Application feature model for geometrical specification of assemblies

The work begins with the description of a Domain Meta-Model for collaborative and integrated product development based on a Feature Model that aggregates all Application Features required to support domain specific reasoning. These Application Features are conceived as an aggregation of several Object Features containing all the knowledge about the structure and geometric interface that are the solution for a certain function. Afterwards, the Specification Feature, as a specialisation of the previous feature, is presented. This contains information about geometry, nominal and with defects, as well as about the relations established between them in the dimensional and geometrical specification process of an assembly, as established by GPS standard. Finally, the Specification Assembly Model is shown, an assembly model based on the Specification Feature and on the description of specifications using the Geospelling language

Ontological model centered on resource capabilities for the inspection process planning

[EN] Planning of a manufacturing process is a knowledge-intensive task in which a lot of information/knowledge must be managed, especially to the most conceptual levels. One of these tasks that is realized at supervisor planning level, consists of the assignment and configuration of resources for each activity to execute. Decisions that must be based on the resource capabilities, which depend largely on resource configuration, so that they can ensure a good result. As it is well known, the ontological approaches have shown well positioned in these cases where knowledge management is needed, moreover, these approaches enable a shared conceptualization, which make it possible to implement process planning in a collaborative environment, particularly when they are accompanied by a methodology that facilitates their interpretation and use. In previous researches, a general ontology for modelling the resource capabilities involved in a process has been proposed. This ontology has been specialized in order to support the process planning task and a methodology supported on graphical representation for validating the configurations of resources assigned in a manufacturing process has been proposed. Based on these results, in this paper, an extended ontology for the inspection process planning is presented. This extension includes new types of activities (inspection activities) and new type of resources (inspection resources), and is centered on the dimensional and geometrical capabilities of the resources. Additionally, using the ontology semantics and the proposed methodology, an application for an inspection plan is developed. The inspection process planning case is focused on the preparation activities used for obtaining the configurations of the resources, since they largely determine the capabilities of the resulting resources. The application demonstrates the proficiency of the ontology to execute manufacturing planning and inspection planning in a dual form.Solano García, L.; Rosado Castellano, P.; Romero Subirón, F. (2017). Ontological model centered on resource capabilities for the inspection process planning. Journal of Manufacturing Technology Research. 8(3-4):115-133. http://hdl.handle.net/10251/116178S11513383-

Ontological-based validation of selected technological resources in integrated machining and inspection process planning

[EN] Based on previous research carried out to characterise the capacities of the resources involved in the execution of process planning, in this paper a methodology is presented for validating the configurations of resources assigned to the activities of integrated machining and inspection process planning. The methodology utilises concepts from the MIRC ontology and has graphic support that makes it more user-friendly. It also places special emphasis on the preparation activities used in the configurations of the resources and has been conceived as an aid to help in the final steps of the development of the process plan.Solano García, L.; Rosado Castellano, P.; Romero Subirón, F. (2015). Ontological-based validation of selected technological resources in integrated machining and inspection process planning. Procedia Engineering. 132:1096-1103. doi:10.1016/j.proeng.2015.12.601S1096110313

Incorporation of form deviations into the matrix transformation method for tolerance analysis in assemblies

Comunicación presentada a MESIC 2019 8th Manufacturing Engineering Society International Conference (Madrid, 19-21 de Junio de 2019)Mathematical models for tolerance representation are used to assess how the geometrical variation of a specific component feature propagates along the assembly, so that tolerance analysis in assemblies can be carried out using a specific tolerance propagation method. Several methods for tolerance analysis have been proposed in the literature, being some of them implemented in CAD systems. All these methods require modelling the geometrical variations of the component surfaces: parametric models, variational models, DoF models, etc. One of the most commonly used models is the DoF model, which is employed in a number of tolerance analysis methods: Small Displacement Torsor (SDT), Technologically and Topologically Related Surfaces (TTRS), Matrix Transformation, Unified Jacobian–Torsor model. However, none of the DoF-based tolerance analysis methods incorporates the effect of form deviations. Among the non DoF-based methods, there are two that include form tolerances: the Vector Loop or Kinematic method and the Tolerance Map (T-Map) model, although the latter is still under development. In this work, a proposal to incorporate form deviations into the matrix transformation method for tolerance analysis in assemblies is developed using a geometrical variation model based on the DoF model. The proposal is evaluated applying it to a 2D case study with components that only have flat surfaces, but the proposal can be extrapolated to 3D cases

