2010
Autores
Mendes, N; Neto, P; Pires, JN; Moreira, AP;
Publicação
TRENDS IN INTELLIGENT ROBOTICS
Abstract
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 programs. In order to circumvent this problem, it was introduced sensory feedback (force and torque sensing) in a robotic framework. By controlling the robot end-effector pose and specifying its relationship to the interaction/contact forces, robot programmers can ensure that the robot maneuvers correctly, damping possible impacts and also increasing the tolerance to positioning errors from the off-line programming process. In this paper Fuzzy-PI and PI reasoning was proposed as a force control technique. The effectiveness of the proposed approach was evaluated in a serie of 20 experiments that demonstrated that Fuzzy-PI controllers are more suitable to deal with this type of situations.
2010
Autores
Neto, P; Mendes, N; Mourato, N; Pires, JN; Moreira, AP;
Publicação
TRENDS IN INTELLIGENT ROBOTICS
Abstract
Today, industrialized countries are facing a major problem, the lack of skilled engineers. Despite the increasing demand for engineers in the labor market, the number of students going to engineering courses has been declining. This paper reports some initiatives carried out by the industrial robotics laboratory of the University of Coimbra (Portugal) which can contribute to help the youths to obtain an enlarged image of what the engineers can do. These initiatives have focused on the organization of one-day visits to the university campus and participation in events (fairs and exhibitions) to disseminate science and technology. Our participation in such initiatives has been done through the exhibition of a robotic platform to be experienced by the public, usually high school students. In order to allow visitors to intuitively drive the robot, two human-robot interfaces (HRI) has been used. So, to make the process more appealing, the visitors will not only drive the robot but also will play a game with the robot. Besides, it is also important for us receive feedback from the visitors. In such way, a questionnaire about their understanding of the presented robotic platform was proposed. Some points regarding the questionnaires are pointed out for discussion, the students' interest in robotics and the effectiveness of our "hands-on' robotic platform. Results are presented by dividing the answers collected by gender.
2011
Autores
do Nascimento, TP; Fontes, FA; Moreira, AP; Conceicao, AGS;
Publicação
ICINCO 2011: PROCEEDINGS OF THE 8TH INTERNATIONAL CONFERENCE ON INFORMATICS IN CONTROL, AUTOMATION AND ROBOTICS, VOL 2
Abstract
This paper describes a novel approach in formation control for mobile robots. Here, a Nonlinear Model Predictive Controller (NMPC) is used to maintain the formation of three omnidirectional mobile robots. The details of the controller structure are presented as well as its functionality in a soccer robot team. Three Middle Size League Robots are used for evaluation. A case of study based in a soccer robot situation is presented, developed, and implemented to evaluate the performance of the controller. Simulations results are presented and discussed.
2011
Autores
do Nascimento, TP; Scolari Conceição, AG; Alves, HP; Fontes, FA; Moreira, AP;
Publicação
RoboCup 2011: Robot Soccer World Cup XV [papers from the 15th Annual RoboCup International Symposium, Istanbul, Turkey, July 2011]
Abstract
This paper describes a novel approach in formation control for mobile robots. A Nonlinear Model Predictive Controller (NMPC) is used to control the formation of a heterogeneous mobile robots group. The desired formation is formed by an holonomic robot and a nonholonomic robot. The same nonlinear controller is used in both robots with the same cost function. The details of the controller structure are presented in order to track a fixed target departing from different positions in the field avoiding collisions with each other. A soccer robot competition field is used to present the simulations to evaluate the performance of the controller. © 2012 Springer-Verlag Berlin Heidelberg.
2012
Autores
Ferreira, M; Moreira, AP; Neto, P;
Publicação
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
Abstract
In this paper, an adaptive and low-cost robotic coating platform for small production series is presented. This new platform presents a flexible architecture that enables fast/automatic system adaptive behaviour without human intervention. The concept is based on contactless technology, using artificial vision and laser scanning to identify and characterize different workpieces travelling on a conveyor. Using laser triangulation, the workpieces are virtually reconstructed through a simplified cloud of three-dimensional (3D) points. From those reconstructed models, several algorithms are implemented to extract information about workpieces profile (pattern recognition), size, boundary and pose. Such information is then used to on-line adjust the "base" robot programmes. These robot programmes are off-line generated from a 3D computer-aided design model of each different workpiece profile. Finally, the robotic manipulator executes the coating process after its "base" programmes have been adjusted. This is a low-cost and fully autonomous system that allows adapting the robot's behaviour to different manufacturing situations. It means that the robot is ready to work over any piece at any time, and thus, small production series can be reduced to as much as a one-object series. No skilled workers and large setup times are needed to operate it. Experimental results showed that this solution proved to be efficient and can be applied not only for spray coating purposes but also for many other industrial processes (automatic manipulation, pick-and-place, inspection, etc.).
2010
Autores
Neto, P; Mendes, N; Pires, JN; Moreira, AP;
Publicação
2010 IEEE International Conference on Automation Science and Engineering
Abstract
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