Flavio José Lorini

Comparative analysis between efficiency grouping and efficacy grouping in cell formation using the firefly metaheuristic algorithm

Industrial environments can use several layout setups according to their convenience based on item diversity, ways of production and market demand. This work focuses on design of manufacturing cell formation. A well-known type of production layout in industrial engineering that allows meeting a diversity of production requirements and operational flexibility is the cellular manufacturing. Among the various techniques and approaches applied to manufacturing cell formation, this article uses the firefly metaheuristic algorithm as an optimization engine. Such modern stochastic optimization algorithm can tackle non-convex, non-smooth, non-continuous and non-differentiate objective cost functions making them gradient independent and suitable to manage such problems. The adopted methodology relies on comparing the obtained efficiency and efficacy (clustering) parameters in the cell formation layout with several well-established benchmark examples found in the literature. The results show that the use of efficacy parameter is desirable if the focus relies on clustering manufacturing cell formation, however, the use of efficiency parameter can also lead to useful and cost-effective layouts at the expense of cell clustering. Some of the results also indicate improvements in the efficacy parameter relative to the benchmarked examples with a slightly enhanced layout formation that proves and justifies the suitability for the firefly metaheuristic algorithm.

Comparative Analysis on Wiper and Standard Tools in Dry Finish Turning of Martensitic Stainless Steel AISI 420

Machining performance consists to associate the optimal process and cutting parameters and maximum material removal rate with the most appropriate tool while controlling the machined surface state. This work verifies the influence of standard and wiper cutting tools on generated surface roughness and residual stress in dry finish turning operation of the martensitic stainless steel AISI 420 in a comparative way. Tests are conducted for different combinations of tool nose geometry, feed rate and depth of cut being analyzed through the Design of Experiments regarding to surface roughness parameters Ra and Rt. Moreover, the formation of residual stresses in the material (using the technique of X-Ray Diffraction) was evaluated after the machining process for these two cutting geometries and thereafter the result was compared between them. An ANOVA is performed to clarify the influence of cutting parameters on generated surface roughness, which outputs inform that cutting tool geometry is the most influent on Ra and Rt. It is concluded that analyzed wiper inserts present low performance for low feed rates. Regarding the analysis of the residual stresses it can be stated that for standard and wiper tools the values collected show that for finish turning the compression stresses were found. It can be observed that the greatest amount of compressive stress has been found for the standard tool.

A systematic approach to trajectory planning applied to modular robots

A flexible manufacturing system is defined as a system that has the ability to respond to expected or unexpected changes in a manufacturing process. Currently, one of the options to implement a flexible manufacturing system, is the use of advanced technologies to provide more flexibility, lower cost and reusability. In this context, the modular robots (based in mechatronic modules) can be an alternative to classic manipulators, because they have a variable kinematic structure and are adaptable to changing production lines, being economic for industrial implementations. In this study, taking into account the flexibility characteristics of modular robots, a systematic approach to path planning applied in different modular robotic configurations is presented. The proposed methodology is described as follows: 1) definition of the concepts of a mechatronic module, 2) application of mechatronic modules in assembling of modular robots; and finally, 3) presentation of a system for the path planning of different modular configurations. The studies show that the concepts related to the trajectory planning are important aspects to be considered in self-configurable and flexible platforms.

Architecture Information Context in a Design For Manufacturing (DFM) Framework

This paper presents an analysis of the DFM information demands/requirements and how they could be handled in a framework of this domain. The latest trends as well as both theoretical and technological research advances pose challenges used in the representation of information used by the framework components of this domain. Currently, the main approaches vary from a simple format to an information architecture such as STEP or runtime representation. These aspects, while useful in many cases, are only and mostly focused on data. This limits their flexibility, which is one of the main reasons to use frameworks, especially computer-based ones. Instead, this work proposes the use of a more complete information handling approach based on ontologies. The ontology-based information architecture and its usage in a DFM framework is introduced. Its completeness and usage are important, relevant and complete so it shall be increased in the future when the relatively simple traditional information format becomes obsolete. Along with information architecture and its implementation, the chosen prototype DFM components and architectural aspects requirements are outlined.