James M. Ritchie

Immersive Virtual Reality In Cable and Pipe Routing: Design Metaphors and Cognitive Ergonomics

In recent years there have been moves in industrial engineering towards greater automation through intelligent systems and this has resulted in replacing human expertise. In many cases the potential of intelligent systems has yet to be realised. This paper presents and discusses an alternative technological approach, which uses immersive virtual reality (VR) to support engineering design tasks. The approach focuses on the human engineer and acknowledges the importance of human input to the design process. The development of a metaphor based VR system is reported along with initial field trials, which compare VR with conventional CAD systems. The results show advantages of using VR over CAD and these are discussed along with strengths, weaknesses and future work. @DOI: 10.1115/1.1759696#

The role of non-intrusive operator logging to support the analysis and generation of product engineering data using immersive VR

Virtual reality (VR) has the potential to substantially alter the manner in which products of the future are engineered. Currently there are many applications of VR during the product engineering process from design and analysis through to process planning, assembly, machining and shop floor layout. VR takes a multitude of forms, including immersive, desktop, augmented, and is rapidly developing as a tool that can be used in the engineering of products. This paper looks at the use of immersive VR as a tool for analysing both design and manufacturing product engineering activities in a series of research projects involving assembly planning and cable harness design. It focuses particularly on the use of the non-intrusive logging of users in such environments as a means to obtaining a rich data source for activity analysis and its potential within computer integrated manufacturing environments as a means of providing downstream engineering data.

The Analysis of Design and Manufacturing Tasks Using Haptic and Immersive VR - Some Case Studies'

The use of virtual reality in interactive design and manufacture has been researched extensively but the practical application of this technology in industry is still very much in its infancy. This is surprising as one would have expected that, after some 30 years of research commercial applications of interactive design or manufacturing planning and analysis would be widespread throughout the product design domain. One of the major but less well known advantages of VR technology is that logging the user gives a great deal of rich data which can be used to automatically generate designs or manufacturing instructions, analyse design and manufacturing tasks, map engineering processes and, tentatively, acquire expert knowledge. The authors feel that the benefits of VR in these areas have not been fully disseminated to the wider industrial community and - with the advent of cheaper PC-based VR solutions - perhaps a wider appreciation of the capabilities of this type of technology may encourage companies to adopt VR solutions for some of their product design processes. With this in mind, this paper will describe in detail applications of haptics in assembly demonstrating how user task logging can lead to the analysis of design and manufacturing tasks at a level of detail not previously possible as well as giving usable engineering outputs. The haptic 3D VR study involves the use of a Phantom and 3D system to analyse and compare this technology against real-world user performance. This work demonstrates that the detailed logging of tasks in a virtual environment gives considerable potential for understanding how virtual tasks can be mapped onto their real world equivalent as well as showing how haptic process plans can be generated in a similar manner to the conduit design and assembly planning HMD VR tool reported in PART A. The paper concludes with a view as to how the authors feel that the use of VR systems in product design and manufacturing should evolve in order to enable the industrial adoption of this technology in the future.

The use of non-intrusive user logging to capture engineering rationale, knowledge and intent during the product life cycle

Within the context of life cycle engineering it is important that structured engineering information and knowledge are captured at all phases of the product life cycle for future reference. This is especially the case for long life cycle projects which see a large number of engineering decisions made at the early to mid-stages of a productpsilas life cycle that are needed to inform engineering decisions later on in the process. A key aspect of technology management will be the capturing of knowledge throughout the product life cycle. Numerous attempts have been made to apply knowledge capture techniques to formalise engineering decision rationale and processes; however, these tend to be associated with substantial overheads on the engineer and the company through cognitive process interruptions and additional costs/time. Indeed, when life cycle deadlines come closer these capturing techniques are abandoned due the need to produce a final solution. This paper describes work carried out for non-intrusively capturing and formalising product life cycle knowledge by demonstrating the automated capture of engineering processes/rationale using user logging via an immersive virtual reality system for cable harness design and assembly planning. Associated post-experimental analyses are described which demonstrate the formalisation of structured design processes and decision representations in the form of IDEF diagrams and structured engineering change information. Potential future research directions involving more thorough logging of users are also outlined.

