Richard Curran

A critical review of Knowledge-Based Engineering: An identification of research challenges

Knowledge-Based Engineering (KBE) is a research field that studies methodologies and technologies for capture and re-use of product and process engineering knowledge. The objective of KBE is to reduce time and cost of product development, which is primarily achieved through automation of repetitive design tasks while capturing, retaining and re-using design knowledge. Published research on KBE is not very extensive and also quite dispersed; this paper is an effort to collect and review existing literature on KBE. A total of 50 research contributions have been analysed. The main objectives of this analysis are to identify the theoretical foundations of KBE and to identify research issues within KBE, pointing out the challenges and pitfalls that currently prohibit a wider adoption of KBE while suggesting avenues for further research. Key findings include (a) the necessity for improved methodological support and adherence, (b) better transparency and traceability of knowledge, (c) the necessity for a quantitative framework to assess the viability and success of KBE development and implementation projects, and (d) the opportunity to move towards mass customization approaches through distributed deployment of KBE in the extended enterprise.

A multidisciplinary implementation methodology for knowledge based engineering: KNOMAD

Existing knowledge-based engineering methodologies offer opportunities for improvement, as the multidisciplinary character of engineering design is not well implemented and as the current methodologies are not optimally substantiated. To better address the integration of multidisciplinary engineering knowledge within a knowledge based engineering (KBE) framework, the KNOMAD methodology has been devised. KNOMAD stands for Knowledge Nurture for Optimal Multidisciplinary Analysis and Design and is a methodology for the analytical utilization, development and evolution of multi-disciplinary engineering knowledge within the design and production realms. The KNOMAD acronym can also be used to highlight KNOMADs formalized process of: (K)nowledge capture; (N)ormalisation; (O)rganisation; (M)odeling; (A)nalysis; and (D)elivery. These implementation steps are taken and repeated as part of the knowledge life cycle and in this context KNOMAD nurtures the whole Knowledge Management across that life cycle. The main contribution of the paper is to highlight the development of the KNOMAD methodology and to substantiate its individual steps with sufficient detail to support the application of KNOMAD in practice. A discipline-specific case study shows the potential of the KNOMAD methodology.

Agent-based modeling and simulation of emergent behavior in air transportation

PurposeCommercial aviation is feasible thanks to the complex socio-technical air transportation system, which involves interactions between human operators, technical systems, and procedures. In view of the expected growth in commercial aviation, significant changes in this socio-technical system are in development both in the USA and Europe. Such a complex socio-technical system may generate various types of emergent behavior, which may range from simple emergence, through weak emergence, up to strong emergence. The purpose of this paper is to demonstrate that agent-based modeling and simulation allows identifying changed and novel rare emergent behavior in this complex socio-technical system.MethodsAn agent based model of a specific operation at an airport has been developed. The specific operation considered is the controlled crossing by a taxiing aircraft of a runway that is in use for controlled departures. The agent-based model includes all relevant human and technical agents, such as the aircraft, the pilots, the controllers and the decision support systems involved. This agent-based model is used to conduct rare event Monte Carlo (MC) simulations.ResultsThe MC simulation results obtained confirm that agent based modeling and simulation of a socio-technical air transportation system allows to identify rare emergent behavior that was not identified through earlier, non-agent-based simulations, including human-in-the-loop simulations of the same operation. A typical example of such emergent behavior is the finding that alerting systems do not really reduce the safety risk.ConclusionsAgent based MC simulations of commercial aviation operations has been demonstrated as a viable way to be evaluated regarding rare emergent behaviour. This rare emergent behaviour could not have been found through the more traditional simulation approaches.

A framework for management of Knowledge-Based Engineering applications as software services: Enabling personalization and codification

Literature on Knowledge-Based Engineering (KBE) has identified challenges concerning the personalization and codification of knowledge for new product development, such as maintaining the quality, accessibility and traceability of knowledge for inspection, review and re-use, as well as managing the life-cycle of KBE applications and the knowledge contained within these applications. This paper reports on the development of a framework that realizes the management of Knowledge-Based Engineering (KBE) applications as software services, and in doing so supports the codification and personalization of knowledge that is used in performing knowledge-intensive product development tasks. The developed framework supports the elicitation and structuring of design and manufacturing knowledge, provides the capacity to run KBE applications as remote software services, and facilitates the distribution and lifecycle management of KBE applications and the underlying knowledge. A learning by doing approach is supported where knowledge can both be personalized and codified as design progresses and new insights are gained. The framework has been successfully applied in an industrial use case that considers the conceptual design of composite aircraft wing covers.

