2018
Authors
Coutinho, CP; Baptista, AJ; Rodriges, JD;
Publication
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
Abstract
Similitude theory is a branch of engineering science concerned with establishing the necessary and sufficient conditions of similarity among phenomena, and has been applied to different fields such as structural engineering, vibration and impact problems. Testing of subscale models is still nowadays a valuable design tool, helping engineers to accurately predict the behavior of oversized prototypes through scaling laws applied to the obtained experimental results. However, several limitations and difficulties still persist when applying the similitude theory through the current methodologies to complex structures. This manuscript presents an original modular approach. The objective is to improve how the similitude theory is applied through the governing equations, overcoming part of the identified constraints. The major achievement is that, with the new approach, the similitude theory can be applied to complex structures through differential equations of its simple substructures, even if the governing equations for the whole structure are not available. A stiffened plate is selected to demonstrate the use of the modular approach and the accuracy of the scaled model testing. To that end, the modular approach has to be firstly applied to the generalized simple plate and beam. Even though the simplifying assumptions are minimized in the substructure governing equations, the modular, approach is able to avoid the expected increase in the mathematical effort and complexity of the process of applying the similitude theory. In a second step, a relation is established between the scaling relationships derived for each simple structural element of the complex prototype.
2017
Authors
Sadeghi, P; Rebelo, RD; Soeiro Ferreira, J;
Publication
IFIP Advances in Information and Communication Technology
Abstract
Portuguese footwear industry has improved dramatically to become one of the main world players. This work is part of a project in cooperation with a large footwear company, operating a new automated assembly equipment, integrating various lines. Balancing such lines implies going from an almost manual preparation executed by experienced operators, to a planning supported by optimisation systems. These complex mixed-model lines have distinctive characteristics, which make balancing a unique problem. The paper proposes the ASBsm – Assembly System Balancing Solution Method, a new method that integrates a constructive heuristic and an improvement heuristic, which takes inspiration from Tabu Search. The solutions obtained, based on real instances, are quite encouraging when compared with other effected factory solutions. Consequently, the balances obtained by ASBsm are now being implemented and articulated with sequencing methods. © IFIP International Federation for Information Processing 2017.
2017
Authors
Arrais, R; Oliveira, M; Toscano, C; Veiga, G;
Publication
JOURNAL OF MANUFACTURING SYSTEMS
Abstract
This paper demonstrates the potential benefits of the integration of robot based sensing and Enterprise Information Systems extended with information about the geometric location and volumetric information of the parts contained in logistic supermarkets. The comparison of this extended world model with hierarchical spatial representations produced by a fleet of robots traversing the logistic supermarket corridors enables the continuous assessment of inconsistencies between reality, i.e., the spatial representations collected from online 3D data, and the modelled information, i.e., the world model. Results show that it is possible to detect inconsistencies reliably and in real time. The proposed approach contributes to the development of more robust and effective Enterprise Information Systems.
2017
Authors
Barros, AC; Simões, AC; Toscano, C; Marques, A; Rodrigues, JC; Azevedo, A;
Publication
Proceedings of International Conference on Computers and Industrial Engineering, CIE
Abstract
Cyber-physical systems (CPS) are a new generation of systems that integrate computation and physical processes interacting with humans in different ways. Integrated networks of computers, sensors and similar technologies monitor and control the physical processes, reporting relevant data to planners and decision-makers, and vice versa. By means of case research, this paper analyzes the implementation of cyber-physical systems aiming at lead-time reduction in two manufacturing contexts, namely footwear and natural cork stoppers. The results of this research contribute to literature and practice with a conceptual framework for the implementation of cyber-physical systems and the discussion of the challenges of implementing this technology.
2017
Authors
Rovida, F; Krueger, V; Nalpantidis, L; Charzoule, A; Lasnier, A; Petrick, R; Crosby, M; Toscano, C; Veiga, G;
Publication
ADVANCES IN COOPERATIVE ROBOTICS
Abstract
Cognitive robots have started to find their way into manufacturing halls. However, the full potential of these robots can only be exploited through an integration into the automation pyramid so that the system is able to communicate with the manufacturing execution system (MES). Integrating the robot with the MES allows the robot to get access to manufacturing environment and process data so that it can perform its task without human intervention. This paper describe the mobile robotic manipulator developed in the EU project STAMINA, its has been integrated with an existing MES and its application in a kitting task from the automotive industry.
2017
Authors
Crosby, M; Petrick, RPA; Toscano, C; Dias, RC; Rovida, F; Krüger, V;
Publication
CEUR Workshop Proceedings
Abstract
This paper presents an integrated cognitive robotics system for industrial kitting operations in a modern factory setting. The robot system combines low-level robot control and execution monitoring with automated mission and task planning, and a logistics planner which communicates with the factory's manufacturing execution system. The system has been implemented and tested on a series of automotive kitting problems, where collections of parts are picked from a warehouse and delivered to the production line. The system has been empirically evaluated and the complete framework shown to be successful at assembling kits in a small factory environment.
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