Loading...
39 results
Search Results
Now showing 1 - 10 of 39
- Computational intelligence applied to discriminate bee pollen quality and botanical originPublication . Gonçalves, Paulo; Estevinho, Letícia M.; Pereira, Ana Paula; Sousa, João M.C.; Anjos, O.The aim of this work was to develop computational intelligence models based on neural networks (NN), fuzzy models (FM), and support vector machines (SVM) to predict physicochemical composition of bee pollen mixture given their botanical origin. To obtain the predominant plant genus of pollen (was the output variable), based on physicochemical composition (were the input variables of the predictive model), prediction models were learned from data. For the inverse case study, input/output variables were swapped. The probabilistic NN prediction model obtained 98.4% of correct classification of the predominant plant genus of pollen. To obtain the secondary and tertiary plant genus of pollen, the results present a lower accuracy. To predict the physicochemical characteristic of a mixture of bee pollen, given their botanical origin, fuzzy models proven the best results with small prediction errors, and variability lower than 10%.
- Ontological concepts for information sharing in cloud roboticsPublication . Freitas, Edison Pignaton de; Olszewska, Joanna Isabelle; Carbonera, Joel Luis; Fiorini, Sandro; Khamis, Alaa; Ragavan, S. Veera; Barreto, Marcos; Prestes, Edson; Habib, Maki K.; Redfield, Signe; Chibani, Abdelghani; Gonçalves, Paulo; Bermejo-Alonso, Julita; Sanz, Ricardo; Tosello, Elisa; Olivares-Alarcos, Alberto; Konzen, Andrea Aparecida; Quintas, João; Li, HowardRecent research and developments in cloud robotics (CR) require appropriate knowledge representation to ensure interoperable data, information, and knowledge sharing within cloud infrastructures. As an important branch of the Internet of Things (IoT), these demands to advance it forward motivates academic and industrial sectors to invest on it. The IEEE ’Ontologies for Robotics and Automation’ Working Group (ORA WG) has been developing standard ontologies for different robotic domains, including industrial and autonomous robots. The use of such robotic standards has the potential to benefit the Cloud Robotic Community (CRC) as well, supporting the provision of ubiquitous intelligent services by the CR-based systems. This paper explores this potential by developing an ontological approach for effective information sharing in cloud robotics scenarios. It presents an extension to the existing ontological standards to cater for the CR domain. The use of the new ontological elements is illustrated through its use in a couple of CR case studies. To the best of our knowledge, this is the first work ever that implements an ontology comprising concepts and axioms applicable to the CR domain.
- Inspecção visual automática em produtos cerâmicosPublication . Gonçalves, Paulo; Fernandes, Nuno O.; Fernandes, António MarquesA aplicação de um sistema de visão por computador é representada no presente artigo, com o objectivo de automatizar o posto de trabalho de inspecção de produtos cerâmicos, no subsector de pavimentos e revestimentos. O sistema de inspecção apresentado é composto por um sistema de iluminação para garantir luminosidade constante no produto cerâmico a inspeccionar e por um sistema de captura e processamento de imagens a cores. Os algoritmos desenvolvidos para a detecção de defeitos incluem algoritmos de binarização, baseados em análise estatística e morfologia matemática. São apresentados resultados bastante satisfatórios na identificação do defeito grânulo. O sistema realiza ainda o controlo dimensional do mosaico/azulejo, através dos descritores área, largura e comprimento, com uma precisão de décimas de milímetro. O sistema inspecciona de forma automática os defeitos descritos em produtos cerâmicos de padrão uniforme e de uma só cor, tendo sido obtidos resultados bastante satisfatórios para o número de produtos cerâmicos disponibilizados pelas empresas do subsector de pavimentos e revestimentos.
- Towards older adults cognitive and emotional stimulation via robotic cognitive gamesPublication . Cesário, Patrícia; Santos, Samuel; Lourenço, Bernardo; Martins, Inês; Gonçalves, PauloThe paper presents and discusses a framework to promote older adults cognitive and emotional stimulation via Robotic Cognitive Games. The work is based on classic games for older adults, e.g., to place objects in pre-defined positions in an arena, where the authors introduce a robot in the games. The paper not only presents the robotic games, but also the methodology developed to properly introduce them to older adults in a nursing home. As such, the paper proposes three cognitive robotic games, a methodology to assess the success of its introduction to older adults, keeping in mind cognitive and emotional aspects. To validate the proposed robotic solution, experimental tests were performed in a nursing home. A prior cognitive and emotional test was done with older adults to have a ground truth to compare with after a batch of games was completed by each older adult. The results and their discussion validate the robotic games approach, and also the methodology used for its introduction in the nursing home.
- Ontology for autonomous roboticsPublication . Gonçalves, Paulo; Li, Howard; Fiorini, Sandro; Olszewska, Joanna IsabelleCreating a standard for knowledge representation and reasoning in autonomous robotics is an urgent task if we consider recent advances in robotics as well as predictions about the insertion of robots in human daily life. Indeed, this will impact the way information is exchanged between multiple robots or between robots and humans and how they can all understand it without ambiguity. Indeed, Human Robot Interaction (HRI) represents the interaction of at least two cognition models (Human and Robot). Such interaction informs task composition, task assignment, communication, cooperation and coordination in a dynamic environment, requiring a flexible representation. Hence, this paper presents the IEEE RAS Autonomous Robotics (AuR) Study Group, which is a spin-off of the IEEE Ontologies for Robotics and Automation (ORA) Working Group, and its ongoing work to develop the first IEEE-RAS ontology standard for autonomous robotics. In particular, this paper reports on the current version of the ontology for autonomous robotics as well as on its first implementation successfully validated for a human-robot interaction scenario, demonstrating the developed ontology’s strengths which include semantic interoperability and capability to relate ontologies from different fields for knowledge sharing and interactions.