Experimental analysis of end mill axis inclination and its influence on 3D areal surface texture parameters

[EN] The surface quality of machined parts depends highly on the surface texture that reflects the marks of the tool during the cutting process. The traditional theoretical approach indicates that these marks are related to the cutting parameters (e.g. cutting speed, feed, depths of cut), the machining type, the part material, the tool, etc. The influence of these factors has been widely studied by researchers and they have been considered in milling process models proposed to predict the final surface texture. Nevertheless, if an accurate prediction is desired, these milling models must include different geometrical errors influencing the cutting edges path on the part. In this paper, we present the results of a study showing the influence of real mill-axis inclination on 3D surface texture. Therefore, experiments with simple, end mill tool operation, with constant cutting parameters and four different cutting directions (the directions that we labelled as North, South, East, and West) in accordance with the machine coordinate system were performed. Using optical 3D areal surface texture measurement techniques with the Bruker Contour device, we obtained areal surface texture parameters for analysis. Descriptive statistical analysis and one-way ANOVA analysis were performed to detect the factor significances and their influence on 3D areal surface texture parameters. The results from ANOVA and graphical analysis clearly identified tool-axis inclination in the South and West directions. If a relationship between tool-axis inclination and surface texture parameters can be demonstrated, this calculation can be included in the model of 3D surface texture formation. Improving the mathematical model with all possible errors occurring in high speed machining operations helps to obtain more precise texture parameter Sz results for simple end mill operation. The model is suitable for complicated machining operations with ball end mill tools.Logins, A.; Rosado Castellano, P.; Torims, T.; Gutiérrez, SC.; Sergejev, F. (2017). Experimental analysis of end mill axis inclination and its influence on 3D areal surface texture parameters. Proceedings of the Estonian Academy of Sciences. 66(2):194-201. doi:10.3176/proc.2017.2.09S19420166

SYSML4TA: A SysML Profile for Consistent Tolerance Analysis in a Manufacturing System Case Application

Tolerance analysis is a key engineering task that is usually supported by domain-specific analysis models and tools that are generally not connected to the system functionality. The model-based system engineering (MBSE) approach is a potential solution to this limitation, but it has not yet been deeply explored in this type of mechanical analysis, for which some problems need to be explored. One of these issues is the capacity of languages such as SysML to describe solution principles based on active surfaces that participate in functionality and are present for tolerance analysis. Thus, this study explored the possibilities that enable SysML to represent these geometries and their mathematical relationships based on Topologically and Technologically Related Surfaces (TTRS) theory and aligned with Geometric Dimensioning and Tolerancing (GD&T) standards. Additionally, the capacity of SysML to assure the consistency of tolerance analysis models is also explored, due to the limitations identified in analysis languages like Modelica. In this context, this paper presents a SysML profile for tolerance analysis modeling (SysML4TA), containing domain-specific semantics (concepts and constraints) to assure the completeness of the analysis models and consistency between the different models considered in the integrated model of the system. Finally, a case study applied to a manufacturing context is presented to validate the capacity of SysML to solve the identified problems.La herencia reconstruida. Crecimiento agrario y transformaciones del paisaje tras las conquistas de al-Andalus (siglos XII-XV

Multidomain Simulation Model for Analysis of Geometric Variation and Productivity in Multi-Stage Assembly Systems

Nowadays, the new era of industry 4.0 is forcing manufacturers to develop models and methods for managing the geometric variation of a final product in complex manufacturing environments, such as multistage manufacturing systems. The stream of variation model has been successfully applied to manage product geometric variation in these systems, but there is a lack of research studying its application together with the material and order flow in the system. In this work, which is focused on the production quality paradigm in a model-based system engineering context, a digital prototype is proposed to integrate productivity and part quality based on the stream of variation analysis in multistage assembly systems. The prototype was modelled and simulated with OpenModelica tool exploiting the Modelica language capabilities for multidomain simulations and its synergy with SysML. A case study is presented to validate the potential applicability of the approach. The proposed model and the results show a promising potential for future developments aligned with the production quality paradigm

Metodología para el desarrollo de modelos de simulación ejecutables para sistemas de fabricación

