Automatic generation of robot and manual assembly plans using octrees

This paper aims to investigate automatic assembly planning for robot and manual assembly. The octree decomposition technique is applied to approximate CAD models with an octree representation which are then used to generate robot and manual assembly plans. An assembly planning system able to generate assembly plans was developed to build these prototype models. Octree decomposition is an effective assembly planning tool. Assembly plans can automatically be generated for robot and manual assembly using octree models. Research limitations/implications - One disadvantage of the octree decomposition technique is that it approximates a part model with cubes instead of using the actual model. This limits its use and applications when complex assemblies must be planned, but in the context of prototyping can allow a rough component to be formed which can later be finished by hand. Assembly plans can be generated using octree decomposition, however, new algorithms must be developed to overcome its limitations

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

Octree-based production of near net shape components

Near net shape (NNS) manufacturing refers to the production of products that require a finishing operation of some kind. NNS manufacturing is important because it enables a significant reduction in: machining work, raw material usage, production time, and energy consumption. This paper presents an integrated system for the production of near net shape components based on the Octree decomposition of 3-D models. The Octree representation is used to automatically decompose and approximate the 3-D models, and to generate the robot instructions required to create assemblies of blocks secured by adhesive. Not only is the system capable of producing shapes of variable precision and complexity (including overhanging or reentrant shapes) from a variety of materials, but it also requires no production tooling (e.g., molds, dies, jigs, or fixtures). This paper details how a number of well-known Octree algorithms for subdivision, neighbor findings, and tree traversal have been modified to support this novel application. This paper ends by reporting the construction of two mechanical components in the prototype cell, and discussing the overall feasibility of the system

Quantum optical waveform conversion

Currently proposed architectures for long-distance quantum communication rely on networks of quantum processors connected by optical communications channels [1,2]. The key resource for such networks is the entanglement of matter-based quantum systems with quantum optical fields for information transmission. The optical interaction bandwidth of these material systems is a tiny fraction of that available for optical communication, and the temporal shape of the quantum optical output pulse is often poorly suited for long-distance transmission. Here we demonstrate that nonlinear mixing of a quantum light pulse with a spectrally tailored classical field can compress the quantum pulse by more than a factor of 100 and flexibly reshape its temporal waveform, while preserving all quantum properties, including entanglement. Waveform conversion can be used with heralded arrays of quantum light emitters to enable quantum communication at the full data rate of optical telecommunications.Comment: submitte

Private And Public Sector Ethics

Differences between public and private-sector organizations were proposed to lead to different ethical perceptions, principles and judgments.  As expected, employees working in the public and private sector and enrolled in a night MBA program did display significantly different ethical judgments that appeared to be partially, but not completely explained by significant differences in the ethical principles they reported emphasizing. Ethical decision-making models suggest, as we do, that differing ethical perceptions also played a part in the different judgments found

Business Student And Practitioner Work Goals And Their Implications

The correspondence between individual work goals and available organizational rewards is a primary determinant of job satisfaction and motivation and is also likely to impact job performance. Differences between upper and lower division business students’ work goals suggest that changes had occurred as the students progressed through the curriculum that are likely to be functional for their work adjustment in modern organizations affected by current trends in job and organization design. However, some student priorities remained poorly matched with the available rewards and work requirements they are likely to find in these organizations.  The mismatched priorities contrasted sharply with those displayed by U.S. managers in a previous study

Manager And Business Student Work Goals: Implications And Recommendations For Educators

The correspondence between work goals, work requirements, and available organizational rewards is a primary determinant of job satisfaction and motivation and is also likely to impact job performance. Research suggests managers’ but not business students’ work goal priorities are well matched with the work requirements and available rewards of modern business organizations. Educational implications are discussed and recommendations are made to increase students’ understanding of the importance and impact of work goals in modern organizations and to facilitate their adjustment to the reward conditions and work requirements that they are likely to face in these organizations. The recommended work goal and adjustment module, which is integrated into the topic of motivation, is also expected to increase student understanding and interest in the motivation material by encouraging students to apply it to work adjustment and by helping them more personally relate to the motivation principles applied

