Joao Sequeira

Prof. Joao Sequeira

Instituto Superior Técnico, Lisbon University, 1649-004 Lisboa, Portugal
orcid

Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 November 2013 in Sensors
Verified
Journal Article
Open access
PDF file
FAFernando Alonso-Martín
Fernando Alonso-Martín
Maria MalfazMaria Malfaz
Maria Malfaz
Joao SequeiraJoao Sequeira
Joao Sequeira
JGJavier F. Gorostiza
Javier F. Gorostiza
MSMiguel A. Salichs
Miguel A. Salichs
In this paper, a multimodal user-emotion detection system for social robots is presented. This system is intended to be used during human–robot interaction, and it is integrated as part of the overall interaction system of the robot: the Robotics Dialog System (RDS). Two modes are used to detect emotions: the voice and face expression analysis. In order to analyze the voice of the user, a new component has been developed: Gender and Emotion Voice Analysis (GEVA), which is written using the Chuck language. For emotion detection in facial expressions, the system, Gender and Emotion Facial Analysis (GEFA), has been also developed. This last system integrates two third-party solutions: Sophisticated High-speed Object Recognition Engine (SHORE) and Computer Expression Recognition Toolbox (CERT). Once these new components (GEVA and GEFA) give their results, a decision rule is applied in order to combine the information given by both of them. The result of this rule, the detected emotion, is integrated into the dialog system through communicative acts. Hence, each communicative act gives, among other things, the detected emotion of the user to the RDS so it can adapt its strategy in order to get a greater satisfaction degree during the human–robot dialog. Each of the new components, GEVA and GEFA, can also be used individually. Moreover, they are integrated with the robotic control platform ROS (Robot Operating System). Several experiments with real users were performed to determine the accuracy of each component and to set the final decision rule. The results obtained from applying this decision rule in these experiments show a high success rate in automatic user emotion recognition, improving the results given by the two information channels (audio and visual) separately.

1 May 2014
Verified
Conference Paper
Closed access
JMJoao Messias
Joao Messias
Rodrigo VenturaRodrigo Ventura
Rodrigo Ventura
Pedro U. LimaPedro U. Lima
Pedro U. Lima
Joao SequeiraJoao Sequeira
Joao Sequeira
PAPaulo Alvito
Paulo Alvito
PCPaulo Carrico
Paulo Carrico
Social Robotics is a rapidly expanding field of research, but long-term results in real-world environments have been limited. The MOnarCH project has the goal of studying the long-term social dynamics of networked robot systems in human environments. In this paper, we present the MOnarCH robotic platform to the research community. We discuss the constraints involved in the design and operation of our social robots, and describe in detail the platform that has been built to accomodate the project goals while satisfying those restrictions. We also present some preliminary results of the navigation methodologies that are used to control the MOnarCH robotic platforms.

19 March 2010 in Sensors
Verified
Journal Article
Open access
PDF file
ASAlberto Sanfeliu
Alberto Sanfeliu
JAJuan Andrade-Cetto
Juan Andrade-Cetto
MBMarco Barbosa
Marco Barbosa
RBRichard Bowden
Richard Bowden
JCJesús Capitán
Jesús Capitán
MSMatthijs T. J. Spaan
Matthijs T. J. Spaan
In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted.

10 September 2019
Verified
Book Chapter
Closed access
PDF file
HAHande Ayanoglu
Hande Ayanoglu
Joao SequeiraJoao Sequeira
Joao Sequeira

25 April 2011 in IEEE Transactions on Instrumentation and Measurement
Verified
Journal Article
Closed access
Joao SequeiraJoao Sequeira
Joao Sequeira
Antonios TsourdosAntonios Tsourdos
Antonios Tsourdos
SLSamuel B. Lazarus
Samuel B. Lazarus
This paper addresses the robust estimation of a covariance matrix to express uncertainty when fusing information from multiple sensors. This is a problem of interest in multiple domains and applications, namely, in robotics. This paper discusses the use of estimators using explicit measurements from the sensors involved versus estimators using only covariance estimates from the sensor models and navigation systems. Covariance intersection and a class of orthogonal Gnanadesikan-Kettenring estimators are compared using the 2-norm of the estimates. A Monte Carlo simulation of a typical mapping experiment leads to conclude that covariance estimation systems with a hybrid of the two estimators may yield the best results.

1 October 2009
Verified
Conference Paper
Closed access
MBMarco Barbosa
Marco Barbosa
Alexandre BernardinoAlexandre Bernardino
Alexandre Bernardino
DFDario Figueira
Dario Figueira
JGJose Gaspar
Jose Gaspar
NGNelson Goncalves
Nelson Goncalves
Joao SequeiraJoao Sequeira
Joao Sequeira
This paper introduces a testbed for sensor and robot network systems, currently composed of 10 cameras and 5 mobile wheeled robots equipped with several sensors for self-localization, obstacle avoidance and vision cameras, and wireless communications. The testbed includes a service-oriented middleware to enable fast prototyping and implementation of algorithms previously tested in simulation, as well as to simplify integration of subsystems developed by different partners. We survey an integrated approach to human-robot interaction that has been developed supported by the testbed under an European research project. The application integrates innovative methods and algorithms for people tracking and waving detection, cooperative perception among static and mobile cameras to improve people tracking accuracy, as well as decision-theoretical approaches to sensor selection and task allocation within the sensor network.