Virtual bloXing - assembly rapid prototyping for near net shapes

Virtual reality (VR) provides another dimension to many engineering applications. Its immersive and interactive nature allows an intuitive approach to study both cognitive activities and performance evaluation. Market competitiveness means having products meet form, fit and function quickly. Rapid Prototyping and Manufacturing (RP&M) technologies are increasingly being applied to produce functional prototypes and the direct manufacturing of small components. Despite its flexibility, these systems have common drawbacks such as slow build rates, a limited number of build axes (typically one) and the need for post processing. This paper presents a Virtual Assembly Rapid Prototyping (VARP) project which involves evaluating cognitive activities in assembly tasks based on the adoption of immersive virtual reality along with a novel nonlayered rapid prototyping for near net shape (NNS) manufacturing of components. It is envisaged that this integrated project will facilitate a better understanding of design for manufacture and assembly by utilising equivalent scale digital and physical prototyping in one rapid prototyping system. The state of the art of the VARP project is also presented in this paper

The influence of immersion and presence in early stage engineering designing and building

This paper explores the role of a designer's sense of engagement in early stage design. In the field of virtual reality, presence and immersion are standard measures of an individual's sense of engagement and involvement in an activity. High levels of presence might indicate that the designer is highly focused on the work. The central research question is the following: do designers who are more engaged in design activity, as measured by presence and immersive tendency questionnaires, produce better designs? An experiment was conducted to assess presence and immersive tendencies within the context of a hands-on, open-ended design-and-build activity. The results indicated that the designers' sense of immersion and presence ranged widely as well as their sense of frustration and calmness while performing the design activity. It was found that higher levels of presence correlated with either high design performance or low design performance. Lower levels of presence correlated with average design performance. No correlations were found between immersive tendency and design performance. This study suggests that some level of presence can be linked with better design, and it implies that level of presence might serve as an indicator of performance and learning in similar design-and-build activities.National Science Foundation (U.S.) (Award CMMI-1130791

Aggregate assembly process planning for concurrent engineering

In today's consumer and economic climate, manufacturers are finding it increasingly difficult to produce finished products with increased functionality whilst fulfilling the aesthetic requirements of the consumer. To remain competitive, manufacturers must always look for ways to meet the faster, better, and cheaper mantra of today's economy. The ability for any industry to mirror the ideal world, where the design, manufacturing, and assembly process of a product would be perfected before it is put mto production, will undoubtedly save a great deal of time and money. This thesis introduces the concept of aggregate assembly process planning for the conceptual stages of design, with the aim of providing the methodology behind such an environment. The methodology is based on an aggregate product model and a connectivity model. Together, they encompass all the requirements needed to fully describe a product in terms of its assembly processes, providing a suitable means for generating assembly sequences. Two general-purpose heuristics methods namely, simulated annealing and genetic algorithms are used for the optimisation of assembly sequences generated, and the loading of the optimal assembly sequences on to workstations, generating an optimal assembly process plan for any given product. The main novelty of this work is in the mapping of the optimisation methods to the issue of assembly sequence generation and line balancing. This includes the formulation of the objective functions for optimismg assembly sequences and resource loading. Also novel to this work is the derivation of standard part assembly methodologies, used to establish and estimate functional tunes for standard assembly operations. The method is demonstrated using CAPABLEAssembly; a suite of interlinked modules that generates a pool of optimised assembly process plans using the concepts above. A total of nine industrial products have been modelled, four of which are the conceptual product models. The process plans generated to date have been tested on industrial assembly lines and in some cases yield an increase in the production rate

APPLICATION OF AUGMENTED REALITY IN MANUAL ASSEMBLY DESIGN AND PLANNING

Ph.DDOCTOR OF PHILOSOPH