| Enabling design and interactive selection of haptic modes | | BIBAK | Full-Text | 1-13 | |
| Karljohan Lundin; Matthew Cooper; Anders Persson; Daniel Evestedt | |||
| The ever increasing size and complexity of volumetric data in a wide range
of disciplines makes it useful to augment volume visualization tools with
alternative modalities. Studies have shown that introducing haptics can
significantly increase both exploration speed and precision. It is also capable
of conveying material properties of data and thus has great potential to
improve user performance in volume data exploration. In this paper we describe
how recent advances in volume haptics can be used to build haptic modes --
building blocks for haptic schemes. These modes have been used as base
components of a toolkit allowing for more efficient development of haptic
prototypes and applications. This toolkit allows interactive construction,
configuration and fine-tuning of both visual and haptic representations of the
data. The technology is also used in a pilot study to determine the most
important issues and aspects in haptic volume data interaction and exploration,
and how the use of haptic modes can facilitate the implementation of effective
haptic schemes. Keywords: Volume haptics; Haptic modes; Toolkit; User study | |||
| Generating 3D interaction techniques by identifying and breaking assumptions | | BIBAK | Full-Text | 15-21 | |
| Jeffrey S. Pierce; Randy Pausch | |||
| Researchers have created 3D interaction techniques for immersive virtual
worlds, but existing techniques represent just part of the design space. While
exploring other parts of the design space might yield more effective
techniques, conducting that exploration is difficult and time-consuming.
Analyzing the particular task, user, and hardware characteristics for any given
problem is straightforward, but only suggests the shape of a potential
technique; generating the technique itself still requires a creative
breakthrough. We propose extending existing approaches to generating 3D
interaction techniques by focusing more explicitly on identifying and breaking
assumptions about the real world to inspire potential technique ideas. We
describe our approach, suggest an initial list of assumptions to consider, and
present a case study of applying the process to create a technique for
navigation with visible landmarks and place representations. Keywords: Virtual reality; 3D interaction; Interaction techniques; Generative methods | |||
| An augmented reality interface for visualizing and interacting with virtual content | | BIBAK | Full-Text | 23-43 | |
| Fotis Liarokapis | |||
| In this paper, a novel AR interface is proposed that provides generic
solutions to the tasks involved in augmenting simultaneously different types of
virtual information and processing of tracking data for natural interaction.
Participants within the system can experience a real-time mixture of 3D
objects, static video, images, textual information and 3D sound with the real
environment. The user-friendly AR interface can achieve maximum interaction
using simple but effective forms of collaboration based on the combinations of
human-computer interaction techniques. To prove the feasibility of the
interface, the use of indoor AR techniques are employed to construct innovative
applications and demonstrate examples from heritage to learning systems.
Finally, an initial evaluation of the AR interface including some initial
results is presented. Keywords: Augmented reality; Human-computer interaction; Tangible interfaces; Virtual
heritage; Learning systems | |||
| Touch-enabled haptic modeling of deformable multi-resolution surfaces | | BIBAK | Full-Text | 45-60 | |
| Hanqiu Sun; Huawei Wang; Hui Chen; Kaihuai Qin | |||
| Currently, interactive data exploration in virtual environments is mainly
focused on vision-based and non-contact sensory channels such as
visual/auditory displays. The lack of tactile sensation in virtual environments
removes an important source of information to be delivered to the users. In
this paper, we propose the touch-enabled haptic modeling of deformable
multi-resolution surfaces in real time. The 6-DOF haptic manipulation is based
on a dynamic model of Loop surfaces, where the dynamic parameters are computed
easily without subdividing the control mesh recursively. A local deforming
scheme is developed to approximate the solution of the dynamics equations, thus
the order of the linear equations is reduced greatly. During each of the haptic
interaction loop, the contact point is traced and reflected to the rendering of
updated graphics and haptics. The sense of touch against the deforming surface
is calculated according to the surface properties and the damping-spring force
profile. Our haptic system supports the dynamic modeling of deformable Loop
surfaces intuitively through the touch-enabled interactive manipulation. Keywords: Haptics interface; Physics-based modeling; Subdivision surfaces | |||
| The effects of scent and game play experience on memory of a virtual environment | | BIBAK | Full-Text | 61-68 | |
| R. Tortell; D. P. Luigi; A. Dozois; S. Bouchard; J. F. Morie; D. Ilan | |||
| Scent has been well documented as having significant effects on emotion
(Alaoui-Ismaili in Physiol Behav 62(4):713-720, 1997; Herz et al. in Motiv Emot
28(4):363-383, 2004), learning (Smith et al. in Percept Mot Skills
74(2):339-343, 1992; Morgan in Percept Mot Skills 83(3)(2):1227-1234, 1996),
memory (Herz in Am J Psychol 110(4):489-505, 1997) and task performance (Barker
et al. in Percept Mot Skills 97(3)(1):1007-1010, 2003). This paper describes an
