Reference ontologies for interoperability across multiple assembly systems

The role of information and communication technologies (ICTs) is crucial for future manufacturing organisations in order to support effective collaboration and information sharing. However, the contemporary ICT-based systems lack the required ability to adequately support interoperability across multiple domain systems. The capability of such ICT-based systems to interoperate is impeded by the semantic conflicts arising from loosely defined meanings and intents of the participating system concepts. The aim of this paper is to investigate the interoperability of assembly systems at multiple levels of concept specialisations using the concept of a formal reference ontology. Formal ontologies are providing a promising way to computationally capture the domain meanings which can subsequently provide a base to support interoperability across multiple systems and in our case multiple assembly systems. This paper takes the example of manufacturing bill of materials concept and three different domain-specific interpretations to explore and demonstrate the potential of formal reference ontologies to support interoperability

Explicitly representing the semantics of composite positional tolerance for patterns of holes

Representing the semantics of the interaction of two or more tolerances (i.e. composite tolerance) explicitly to make them computer-understandable is currently a challenging task in computer-aided tolerancing (CAT). We have proposed a description logic (DL) ontology based approach to complete this task recently. In this paper, the representation of the semantics of the composite positional tolerance (CPT) for patterns of holes (POHs) is used as an example to illustrate the proposed approach. This representation mainly includes: representing the structure knowledge of the CPT for POHs in DL terminological axioms; expressing the constraint knowledge with Horn rules; and describing the individual knowledge using DL assertional axioms. By implementing the representation with the web ontology language (OWL) and the semantic web rule language (SWRL), a CPT ontology is developed. This ontology has explicitly computer-understandable semantics due to the logic-based semantics of OWL and SWRL. As is illustrated by an engineering example, such semantics makes it possible to automatically check the consistency, reason out the new knowledge, and implement the semantic interoperability of CPT information. Benefiting from this, the ontology provides a semantic enrichment model for the CPT information extracted from CAD/CAM systems

Reference ontologies for interoperability across multiple assembly systems

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Production Research on 28 Sep 2015, available online: http://dx.doi.org/10.1080/00207543.2015.1087654The role of information and communication technologies (ICTs) is crucial for future manufacturing organisations in order to support effective collaboration and information sharing. However, the contemporary ICT-based systems lack the required ability to adequately support interoperability across multiple domain systems. The capability of such ICT-based systems to interoperate is impeded by the semantic conflicts arising from loosely defined meanings and intents of the participating system concepts. The aim of this paper is to investigate the interoperability of assembly systems at multiple levels of concept specialisations using the concept of a formal reference ontology. Formal ontologies are providing a promising way to computationally capture the domain meanings which can subsequently provide a base to support interoperability across multiple systems and in our case multiple assembly systems. This paper takes the example of manufacturing bill of materials concept and three different domain-specific interpretations to explore and demonstrate the potential of formal reference ontologies to support interoperability

Gestión de ontologías e instanciación en modelos de fabricación

En la actualidad, las empresas viven en un entorno cada vez más competitivo en el que no es suficiente con ser eficaz, sino que hay que ser eficiente si se quiere permanecer en el mercado. Hoy en día, el hecho de entregar un producto de calidad a tiempo empieza a estar al alcance de cualquiera, si se quiere marcar la diferencia para competir en el mercado se tiene que ser eficiente, es decir, se tiene que hacer optimizando el uso de recursos. Esto no va en relación con el número de recursos en sí, sino con cómo funcionan y si se les saca el máximo rendimiento. No importa cuántos recursos tengas. Si no los sabes usar, nunca serán suficientes. Con el conocimiento sucede lo mismo. No es cuánto tengas, sino cómo lo usas y para qué. Está claro que es necesario adquirir conocimiento, pero de nada vale tener información que no sirve o información que sirve, pero no se sabe interpretar ni transmitir adecuadamente. Históricamente, siempre se ha empleado mucho tiempo en el diseño de nuevos productos y sus procesos de fabricación. Además, cada vez se requieren productos más avanzados y customizados, por lo que el desarrollo se ha vuelto más complicado, pero si se quiere ser competitivo hay que ser eficiente. Hay que introducir los productos en el mercado de manera más rápida, por eso es importante tener una buena base que permita no tener que empezar de cero cada vez que se requiera desarrollar el diseño o la fabricación de un producto. Por este motivo, el hecho de extraer todo tipo de información para nuevos productos se convierte en una necesidad, pero de nada vale tener información si ésta no se almacena, transmite e interpreta correctamente. De esto último trata la interoperabilidad, de compartir conocimiento sin que se pierda información. La interoperabilidad es clave en un sector en el que entra en juego una cadena de suministro. Cuantos más agentes entren a formar parte de la cadena más veces se tiene que compartir la información y mayor es la probabilidad de que ésta no se transmita correctamente. El objetivo de este TFM es desarrollar una herramienta que permita la comunicación entre aplicaciones diferentes y demostrar que es posible transmitir el conocimiento entre ellas a través de ontologías.Universidad de Sevilla. Máster en Ingeniería Aeronáutic

An automated method mapping parametric features between computer aided design software

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University LondonEnterprise efficiency is limited by data exchange. A product designer might specify the geometry of a product with a Computer Aided Design program, an engineer might re-use that geometry data to calculate physical properties of the product using a Finite Element Analysis program. These different domains place different requirements on the product representation. Representations of product data required for different tasks is dependent on the vendor software associated with those tasks, sharing data between different vendor programs is limited by incompatibility of the vendor formats used. In the case of Computer Aided Design where the virtual form of an object is modelled, no standard data format captures complete model data. Common data standards transfer model surface geometry without capturing the topological elements from which these geometries are constructed. There are prescriptive data representations to allow these features to be specified in a neutral format, but little incentive for vendors to adopt these schemes. Recent efforts instead focus on identifying similar feature elements between different vendor CAD programs, however this approach relies on onerous manual identification requiring frequent revision. This research develops methods to automate the task of mapping relationships between different data format representations. Two independent matching techniques identify similar CAD feature functions between heterogeneous programs. Text similarity and object geometry matching techniques are combined to match the data formats associated with CAD programs. An efficient search for matching function parameters is performed using a genetic algorithm that incorporates semantic data matching and geometry data matching. A greedy semantic matching algorithm is developed that compares with the Doc2vec short text matching technique over the API dataset tested. A SVD geometric surface registration technique is developed that requires fewer calculations than an equivalent Iterative Closest Point method