Supporting connectivism in knowledge based engineering with graph theory, filtering techniques and model quality assurance

[EN] Mass-customization has forced manufacturing companies to put significant efforts to digitize and automate their engineering and production processes. When new products are to be developed and introduced the production is not alone to be automated. The application of knowledge regarding how the product should be designed and produced based on customer requirements also must be automated. One big academic challenge is helping industry to make sure that the background knowledge of the automated engineering processes still can be understood by its stakeholders throughout the product life cycle. The research presented in this paper aims to build an infrastructure to support a connectivistic view on knowledge in knowledge based engineering. Fundamental concepts in connectivism include network formation and contextualization, which are here addressed by using graph theory together with information filtering techniques and quality assurance of CAD-models. The paper shows how engineering knowledge contained in spreadsheets, knowledge-bases and CAD-models can be penetrated and represented as filtered graphs to support a connectivistic working approach. Three software demonstrators developed to extract filtered graphs are presented and discussed in the paper.The work presented has evolved during the IMPACT project, funded by the Swedish Knowledge Foundation, and has been partly presented on three conferences [8-10]. The three conference papers show the rendering of graphs for CAD-models, spread sheets and KBE-rules together with the first case example in this article. The work has also been partially supported by grant DPI2017-84526-R (MINECO/AEI/FEDER, UE), project CAL-MBE.Johansson, J.; Contero, M.; Company, P.; Elgh, F. (2018). Supporting connectivism in knowledge based engineering with graph theory, filtering techniques and model quality assurance. Advanced Engineering Informatics. 38:252-263. https://doi.org/10.1016/j.aei.2018.07.005S2522633

A structured approach to defect data management for improving DFM implementation in aerospace manufacturing

The aim of adopting Product Lifecycle Management in a highly product centric knowledge environment is to reduce product development time and costs whilst improving quality by effectively integrating people, processes, resources and information. In the aerospace industry, most products and systems are manufactured, delivered to customers and serviced over an extensively long time, typically 20 years or more. This results in building up large amounts of dispersed data and information related to defects throughout the product’s lifecycle, hence inhibiting the ability to make effective use of defect data for the purpose of improving design for manufacturing implementation. There have been very limited research efforts aiming to overcome these challenges in the low volume high value aerospace manufacturing context. This paper presents the findings of an extensive industrial investigation carried out at BAE Systems (Rochester, UK) to identify the gaps and requirements in the industrial practice and proposes the need for structured approach to defect data management in order to establish the systematic link between the defects, engineering data, and related issues within PLM System context

Capturing, structuring and accessing design rationale in integrated product design and manufacturing processes

Developing customized products is the business case for many manufacturing companies striving to fulfill the customers’ specific needs. When manufacturing customized products it is often necessary to also develop corresponding customized manufacturing tooling. There is a need to support concurrent development of new product variants along with their manufacturing toolsets. The communication between design engineers and manufacturing engineers is hence a key issue that if solved would enable design engineers to foresee how changes in product design affect tooling design and vice versa. To understand the correlation between the design of a product and its corresponding manufacturing tools, access to design rationale of the product and the developed tooling is required. Design rationale provides an explanation of why an artifact is designed in the way it is, including statements (textual, numerical or geometrical), argumentations, and decisions. Since design rationale is composed of information scattered all across the company's repositories in different formats (e.g. in type of a geometry, picture, table, and textual document), representing the design rationale is a challenge for many enterprises. In this paper a method is introduced that enables capture, structure and access to design rationale across product design and tooling design. The system enables representing design rationale in formats such as CAD models, spreadsheets, textual formats, and web pages. The method has been examined by developing a prototype system tested in a case company which develops and manufactures customized car accessories, such as roof racks and bike carriers, for different car models. The company develops and manufactures the products as well as the required tooling equipment. The prototype system includes different software commonly used by engineers during designing a product, for the purpose of making it applicable for other companies.Included in thesis as submitted manuscript.</p

An integrated system to design machine layouts for modular special purpose machines