In recent years, the adoption of the principles of Model Based Systems Engineering (MBSE) in the context of manufacturing systems has promoted the development of highly complex (hybrid simulations, multi-scale, multi-domain, ...) and high- fidelity simulations, some of them applicable even in real time (prototypes and virtual twins). The high complexity of modern manufacturing systems requires the use of well-founded methodologies to effectively and efficiently guide the definition, transformation and adjustment of the simulation models. However, few proposals address the definition of adequate methodologies for the manufacturing systems simulation. This work presents the methodology for Simulation Systems Modeling (SSM methodology), based on the synergistic use of SysML and Modelica. This methodology has been developed to support the construction of executable and multi-domain simulation models for complex manufacturing systems. In addition, a case study is presented, where this methodology is applied to define executable simulation models of a multi- stage assembly line that integrate geometric quality and productivity aspects. The results of this case study enable to compare different control logics, as well as to demonstrate the validity of the proposed methodology

A Tool Condition Monitoring System Based on Low-Cost Sensors and an IoT Platform for Rapid Deployment

Tool condition monitoring (TCM) systems are key technologies for ensuring machining efficiency. Despite the large number of TCM solutions, these systems have not been implemented in industry, especially in small- and medium-sized enterprises (SMEs), mainly because of the need for invasive sensors, time-consuming deployment solutions and a lack of straightforward, scalable solutions from the laboratory. The implementation of TCM solutions for the new era of the Industry 4.0 is encouraging practitioners to look for systems based on IoT (Internet of Things) platforms with plug and play capabilities, minimum interruption time during setup and minimal experimental tests. In this paper, we propose a TCM system based on low-cost and non-invasive sensors that are plug and play devices, an IoT platform for fast deployment and a mobile app for receiving operator feedback. The system is based on a sensing node by Arduino Uno Wi-Fi that acts as an edge-computing node to extract a similarity index for tool wear classification; a machine learning node based on a BeagleBone Black board that builds the machine learning model using a Python script; and an IoT platform to provide the communication infrastructure and register all data for future analytics. Experimental results on a CNC lathe show that a logistic regression model applied on the machine learning node can provide a low-cost and straightforward solution with an accuracy of 88% in tool wear classification. The complete solution has a cost of EUR 170 and only a few hours are required for deployment. Practitioners in SMEs can find the proposed approach interesting since fast results can be obtained and more complex analysis could be easily incorporated while production continues using the operator’s feedback from the mobile app

Diseño de un Kit Modular para Mejorar el Aprendizaje de los Conceptos de Diseño para Ensamblaje (DFA)

Comunicación presentada al XXVII Congreso Universitario de Innovación Educativa en las Enseñanzas Técnicas (Alcoi, 17-19 Junio, 2019.)Students show significant difficulties when having to acquire and take in certain concepts present in some courses in the field of Manufacturing Engineering. Generally, theoretical concepts taught in class are supported by the use of visuals and graphic material. In addition, application cases are solved in practical sessions to complete the acquisition of related skills. However, it has been proved that a considerable amount of students still misunderstands some concepts and finds their application troublesome. In particular, this is the case of some concepts related to the application of Design for Assembly (DFA). In order to enhance the understanding of the concepts and the acquisition of the required skills for their right application, in this work, the design of several DFA modular kits to be experimentally used by students is proposed. The kits will allow students to practise with various product configurations, each of them including different functional inconsistencies. Product features will be modified by replacing portions of the same component (modular kits) rather than by using a large number of different components with the purpose of simplifying the process and illustrating the idea of modifying a component feature instead of replacing it.Los estudiantes presentan dificultades significativas en la adquisición y asimilación de ciertos conceptos presentes en algunas asignaturas del ámbito de la Ingeniería de Fabricación. Generalmente los conceptos teóricos explicados en clase se complementan con material gráfico. Además, la adquisición de las destrezas relacionadas se completa con la resolución de casos de aplicación en sesiones prácticas. Sin embargo, se ha comprobado que una cantidad considerable de estudiantes sigue mostrando dificultades en la compresión de algunos conceptos y encuentra su aplicación problemática. Este el caso de algunos conceptos relacionados con la aplicación del Diseño para Ensamblaje (Design for Assembly, DFA). Con el fin de mejorar la comprensión de los conceptos y la adquisición de las destrezas necesarias para su correcta aplicación, en este trabajo se propone el diseño de kit modular de DFA para ser usado por los estudiantes de forma experimental. Los kits permiten a los estudiantes practicar con varias configuraciones del producto, cada una de ellas con diferentes anomalías funcionales. Se modificarán algunos rasgos característicos del producto sustituyendo partes de un mismo componente (kits modulares) en lugar de utilizando un elevado número de componentes diferentes con el propósito de simplificar el proceso y de inculcar la idea de modificar un rasgo de un componente en lugar de sustituirlo