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This service develops advanced solutions in automation and industrial robotics, including handlers and mobile robots, and promotes the integration of control intelligent systems and sensing.

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Browsing CRIIS by Author "5674"
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    A* Based Routing and Scheduling Modules for Multiple AGVs in an Industrial Scenario
    ( 2021) Santos,J ; Paulo Miranda Rebelo ; Luís Freitas Rocha ; Pedro Gomes Costa ; Germano Veiga ; 5159 ; 5364 ; 5674 ; 7077
    A multi-AGV based logistic system is typically associated with two fundamental problems, critical for its overall performance: the AGV’s route planning for collision and deadlock avoidance; and the task scheduling to determine which vehicle should transport which load. Several heuristic functions can be used according to the application. This paper proposes a time-based algorithm to dynamically control a fleet of Autonomous Guided Vehicles (AGVs) in an automatic warehouse scenario. Our approach includes a routing algorithm based on the A* heuristic search (TEA*—Time Enhanced A*) to generate free-collisions paths and a scheduling module to improve the results of the routing algorithm. These modules work cooperatively to provide an efficient task execution time considering as basis the routing algorithm information. Simulation experiments are presented using a typical industrial layout for 10 and 20 AGVs. Moreover, a comparison with an alternative approach from the state-of-the-art is also presented.
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    Applying Software Static Analysis to ROS: The Case Study of the FASTEN European Project
    ( 2019) Neto,T ; Germano Veiga ; André Filipe Santos ; Armando Sousa ; Rafael Lírio Arrais ; 5674 ; 5152 ; 6414 ; 6551
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    Automatic generation of disassembly sequences and exploded views from solidworks symbolic geometric relationships
    ( 2018) Carlos Miguel Costa ; Thomas,U ; Cardoso,HL ; Oliveira,EC ; Luís Freitas Rocha ; Armando Sousa ; Germano Veiga ; 6164 ; 5152 ; 5364 ; 5674
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    Autonomous Robot Navigation for Automotive Assembly Task: An Industry Use-Case
    ( 2019) Héber Miguel Sobreira ; Germano Veiga ; António Paulo Moreira ; Rodrigues,F ; Lima,J ; Luís Freitas Rocha ; 5364 ; 5424 ; 5674 ; 5157
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    Bridging Automation and Robotics: an Interprocess Communication between IEC 61131-3 and ROS
    ( 2018) Pinto,T ; Rafael Lírio Arrais ; Germano Veiga ; 5674 ; 6551
    The contemporary adoption of Cyber-Physical Systems and improvements in robotic applications in industrial scenarios demands for horizontal integration mechanisms with already existing automation equipment, controlled by PLCs. This paper aims to shorten the gap between the automation and robotics domain, by proposing an Interprocess Communication method to establish interoperability between robotic systems and automation equipment in a reliable and straightforward manner. In particular, this paper introduces a novel approach for linking ROS and IEC 61131-3 by way of shared memory interfaces, enabling and promoting their interactions. Moreover, this paper addresses the applied synchronization mechanism for handling concurrent accesses to the shared memory location, explores data type mapping between ROS and IEC 61131-3, and identifies some practical industrial applications.
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    Collaborative Welding System using BIM for Robotic Reprogramming and Spatial Augmented Reality
    ( 2019) Carlos Miguel Costa ; Luís Freitas Rocha ; Malaca,P ; Pedro Gomes Costa ; António Paulo Moreira ; Tavares,P ; Armando Sousa ; Germano Veiga ; 6164 ; 5152 ; 5157 ; 5159 ; 5364 ; 5674
    The optimization of the information flow from the initial design and through the several production stages plays a critical role in ensuring product quality while also reducing the manufacturing costs. As such, in this article we present a cooperative welding cell for structural steel fabrication that is capable of leveraging the Building Information Modeling (BIM) standards to automatically orchestrate the necessary tasks to be allocated to a human operator and a welding robot moving on a linear track. We propose a spatial augmented reality system that projects alignment information into the environment for helping the operator tack weld the beam attachments that will be later on seam welded by the industrial robot. This way we ensure maximum flexibility during the beam assembly stage while also improving the overall productivity and product quality since the operator no longer needs to rely on error prone measurement procedures and he receives his tasks through an immersive interface, relieving him from the burden of analyzing complex manufacturing design specifications. Moreover, no expert robotics knowledge is required to operate our welding cell because all the necessary information is extracted from the Industry Foundation Classes (IFC), namely the CAD models and welding sections, allowing our 3D beam perception systems to correct placement errors or beam bending, which coupled with our motion planning and welding pose optimization system ensures that the robot performs its tasks without collisions and as efficiently as possible while maximizing the welding quality. © 2019 Elsevier B.V.
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    Detecting and Solving Tube Entanglement in Bin Picking Operations
    ( 2020) Carlos Miguel Costa ; Leão,G ; Sousa,A ; Germano Veiga ; 5674 ; 6164
    Manufacturing and production industries are increasingly turning to robots to carry out repetitive picking operations in an efficient manner. This paper focuses on tackling the novel challenge of automating the bin picking process for entangled objects, for which there is very little research. The chosen case study are sets of freely curved tubes, which are prone to occlusions and entanglement. The proposed algorithm builds a representation of the tubes as an ordered list of cylinders and joints using a point cloud acquired by a 3D scanner. This representation enables the detection of occlusions in the tubes. The solution also performs grasp planning and motion planning, by evaluating post-grasp trajectories via simulation using Gazebo and the ODE physics engine. A force/torque sensor is used to determine how many items were picked by a robot gripper and in which direction it should rotate to solve cases of entanglement. Real-life experiments with sets of PVC tubes and rubber radiator hoses showed that the robot was able to pick a single tube on the first try with success rates of 99% and 93%, respectively. This study indicates that using simulation for motion planning is a promising solution to deal with entangled objects.
