driving — a comparative studyPublication . Martins, Pedro Filipe; Costelha, Hugo; Bento, Luís Conde; Neves, CarlosAutonomous driving is currently a widely researched topic worldwide. With a large research effort being taken by industrial research units in the automotive sector, it is no longer exclusive to academic research labs. Essential to this ongoing effort towards level-5 vehicle autonomy, are the sensors used for tracking and detection, mainly lasers, radars and cameras. Most of the cameras for automotive application systems use wide-angle or fish-eye lens, which present high distortion levels. Cameras need to be calibrated for correct perception, particularly for capturing geometry features, or for distance-based calculations. This paper describes a case-study concerning monocular camera calibration for a small scale autonomous driving vehicle vision system. It describes the fundamentals on camera calibration and implementation, with results given for different lenses and distortion models. The aim of the paper is not only to provide a detailed and comprehensive review on the application of these calibration methods, but to serve also as a reference document for other researchers and developers starting to use monocular vision in their robotic applications.
- Special Issue on ICARSC 2018Publication . Costelha, Hugo; Calado, João; Bento, Luís Conde; Oliveira, PauloDear colleagues and readers: We are pleased to present you this special issue, bringing you the most relevant papers describing work whose roots were initially published in ICARSC2018, an international conference held every year in Portugal, together with a Robotics competition, promoting and discussing Autonomous Robot Systems and Competitions. The conference had 42 accepted papers from 21 countries in six continents, reviewed by 85 committee members, from 22 countries.
- A study of the environmental impacts of intelligent automated vehicle control at intersections via V2V and V2I communicationsPublication . Bento, Luís Conde; Parafita, Ricardo; Rakha, Hesham A.; Nunes, Urbano J.This article presents a novel intersection traffic management system for automated vehicles and quantifies its impact on fuel consumption and greenhouse gas emissions of CO2 relative to traditional traffic signal and roundabout intersection control. The developed intelligent traffic management (ITM) techniques, which are based on a spatiotemporal reservation scheme, ensure that vehicles proceed through the intersection without colliding with other vehicles while at the same time reducing the intersection delay and environmental impacts. Specifically, the spatiotemporal reservation scheme provides each vehicle a collision-free path that is decomposed into a speed profile along with navigational instructions. The integration of the developed microscopic traffic simulator with instantaneous emission model, provides improved assessments of the environmental impact of traffic control strategies at intersections. The simulator architecture integrates several ITM algorithms, vehicle sensors, V2V/V2I communications, and emission and fuel consumption models. Each vehicle is modeled by an agent and each agent provides information depending on the specific vehicle sensors. The ITM system is supported by V2V and V2I communications, allowing the exchange of information among vehicles and infrastructure. The data include the estimated vehicle position and speed. Compared with traditional traffic management techniques, the simulation results prove that the proposed ITM system reduces CO2 emissions significantly. The research also shows that these reductions are more significant when the traffic flow increases.
- Subjective Evaluation of Haptic Feedback Technologies for Interactive MultimediaPublication . Silva, Bruno; Costelha, Hugo; Bento, Luís Conde; Barata, Márcio; Assunção, Pedro A. AmadoCurrent trends in the development of remote control devices for user interaction with multimedia equipment and applications are increasingly advancing the traditional keypad-based technologies, in order to improve the functionality of remote control devices and also to enhance the user experience. Haptic feedback allows the user to have a similar sensation to that provided by conventional buttons, with the advantage of a much greater flexibility, including dynamic choice of mechanical effects capable of discriminating between different functions. However, selection of haptic feedback effects that are capable of enhancing the user experience remains a great challenge for engineers and product designers. This work is a contribution towards this goal by presenting a usability study of two technologies (eccentric rotating mass and linear resonant actuator) capable of providing different haptic feedback effects in remote control devices. A subjective evaluation study was carried out to obtain subjective scores for a significant number of haptic feedback effects. The number of preferred actuators of each type and whether haptic feedback is suitable in remote control devices for interactive multimedia, were also evaluated. The results of this study show that most users prefer an interface with haptic feedback and different scores were obtained for different haptic feedback effects, according to the characteristics and number of the actuators.