Manufacturing Algebra. Part II: aggregation, control and simulation

Manufacturing Algebra provides a set of mathematical entities together with some composition rules, that are specially conceived for modelling and controlling a manufacturing system. Here only the modelling capabilities are outlined together with a simple case study. The scope of the paper is to familiarize the reader with the proposed methodology, and to highlight some peculiarities. Formulation is reduced to a minimum. Among the algebra peculiarities, both manufacturing process and the factory layout are defined in their basic elements, and the link between them is given. Specifically the Manufacturing Model (parts, operations) includes time and space coordinates in order it could be employed by factory elements like Production units and Control Units. This calls for the definition of event and event sequence and of the relevant discrete-event elements and operators. A further peculiarity to be clarified in the second part, is the capability of aggregating algebra elements into higher level components, thus favoring hierarchical description and control of manufacturing system

Infrared Thermography for Investigation of Surface Quality in Dry Finish Turning of Ti6Al4V

The machining of titanium alloys always raises issues because of their peculiar chemical and physical characteristics as compared to traditional steel or aluminum alloys. A proper selection of parameters and their monitoring during the cutting operation makes it possible to minimize the surface roughness and cutting force. In this experimental study, infrared thermography was used as a control parameter of the surface roughness of Ti6A4V in dry finish turning. An analysis of variance was carried out to determine the effect of the main cutting parameters (cutting speed and feed rate) on the surface roughness and cutting temperature. In the examined range of the machining parameters, cutting speed and feed were found to have a primary effect on the surface roughness of the machined parts. Cutting speed also significantly affected the temperature of the cutting region, while feed was of second order. Higher cutting speeds and intermediate feed values gave the best surface roughness. A regression analysis defined some models to relate the cutting temperature and surface roughness to the machining parameters. Infrared thermography demonstrated that the cutting temperature could be related to roughness

Discrimination of hidden information in measurement results

In a growing economy, standardization promotes the exchange of products, people and processes but it is during industrial crises that standardization fosters the economic recovery. The Geometrical Product Specification (GPS) Project aims to develop a new, universal, univoque and mathematical based language to express the geometrical variability of manufactured products. The knowledge of GPS standards not only provides a competitive edge to manufacturing enterprises, which design, produce and control products with higher quality, but also increases the competitiveness of a whole industrial district or country promoting the cooperation between enterprises. GPS explores components of uncertainties, from the specification to the verification phase. Even if the GPS project provides a description of variability along the product life cycle, it is significant to discriminate hidden information on measurement results, in order to gain the most quantity of information into the manufacture variability. Methods to discriminate information are analyzed for macro geometry with a partitioning probabilistic method and for profiles with independent component analysis techniques