experiment in which environmentally appropriate scent was presented as an
additional sensory modality consistent with other aspects of a virtual
environment called DarkCon. Subjects' game play habits were recorded as an
additional factor for analysis. Subjects were randomly assigned to receive
scent during the VE, and/or afterward during a task of recall of the
environment. It was hypothesized that scent presentation during the VE would
significantly improve recall, and that subjects who were presented with scent
during the recall task, in addition to experiencing the scented VE, would
perform the best on the recall task. Skin-conductance was a significant
predictor of recall, over and above experimental groups. Finally, it was
hypothesized that subjects' game play habits would affect both their behavior
in and recall of the environment. Results are encouraging to the use of scent
in virtual environments, and directions for future research are discussed. Keywords: Virtual environments; Video games; Scent; Olfactory display; Emotion;
Arousal; Memory | |||
| The right of publicity in virtual reality | | BIB | Full-Text | 69-70 | |
| Woodrow Barfield | |||
| Virtual reality in the e-Society | | BIB | Full-Text | 71-73 | |
| G. D. Magoulas; G. Lepouras; C. Vassilakis | |||
| Opening new dimensions for e-Tourism | | BIBA | Full-Text | 75-87 | |
| Helmut Berger; Michael Dittenbach; Dieter Merkl; Anton Bogdanovych | |||
| In this paper we describe an e-Tourism environment that takes a community-driven approach to foster a lively society of travelers who exchange travel experiences, recommend tourism destinations or just listen to catch some interesting gossip. Moreover, business transactions such as booking a trip or getting assistance from travel advisors or community members are constituent parts of this environment. All these happen in an integrated, game-like e-Business application where each e-Tourist is impersonated as an avatar. More precisely, we apply 3D Electronic Institutions, a framework developed and employed in the area of multi-agent systems, to the tourism domain. The system interface is realized by means of a 3D game engine that provides sophisticated 3D visualization and enables humans to interact with the environment. We present "itchy feet", a prototype implementing this 3D e-Tourism environment to showcase first visual impressions. This new environment is a perfect research playground for examining heterogeneous societies comprising humans and software agents, and their relationship in e-Tourism. | |||
| Developing semantic VR-shops for e-Commerce | | BIBAK | Full-Text | 89-106 | |
| Olga De Troyer; Frederic Kleinermann; Haithem Mansouri; Bram Pellens | |||
| Increased bandwidth, cheaper and faster hardware, dedicated technology and
the success of e-commerce make VR-shops feasible. VR-shops are similar to the
e-shops currently available on the Web, with the difference that the products
are visualized as 3D objects in a virtual world. Although VR-shops do not
require sophisticated VR technology, they should be very flexible: it should be
easy to add, remove and rearrange products; and to add, change or remove
functionality. Therefore, an appropriate approach that can be used by a non-VR
expert and which provides a short development time and easy maintenance is
necessary. Also usability is very important because this is crucial for the
success of VR-shops. In this paper, we present an approach to develop VR-shops
that meet these requirements. It allows specifying a VR-shop using high-level
conceptual specifications and in terms of domain terminology; semantics are
captured by ontologies; existing product information can be incorporated; and
the actual code is generated. Keywords: VR-shops; e-Shops; Ontology; Semantics; Web services; Semantic annotation;
Semantic search engine; Shop-WISE | |||
| Applying virtual reality for trust-building e-commerce environments | | BIBAK | Full-Text | 107-127 | |
| Panagiota Papadopoulou | |||
| The application of virtual reality in e-commerce has enormous potential for
transforming online shopping into a real-world equivalent. However, the growing
research interest focuses on virtual reality technology adoption for the
development of e-commerce environments without addressing social and behavioral
facets of online shopping such as trust. At the same time, trust is a critical
success factor for e-commerce and remains an open issue as to how it can be
accomplished within an online store. This paper shows that the use of virtual
reality for online shopping environments offers an advanced customer experience
compared to conventional web stores and enables the formation of customer
trust. The paper presents a prototype virtual shopping mall environment,
designed on principles derived by an empirically tested model for building
trust in e-commerce. The environment is evaluated with an empirical study
providing evidence and explaining that a virtual reality shopping environment
would be preferred by customers over a conventional web store and would
facilitate the assessment of the e-vendor's trustworthiness. Keywords: Virtual reality; Electronic commerce; Trust; Agents | |||
| European virtual classrooms: building effective "virtual" educational experiences | | BIBAK | Full-Text | 129-143 | |
| Nicoletta Di Blas; Caterina Poggi | |||
| This paper presents Learning@Europe, an educational service, supported by
VR, that has involved in year 2004-2005 more than 1,000 students from 6
different European countries. L@E has fostered the creation/reinforcement of