ANALYSIS OF USER ACTIVITY IN AN ENGINEERING DESIGN TASK DURING THE EVALUATION OF AN IMMERSIVE STEREOSCOPIC DESIGN SYSTEM

This paper describes the analysis of user activity during the evaluation of Co-Star, a demonstration immersive stereoscopic design system for cable harness design. During the study ten participants independently completed a sequence of three harness design tasks using the test system. All user interaction was recorded during each of the sessions and subsequently analysed to profile the distribution of user activity into five major activity classes: Design, System Operation, Navigation and Information, and Process Integration. The Design class was further sub-divided into Goal, Support, and Edit activities to produce a more detailed breakdown of this core activity. In addition measures of ‘unproductive activity’ and ‘sequence breaks’ (idle time) were used to identify relative performance within the different activities. The results clearly show the distribution of user activity for this task based on time and number of sequences of user activity and provide a compelling visualisation of this profile, with Navigation typically accounting for 41% and System Operation 23% of user activity whilst Design achieved 27%, in addition it was found that 7% of all activity was found to be unproductive, and 28% of system time was idle. Opportunities to improve operational design performance through targeted system developments can be clearly identified from these results.Copyright

Automatic Decomposition and Refinement of Oversized Components for Rapid Prototyping

The objective of the work presented in this paper is to enable production of large, complex components on rapid prototyping (RP) machines whose build volume is less than the size of the desired component. Such oversized parts can be produced as fabrications if a suitable subdivision can be generated. The methodology presented here creates a decomposition designed for both Rapid Prototyping (DFRP) and assembly (DFA). Any component can be subdivided by an array of orthogonal planes but the shapes resulting from such a brute force approach could have geometries that are difficult to produce accurately on many rapid prototyping systems. Typically, complications will arise when features have insufficient strength to withstand finishing processes or have a cross-section prone to distortion (e.g. warping) during the build process (e.g. thin sections and cusps). Consequently, the method proposed for partitioning considers potential manufacturing problems and modifies the boundaries of individual components where necessary. As part of the decomposition process, the system also generates complimentary male/female (i.e. matching protrusion/depression) assembly features at the interface between the component parts in order to improve the integrity of the final component.Copyright

Virtual Environments — the Eco-Friendly Approach to Product Design?

The use of virtual environments and rapid prototyping in product engineering is expanding rapidly, with research now being carried out over a wide range of product areas. This paper will focus on some of the virtual technologies and applications that have been applied and are currently being used in both research laboratories and industry. It will also highlight the key issues that the author believes should be researched to enable the effective design of environmentally-friendly products.

Automated Design Analysis, Assembly Planning and Motion Study Analysis Using Immersive Virtual Reality

Previous research work at Heriot-Watt University using immersive virtual reality (VR) for cable harness design showed that VR provided substantial productivity gains over traditional computer-aided design (CAD) systems. This follow-on work was aimed at understanding the degree to which aspects of this technology were contributed to these benefits and to determine if engineering design and planning processes could be analysed in detail by nonintrusively monitoring and logging engineering tasks. This involved using a CAD-equivalent VR system for cable harness routing design, harness assembly and installation planning that can be functionally evaluated using a set of creative design-tasks to measure the system and users performance. A novel design task categorisation scheme was created and formalised which broke down the cable harness design process and associated activities. The system was also used to demonstrate the automatic generation of usable bulkhead connector, cable harness assembly and cable harness installation plans from non-intrusive user logging. Finally, the data generated from the user-logging allowed the automated activity categorisation of the user actions, automated generation of process flow diagrams and chronocyclegraphs.

THE ROLE OF CMM AS A TOOL FOR DETECTING, MEASURING AND EVALUATING PERFORMANCE CHANGE IN THE MECHANICAL DESIGN PROCESS

This paper reports on follow-up assessments carried out at industrial sites that had been previously benchmarked using a derivation of the Carnegie- Mellon/SEI Systems Engineering Capability Maturity Model® (SE-CMM® ) called the Process Capability Model — Mechanical Design (PCM-MD). Two sites that had been previously assessed were revisited to carry out another assessment of the mechanical design process in use. The results were initially surprising in that it had been expected that key findings from the first batch of assessments would have been implemented as management had indicated when previous assessment results were released. It was found however that due to significant reorganizations at Group and Company levels that the impetus to improve at site level had not occurred to the degree expected. This showed up as stagnation and in some cases a retrograde movement in many of the capability levels measured. The continued development of the assessment method to include assessing people from key functions that interface closely with mechanical engineers has highlighted the communication issues that can arise across interfaces..