Automated knowledge capture in 2D and 3D design environments

In Life Cycle Engineering, it is vital that the engineering knowledge for the product is captured throughout its life cycle in a formal and structured manner. This will allow the information to be referred to in the future by engineers who did not work on the original design but are wanting to understand the reasons that certain design decisions were made. In the past, attempts were made to try to capture this knowledge by having the engineer record the knowledge manually during a design session. However, this is not only time-consuming but is also disruptive to the creative process. Therefore, the research presented in this paper is concerned with capturing design knowledge automatically using a traditional 2D design environment and also an immersive 3D design environment. The design knowledge is captured by continuously and non-intrusively logging the user during a design session and then storing this output in a structured eXtensible Markup Language (XML) format. Next, the XML data is analysed and the design processes that are involved can be visualised by the automatic generation of IDEF0 diagrams. Using this captured knowledge, it forms the basis of an interactive online assistance system to aid future users who are carrying out a similar design task

Does biodiversity restore us? The relationship between public perceptions of amenity and biodiversity in urban river corridors in Melbourne

Most urban river corridors are located within public land which plays a crucial role in supporting threatened urban biodiversity. These spaces are also frequently accessed and valued by the public for the recreational, psychological and restorative values that they possess. As urban density increases, so too, the pressures (such as development, urban heat and stormwater) on urban river corridors and adjacent public land increases. The manner in which these spaces are managed is of great importance if the needs of both biodiversity and humans are to be met. The development of appropriate environmental management strategies requires that we understand the interactions between people and the environments in which they live. Public perceptions studies have traditionally focused on how people perceive nature with particular emphasis on visual perception. However, public perception studies of urban river corridors are generally limited and studies undertaken in-situ are particularly scarce.  Although it is generally agreed that contact with nature has restorative value, identifying which specific elements or qualities of nature are most restorative has received less attention, especially in relation to urban river corridors.  Furthermore, if urban river corridors are going to be managed to benefit both people and biodiversity there is also a need to identify whether biodiversity levels have an influence on the restorative potential of urban river corridors and nature in general.  To address these short-coming, the primary objective of my research is to improve the usefulness of public perceptions of amenity as a component of river corridor and public land management by providing a clearer articulation of how amenity is perceived by the public and how it relates to biodiversity. Understanding the broader social environment is a critical aspect of urban biodiversity projects on public land as the interaction between people and the environment will have implications for project success. Gaining a clearer appreciation of public perceptions of amenity values of urban river corridors has been identified as important for developing beneficial management strategies. Employing an interpretivist qualitative approach, I explore interactions between the social and ecological factors involved in managing for amenity at four sites along two urban river corridors that have different biodiversity levels. I identify broad themes in public perceptions of amenity of urban river corridors through in-situ audio recordings and self-reported written responses and explore the relationship between these themes and differing levels of biodiversity. My findings improve our understanding of how people experience urban river corridors and identify elements that contribute to their restorative value. I explore the role of sensory responses in perception formation and identify synergies and conflicts between perceived amenity and biodiversity. In the face of increased biodiversity loss and stress-induced human illnesses, understanding these relationships is important in defining effective policy and on-ground activities for urban rivers that meet the needs of public land management, the public and ecology

Measurement of Linear Stark Interference in 199Hg

We present measurements of Stark interference in the 6$^1S_0$ $\rightarrow$ 6$^3P_1$ transition in $^{199}$Hg, a process whereby a static electric field $E$ mixes magnetic dipole and electric quadrupole couplings into an electric dipole transition, leading to $E$-linear energy shifts similar to those produced by a permanent atomic electric dipole moment (EDM). The measured interference amplitude, $a_{SI}$ = $(a_{M1} + a_{E2})$ = (5.8 $\pm$ 1.5)$\times 10^{-9}$ (kV/cm)$^{-1}$, agrees with relativistic, many-body predictions and confirms that earlier central-field estimates are a factor of 10 too large. More importantly, this study validates the capability of the $^{199}$Hg EDM search apparatus to resolve non-trivial, controlled, and sub-nHz Larmor frequency shifts with EDM-like characteristics.Comment: 4 pages, 4 figures, 1 table; revised in response to reviewer comment