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    Force control heuristics for surpassing pose uncertainty in mobile robotic assembly platforms
    ( 2021) Duarte Alão Magalhães ; Paulo Miranda Rebelo ; Carlos Miguel Costa ; Luís Freitas Rocha ; Germano Veiga ; 5364 ; 5674 ; 7077 ; 8275 ; 6164
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    Modeling of video projectors in OpenGL for implementing a spatial augmented reality teaching system for assembly operations
    ( 2019) Rui Pedro Rodrigues ; Thomas,U ; Carlos Miguel Costa ; Germano Veiga ; Armando Sousa ; Luís Freitas Rocha ; Augusto Sousa ; 5674 ; 5364 ; 5152 ; 5579 ; 197 ; 6164
    Teaching complex assembly and maintenance skills to human operators usually requires extensive reading and the help of tutors. In order to reduce the training period and avoid the need for human supervision, an immersive teaching system using spatial augmented reality was developed for guiding inexperienced operators. The system provides textual and video instructions for each task while also allowing the operator to navigate between the teaching steps and control the video playback using a bare hands natural interaction interface that is projected into the workspace. Moreover, for helping the operator during the final validation and inspection phase, the system projects the expected 3D outline of the final product. The proposed teaching system was tested with the assembly of a starter motor and proved to be more intuitive than reading the traditional user manuals. This proof of concept use case served to validate the fundamental technologies and approaches that were proposed to achieve an intuitive and accurate augmented reality teaching application. Among the main challenges were the proper modeling and calibration of the sensing and projection hardware along with the 6 DoF pose estimation of objects for achieving precise overlap between the 3D rendered content and the physical world. On the other hand, the conceptualization of the information flow and how it can be conveyed on-demand to the operator was also of critical importance for ensuring a smooth and intuitive experience for the operator. © 2019 IEEE.
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    Modeling of video projectors in OpenGL for implementing a spatial augmented reality teaching system for assembly operations
    ( 2019) Germano Veiga ; Carlos Miguel Costa ; Rui Pedro Rodrigues ; Augusto Sousa ; Luís Freitas Rocha ; Thomas,U ; Armando Sousa ; 197 ; 5579 ; 5152 ; 5364 ; 5674 ; 6164
    Teaching complex assembly and maintenance skills to human operators usually requires extensive reading and the help of tutors. In order to reduce the training period and avoid the need for human supervision, an immersive teaching system using spatial augmented reality was developed for guiding inexperienced operators. The system provides textual and video instructions for each task while also allowing the operator to navigate between the teaching steps and control the video playback using a bare hands natural interaction interface that is projected into the workspace. Moreover, for helping the operator during the final validation and inspection phase, the system projects the expected 3D outline of the final product. The proposed teaching system was tested with the assembly of a starter motor and proved to be more intuitive than reading the traditional user manuals. This proof of concept use case served to validate the fundamental technologies and approaches that were proposed to achieve an intuitive and accurate augmented reality teaching application. Among the main challenges were the proper modeling and calibration of the sensing and projection hardware along with the 6 DoF pose estimation of objects for achieving precise overlap between the 3D rendered content and the physical world. On the other hand, the conceptualization of the information flow and how it can be conveyed on-demand to the operator was also of critical importance for ensuring a smooth and intuitive experience for the operator.
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    On the development of a collaborative robotic system for industrial coating cells
    ( 2021) Rafael Lírio Arrais ; Carlos Miguel Costa ; Ribeiro,P ; Luís Freitas Rocha ; Manuel Santos Silva ; Germano Veiga ; 5364 ; 6164 ; 6551 ; 5655 ; 5674
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    Online inspection system based on machine learning techniques: real case study of fabric textures classification for the automotive industry
    ( 2019) Luís Freitas Rocha ; Malaca,P ; Germano Veiga ; Silva,J ; Gomes,D ; 5364 ; 5674
    This paper focus on the classification, in real-time and under uncontrolled lighting, of fabric textures for the automotive industry. Many industrial processes have spatial constraints that limit the effective control of illumination of their vision based systems, hindering their effectiveness. The ability to overcome these problems using robust classification methods with suitable pre-processing techniques and choice of characteristics will increase the efficiency of this type of solutions with obvious production gains and thus economical. For this purpose, this paper studied and analyzed various pre-processing techniques, and selected the most appropriate fabric characteristics for the considered industrial case scenario. The methodology followed was based on the comparison of two different machine learning classifiers, ANN and SVM, using a large set of samples with a large variability of lightning conditions to faithfully simulate the industrial environment. The obtained solution shows the sensibility of ANN over SVM considering the number of features and the size of the training set, showing the better effectiveness and robustness of the last. The characteristics vector uses histogram equalization, Laws filter and Sobel filter, and multi-scale analysis. By using a correlation based method was possible to reduce the number of features used, achieving a better balanced between processing time and classification ratio. © 2016 Springer Science+Business Media New York
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    Perception of Entangled Tubes for Automated Bin Picking
    ( 2019) Carlos Miguel Costa ; Germano Veiga ; Armando Sousa ; Leão,G ; 5674 ; 6164 ; 5152