This thesis introduces the development of an integrated system for the design of layouts for special purpose machines (SPMs). SPMs are capable of performing several machining operations (such as drilling, milling, and tapping) at the same time. They consist of elements that can be arranged in different layouts. Whilst this is a unique feature that makes SPMs modular, a high level of knowledge and experience is required to rearrange the SPM elements in different configurations, and also to select appropriate SPM elements when product demand changes and new layouts are required. In this research, an integrated system for SPM layout design was developed by considering the following components: an expert system tool, an assembly modelling approach for SPM layouts, an artificial intelligence tool, and a CAD design environment. SolidWorks was used as the 3D CAD environment. VisiRule was used as the expert system tool to make decisions about the selection of SPM elements. An assembly modelling approach was developed with an SPM database using a linked list structure and assembly relationships graph. A case-based reasoning (CBR) approach was developed and applied to automate the selection of SPM layouts. These components were integrated using application programing interface (API) features and Visual Basic programming language. The outcome of the application of the novel approach that was developed in this thesis is reducing the steps for the assembly process of the SPM elements and reducing the time for designing SPM layouts. As a result, only one step is required to assemble any two SPM elements and the time for the selection process of SPM layouts is reduced by approximately 75% compared to the traditional processes. The integrated system developed in this thesis will help engineers in design and manufacturing fields to design SPM layouts in a more time-effective manner

A process model in platform independent and neutral formal representation for design engineering automation

An engineering design process as part of product development (PD) needs to satisfy ever-changing customer demands by striking a balance between time, cost and quality. In order to achieve a faster lead-time, improved quality and reduced PD costs for increased profits, automation methods have been developed with the help of virtual engineering. There are various methods of achieving Design Engineering Automation (DEA) with Computer-Aided (CAx) tools such as CAD/CAE/CAM, Product Lifecycle Management (PLM) and Knowledge Based Engineering (KBE). For example, Computer Aided Design (CAD) tools enable Geometry Automation (GA), PLM systems allow for sharing and exchange of product knowledge throughout the PD lifecycle. Traditional automation methods are specific to individual products and are hard-coded and bound by the proprietary tool format. Also, existing CAx tools and PLM systems offer bespoke islands of automation as compared to KBE. KBE as a design method incorporates complete design intent by including re-usable geometric, non-geometric product knowledge as well as engineering process knowledge for DEA including various processes such as mechanical design, analysis and manufacturing. It has been recognised, through an extensive literature review, that a research gap exists in the form of a generic and structured method of knowledge modelling, both informal and formal modelling, of mechanical design process with manufacturing knowledge (DFM/DFA) as part of model based systems engineering (MBSE) for DEA with a KBE approach. There is a lack of a structured technique for knowledge modelling, which can provide a standardised method to use platform independent and neutral formal standards for DEA with generative modelling for mechanical product design process and DFM with preserved semantics. The neutral formal representation through computer or machine understandable format provides open standard usage. This thesis provides a contribution to knowledge by addressing this gap in two-steps: • In the first step, a coherent process model, GPM-DEA is developed as part of MBSE which can be used for modelling of mechanical design with manufacturing knowledge utilising hybrid approach, based on strengths of existing modelling standards such as IDEF0, UML, SysML and addition of constructs as per author’s Metamodel. The structured process model is highly granular with complex interdependencies such as activities, object, function, rule association and includes the effect of the process model on the product at both component and geometric attributes. • In the second step, a method is provided to map the schema of the process model to equivalent platform independent and neutral formal standards using OWL/SWRL ontology for system development using Protégé tool, enabling machine interpretability with semantic clarity for DEA with generative modelling by building queries and reasoning on set of generic SWRL functions developed by the author. Model development has been performed with the aid of literature analysis and pilot use-cases. Experimental verification with test use-cases has confirmed the reasoning and querying capability on formal axioms in generating accurate results. Some of the other key strengths are that knowledgebase is generic, scalable and extensible, hence provides re-usability and wider design space exploration. The generative modelling capability allows the model to generate activities and objects based on functional requirements of the mechanical design process with DFM/DFA and rules based on logic. With the help of application programming interface, a platform specific DEA system such as a KBE tool or a CAD tool enabling GA and a web page incorporating engineering knowledge for decision support can consume relevant part of the knowledgebase