Automobile laser brazing remains a complex process whose results are affected by several process ... more Automobile laser brazing remains a complex process whose results are affected by several process variables that may result in nonacceptable welds. A multisensory customized inspection system is proposed, with two distinct non-destructive techniques: the potential drop method and eddy current testing. New probes were designed, simulated, produced, and experimentally validated in automobile’s laser-brazed weld beads with artificially introduced defects. The numerical simulations allowed the development of a new four-point probe configuration in a non-conventional orthogonal shape demonstrating a superior performance in both simulation and experimental validation. The dedicated inspection system allowed the detection of porosities, cracks, and lack of bonding defects, demonstrating the redundancy and complementarity these two techniques provide.
The International Journal of Advanced Manufacturing Technology, 2021
An innovative pilot installation and eddy current testing (ECT) inspection system for laser-braze... more An innovative pilot installation and eddy current testing (ECT) inspection system for laser-brazed joints is presented. The proposed system detects both surface and sub-surface welding defects operating autonomously and integrated with a robotized arm. Customized eddy current probes were designed and experimentally validated detecting pore defects with 0.13 mm diameter and sub-surface defects buried 1 mm deep. The integration of the system and the manufacturing process towards an Industry 4.0 quality control paradigm is also discussed.
IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society, 2019
In this paper we present a novel strategy and implementation of autonomous navigation for the Pep... more In this paper we present a novel strategy and implementation of autonomous navigation for the Pepper robot. The proposed solution is modular and relies on the proper integration of existing Pepper functionalities. The human interacts with the robot using voice and/or gesture commands to setup the robot functionalities. An example use case demonstrates the ability of the robot to navigate in office environment and grasp an object to place in a target location. The robot is also able to avoid obstacles while navigating.
Tese de doutoramento em Engenharia Mecânica, na especialidade de Controlo e Gestao, apresentada a... more Tese de doutoramento em Engenharia Mecânica, na especialidade de Controlo e Gestao, apresentada ao Departamento de Engenharia Mecânica da Faculdade de Ciencias e Tecnologia da Universidade de Coimbra
IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society, 2019
The use of gestures as interface between humans and robots to facilitate communication between th... more The use of gestures as interface between humans and robots to facilitate communication between them is a long-sought goal. Although many gesture solutions have been presented, none of them cope entirely with wrong gesture recognition. This study proposes a novel electromyography (EMG) prototype sensor to capture gestures and also algorithms and procedures to discriminate data containing valid gestures (segmentation). Gestures are recognized using convolutional neural network (CNN) model. The proposed solution presented high recognition accuracy overcoming other similar studies in literature. Test results demonstrated that the proposed solution presents high performance and suggested its use in industrial environment.
Orientation estimation plays a crucial role in robotics. Precise and reliable estimation of orien... more Orientation estimation plays a crucial role in robotics. Precise and reliable estimation of orientation, and the yaw angle in particular, is still a challenge and subject of great concern among researchers. This paper presents the development of a platform for yaw angle estimation by fusing inertial and magnetic sensing (a low-cost multi-sensorial system composed by both a digital compass and a gyroscope). A Kalman filter is used to estimate the error produced by the gyroscope. Experimental results indicate that the proposed solution is able to eliminate the drift effect produced by gyroscope data and, at the same time, has the capacity to react to fast orientation changes.
Increasingly, robot programs are generated off-line, for example, through a virtual model of a ro... more Increasingly, robot programs are generated off-line, for example, through a virtual model of a robotic cell. However, when the virtual model does not reproduce exactly the real scenario or the calibration process is not performed correctly it is difficult to generate reliable robot ...
Communications in Computer and Information Science, 2010
Increasingly, robot programs are generated off-line, for example, through a virtual model of a ro... more Increasingly, robot programs are generated off-line, for example, through a virtual model of a robotic cell. However, when the virtual model does not reproduce exactly the real scenario or the calibration process is not performed correctly it is difficult to generate reliable robot ...