Knowledge-Based Engineering Review: Conceptual Foundations and Research Issues

Knowledge-Based Engineering (KBE) is a developing research field that studies technologies for capture and re-use product and process engineering knowledge to reduce time and cost of product development. KBE has held great promise since its inception, but evolution in the technologies and notions underlying KBE as well as significant challenges towards adoption have so far precluded its main-stream use. The main objective of this paper is to focus on research issues within KBE, pointing out the challenges and pitfalls that currently prohibit a wider adoption of KBE while suggesting possible solutions and avenues for further research. In particular, the case-based ad hoc development of KBE and the ‘black-box’ nature of many KBE applications, subsequent difficulties with knowledge re-use, and insufficient quantification of the benefits of KBE are significant challenges towards a wider adoption of KBE. Methodological and technological advances address some of these issues, and propositions are made to further both qualitative and quantitative analysis and evaluation of KBE applications.

An improved MOEA/D algorithm for bi-objective optimization problems with complex Pareto fronts and its application to structural optimization

The multi-objective evolutionary algorithm based on decomposition (MOEA/D) has been recognized as a promising method for solving multi-objective optimization problems (MOPs), receiving a lot of attention from researchers in recent years. However, its performance in handling MOPs with complicated Pareto fronts (PFs) is still limited, especially for real-world applications whose PFs are often complex featuring, e.g., a long tail or a sharp peak. To deal with this problem, an improved MOEA/D (named iMOEA/D) that mainly focuses on bi-objective optimization problems (BOPs) is therefore proposed in this paper. To demonstrate the capabilities of iMOEA/D, it is applied to design optimization problems of truss structures. In iMOEA/D, the set of the weight vectors defined in MOEA/D is numbered and divided into two subsets: one set with odd-weight vectors and the other with even-weight vectors. Then, a two-phase search strategy based on the MOEA/D framework is proposed to optimize their corresponding populations. Furthermore, in order to enhance the total performance of iMOEA/D, some recent developments for MOEA/D, including an adaptive replacement strategy and a stopping criterion, are also incorporated. The reliability, efficiency and applicability of iMOEA/D are investigated through seven existing benchmark test functions with complex PFs and three optimal design problems of truss structures. The obtained results reveal that iMOEA/D generally outperforms MOEA/D and NSGA-II in both benchmark test functions and real-world applications.

Knowledge-based cost modelling of composite wing structures

The progressive industrialisation of composite-built aircraft is putting manufacturing engineers on a steep learning curve. An opportunity exists to use knowledge management tools to capture, share and reuse knowledge over multiple aircraft programs and maintain the constant flow of learning gained during aircraft program delivery. This article reports on research to develop a knowledge-based cost modelling capability for composite part concept evaluation. The approach integrates a knowledge management environment with a process-based cost estimation tool encoded in very large spreadsheets. To achieve this, the complexity of the cost model is managed by modularising it into simple, re-useable components. The knowledge management environment is then used to manage the knowledge life cycle, knowledge exploitation and knowledge visibility of those components. The result is a flexible cost modelling tool composed of traceable, verifiable and reliable knowledge elements that provides through-life knowledge support for cost engineering. Validation is achieved through functional application of the solution for composite wing top cover cost modelling.

Ontological Modelling of the Aerospace Composite Manufacturing Domain

This paper focuses on the development of an ontology for the aerospace composite manufacturing domain. It uses an amalgam of ontology development methodologies to arrive at a semi-formally declared ontology, which is tested for practical validity in a case study focusing on the construction of an architecture for a knowledge-based engineering solution for an aerospace Original Equipment Manufacturer (OEM).

Concurrent Engineering and Integrated Aircraft Design

With the increasing size and complexity of development projects at large companies and organizations in the aviation industry, concurrent engineering (CE) and integrated aircraft design has become of crucial importance in the design process of new products. In order to remain a competitive position and achieve a customer driven approach, aspects of the product’s life cycle should be adopted at an early stage in the design process. These aspects include, among others: the overall cost performance and the ability of new system integration. This chapter discusses the implementation of CE in the life cycle of aircraft and systems in general. Challenges related to process parallelization and multidisciplinary design, involving the exchange of knowledge and information throughout the design process, are covered. Supporting techniques along with practical case studies are presented to illustrate the implementation of CE and IAD in real life. Expected future developments with respect to CE as applied to aviation conclude this chapter.

DEVELOPMENT OF A SAFETY ASSESSMENT METHODOLOGY FOR THE RISK OF COLLISION OF AN UNMANNED AIRCRAFT SYSTEM WITH THE GROUND

aircraft, UAS performance characteristics are examined. This helps to clarify in which airspace classes the different available UAS may be able to fly. This concerns the broad range of size, various configurations and different performance characteristics. Next, causal models are developed for 15 accident scenario that may result in a collision with the ground. These causal models are represented as Event Sequence Diagrams (ESDs) and Fault Trees (FTs), and provide a logical structure showing how hazards and causal factors could combine to cause a collision with the ground. This approach utilizes the Causal model for Air Transport Safety (CATS) developed for the Dutch Ministry of Transport. Five specific UAS related ESDs are added to cover UAS specific hazards that do not exist in manned aircraft operation. Using the twenty ESDs, a UAS accident probability model for the risk of collision with the ground is developed.