- Knowledge and capabilities representation for visually guided robotic bin pickingPublication . Gonçalves, Paulo; Pinto, J.R. Caldas; Torres, FredericoThe paper presents an implementation of knowledge representation including the capabilities of the system, based on ontologies for a Visually Guided Bin Picking Task. The ontology based approach was used to define the work environment, the robot, the machine vision sys- tem, and the capabilities that are needed to be performed by the robotic system, to perform the bin-picking task. The work proposes a novel application framework that is able to locate the object to pick from the bin and place it in a cell from a kit. For that, the framework, delivers the task implementation (PDDL) files that should be executed by the robot. The method used to detect the objects is based on Chamfer Match (CM) and Oriented Chamfer Match (OCM) which take advantage of the image edge map. To complete the pose estimation problem the robot manipulator is equipped with a laser range finder that can measure the object height. The robotic system was validated experimentally with simulation. using the V-REP environment interfacing with ROS, where the knowledge representation and reasoning framework is implemented. The system showed its capability to correctly pick and place a specific object. Moreover, the ontology based approach was very useful to define the task, the actions to be performed by the robot, based on its capabilities.
- Computer vision intelligent approaches to extract human pose and Its activity from image sequencesPublication . Gonçalves, Paulo; Lourenço, Bernardo; Santos, Samuel; Barlogis, Rodolphe; Misson, AlexandreThe purpose of this work is to develop computational intelligence models based on neural networks (NN), fuzzy models (FM), support vector machines (SVM) and long short-term memory networks (LSTM) to predict human pose and activity from image sequences, based on computer vision approaches to gather the required features. To obtain the human pose semantics (output classes), based on a set of 3D points that describe the human body model (the input variables of the predictive model), prediction models were obtained from the acquired data, for example, video images. In the same way, to predict the semantics of the atomic activities that compose an activity, based again in the human body model extracted at each video frame, prediction models were learned using LSTM networks. In both cases the best learned models were implemented in an application to test the systems. The SVM model obtained 95.97% of correct classification of the six different human poses tackled in this work, during tests in different situations from the training phase. The implemented LSTM learned model achieved an overall accuracy of 88%, during tests in different situations from the training phase. These results demonstrate the validity of both approaches to predict human pose and activity from image sequences. Moreover, the system is capable of obtaining the atomic activities and quantifying the time interval in which each activity takes place.
- Robotic system navigation developed for hip resurfacing prosthesis surgeryPublication . Torres, Pedro; Gonçalves, Paulo; Martins, Jorge M.M.This paper discusses the design of a navigation system developed to assist surgeons in the procedures of Hip Resurfacing prosthesis surgeries. In conventional surgery, mechanical jigs are used to obtain a correct alignment for the metal prosthesis, however it is a very time consuming process. In order to solve this problem emerges a new robotic system, named HipRob. The system is composed by a pre-operative sub-system for planning the prosthesis correct alignment and a flexible robot to be co-manipulated by the surgeon during the drilling procedures on the femur head. The real-time navigation of this robotic system is based on the registration between the femur model, constructed from the CT scan, and the surface constructed with ultrasound images, acquired during the surgical procedures. Experimental results, performed in a femur phantom, show that the robot location errors are around 2 mm.
- Uncalibrated eye-to-hand visual servoing using inverse fuzzy modelsPublication . Gonçalves, Paulo; Mendonça, L.F.; Sousa, João M.C.; Pinto, J.R. CaldasA new uncalibrated eye-to-hand visual servoing based on inverse fuzzy modeling is proposed in this paper. In classical visual servoing, the Jacobian plays a decisive role in the convergence of the controller, as its analytical model depends on the selected image features. This Jacobian must also be inverted online. Fuzzy modeling is applied to obtain an inverse model of the mapping between image feature variations and joint velocities. This approach is independent from the robot's kinematic model or camera calibration and also avoids the necessity of inverting the Jacobian online. An inverse model is identified for the robot workspace, using measurement data of a robotic manipulator. This inverse model is directly used as a controller. The inverse fuzzy control scheme is applied to a robotic manipulator performing visual servoing for random positioning in the robot workspace. The obtained experimental results show the effectiveness of the proposed control scheme. The fuzzy controller can position the robotic manipulator at any point in the workspace with better accuracy than the classic visual servoing approach.
- A review and comparison of ontology-based approaches to robot autonomyPublication . Olivares-Alarcos, Alberto; Beßler, Daniel; Khamis, Alaa; Gonçalves, Paulo; Habib, Maki K.; Bermejo-Alonso, Julita; Barreto, Marcos; Diab, Mohammed; Rosell, Jan; Quintas, João; Olszewska, Joanna Isabelle; Nakawala, Hirenkumar; Pignaton, Edison; Gyrard, Amelie; Borgo, Stefano; Alenyà, Guillem; Beetz, Michael; Li, HowardWithin the next decades, robots will need to be able to execute a large variety of tasks autonomously in a large variety of environments. To relax the resulting programming effort, a knowledge-enabled approach to robot programming can be adopted to organize information in re-usable knowledge pieces. However, for the ease of reuse, there needs to be an agreement on the meaning of terms. A common approach is to represent these terms using ontology languages that conceptualize the respective domain. In this work, we will review projects that use ontologies to support robot autonomy. We will systematically search for projects that fulfill a set of inclusion criteria and compare them with each other with respect to the scope of their ontology, what types of cognitive capabilities are supported by the use of ontologies, and which is their application domain.