Automobile laser brazing remains a complex process whose results are affected by several process ... more Automobile laser brazing remains a complex process whose results are affected by several process variables that may result in nonacceptable welds. A multisensory customized inspection system is proposed, with two distinct non-destructive techniques: the potential drop method and eddy current testing. New probes were designed, simulated, produced, and experimentally validated in automobile’s laser-brazed weld beads with artificially introduced defects. The numerical simulations allowed the development of a new four-point probe configuration in a non-conventional orthogonal shape demonstrating a superior performance in both simulation and experimental validation. The dedicated inspection system allowed the detection of porosities, cracks, and lack of bonding defects, demonstrating the redundancy and complementarity these two techniques provide.
The International Journal of Advanced Manufacturing Technology, 2021
An innovative pilot installation and eddy current testing (ECT) inspection system for laser-braze... more An innovative pilot installation and eddy current testing (ECT) inspection system for laser-brazed joints is presented. The proposed system detects both surface and sub-surface welding defects operating autonomously and integrated with a robotized arm. Customized eddy current probes were designed and experimentally validated detecting pore defects with 0.13 mm diameter and sub-surface defects buried 1 mm deep. The integration of the system and the manufacturing process towards an Industry 4.0 quality control paradigm is also discussed.
IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society, 2019
In this paper we present a novel strategy and implementation of autonomous navigation for the Pep... more In this paper we present a novel strategy and implementation of autonomous navigation for the Pepper robot. The proposed solution is modular and relies on the proper integration of existing Pepper functionalities. The human interacts with the robot using voice and/or gesture commands to setup the robot functionalities. An example use case demonstrates the ability of the robot to navigate in office environment and grasp an object to place in a target location. The robot is also able to avoid obstacles while navigating.
Tese de doutoramento em Engenharia Mecânica, na especialidade de Controlo e Gestao, apresentada a... more Tese de doutoramento em Engenharia Mecânica, na especialidade de Controlo e Gestao, apresentada ao Departamento de Engenharia Mecânica da Faculdade de Ciencias e Tecnologia da Universidade de Coimbra
IECON 2019 - 45th Annual Conference of the IEEE Industrial Electronics Society, 2019
The use of gestures as interface between humans and robots to facilitate communication between th... more The use of gestures as interface between humans and robots to facilitate communication between them is a long-sought goal. Although many gesture solutions have been presented, none of them cope entirely with wrong gesture recognition. This study proposes a novel electromyography (EMG) prototype sensor to capture gestures and also algorithms and procedures to discriminate data containing valid gestures (segmentation). Gestures are recognized using convolutional neural network (CNN) model. The proposed solution presented high recognition accuracy overcoming other similar studies in literature. Test results demonstrated that the proposed solution presents high performance and suggested its use in industrial environment.
Orientation estimation plays a crucial role in robotics. Precise and reliable estimation of orien... more Orientation estimation plays a crucial role in robotics. Precise and reliable estimation of orientation, and the yaw angle in particular, is still a challenge and subject of great concern among researchers. This paper presents the development of a platform for yaw angle estimation by fusing inertial and magnetic sensing (a low-cost multi-sensorial system composed by both a digital compass and a gyroscope). A Kalman filter is used to estimate the error produced by the gyroscope. Experimental results indicate that the proposed solution is able to eliminate the drift effect produced by gyroscope data and, at the same time, has the capacity to react to fast orientation changes.
Increasingly, robot programs are generated off-line, for example, through a virtual model of a ro... more Increasingly, robot programs are generated off-line, for example, through a virtual model of a robotic cell. However, when the virtual model does not reproduce exactly the real scenario or the calibration process is not performed correctly it is difficult to generate reliable robot ...
Communications in Computer and Information Science, 2010
Increasingly, robot programs are generated off-line, for example, through a virtual model of a ro... more Increasingly, robot programs are generated off-line, for example, through a virtual model of a robotic cell. However, when the virtual model does not reproduce exactly the real scenario or the calibration process is not performed correctly it is difficult to generate reliable robot ...
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