three different kinds of communities: (1) the classroom community (reinforcing
the bonds among students, and between students and their teachers), (2)
communities among different schools competing together through 3D environments,
(3) a global community (roughly involving 20% of the total) of all the teachers
and students. A similar situation was created, at regional level, in the
Italian Region of Lombardy, involving nearly 800 individuals. Given that the
behaviours of the different communities in the two projects were very similar,
it seems to be arguable that a pattern of community building through virtual
environments has been detected. The important facts (detected by surveys of
teachers and students, inspection, direct observation, qualitative data
analysis) about these communities are: (1) the depth of the pedagogical impact,
in terms of increased knowledge (about history and related subjects), skills
(use of functional English, use of ICT in learning/teaching processes, group
work) and attitudes (more curiosity towards history, increased motivation in
school activities, improved respect and interest for other cultures). (2) The
engagement of all the participants, with very high level of customer
satisfaction. (3) The depth of the social impact, reinforcing existing
relationships (within the same class) and creating new ones. The key feature of
this success apparently lies in the sense of "social virtual presence", that
is, a feeling of being engaged in a virtual situation, so strong that the
technological means become "transparent" and the social situation (meant at
different levels and for different time frames) becomes "the king". The paper
will present the project, its main features and its outcomes, eventually
discussing the role of social virtual presence into building effective and
lively communities. Keywords: Virtual presence; Social presence; e-Learning; Virtual community;
Educational experience | |||
| Supporting participation in planning new roads by using virtual reality systems | | BIBAK | Full-Text | 145-159 | |
| Ilona Heldal | |||
| A road planning process runs through several phases, takes several years,
incorporates many decision-making procedures and includes numerous experts and
interest groups from different areas. Today, Virtual Reality (VR) systems can
benefit this process. By simulating different future alternatives, together
with their possible environmental impact, a common understanding of the
consequences of the respective alternatives can be obtained. Furthermore, since
many of the models are obtainable from the Internet, a wider public can be
reached already in the early phases of the planning process. The goal of the
paper is to provide a better understanding of the use of VR models for
supporting involvement and collaboration in the road planning process. The
background data are from two large road planning projects through cultural
heritage areas in Sweden. Observations on using VR models to support public
participation, and facilitate communication between different interested
parties, are presented. The results argue for the benefits of using VR models
during the whole road planning process and shed further light on a range of
social issues associated with using this technology. Keywords: Virtual reality; Road planning process; Communication; Visualization; User
participation; Public; Collaborative decision | |||
| M2S maps: supporting real-world navigation with mobile VR | | BIBAK | Full-Text | 161-173 | |
| Xiaolong Zhang | |||
| Mobile devices are becoming increasingly integrated into our society. In
addition to entertaining people with applications like pervasive games, mobile
devices can also help to address cognitive challenges people face in the real
world. This paper, by drawing on research findings from cognitive psychology
and geography, explores a design to use mobile VR to help people overcome one
cognitive barrier in navigation, which is to establish the correspondence
between 2D spatial information found in maps and 3D entities they perceive from
the real world. The design offers users multi-format, multi-scale, and semantic
(M2S) maps, ranging from 2D maps to 3D immersive environments, and helps users
to connect 2D maps to the real world through 3D environments which are equipped
with semantic representation and animation techniques. Consequently, users can
apply various kinds of spatial knowledge, 2D or 3D, in understanding the real
world as well as assisting in navigation. This research enhances the design
repertoire of mobile VR, and suggests a way to integrate virtual environments
into people's real-world life by examining the cognitive implications of 3D
models on users' activities. Keywords: Virtual environments; Mobile computing; Multi-scale; Navigation; Spatial
cognition | |||
| Design of an emotional and social interaction paradigm for the animation of 3D characters: the case of a therapy for brain injured people (the mirror neuron paradigm) | | BIBAK | Full-Text | 175-184 | |
| María Lucila Morales-Rodriguez; Bernard Pavard | |||
| We propose an emotional and social interaction paradigm for the behavioural
animation of virtual characters. Our research focuses on the production of
verbal and paraverbal interactions between a human and a virtual character in
the context of virtual therapy. The aim of this project is to assess virtual
therapies for the rehabilitation of people with brain injuries caused by
cerebral vascular accidents. The therapeutic paradigm is based on the
neuroscience concept of "mirror neurones" which emphasise the perceptual side
in the process of recovering neural damage. In our paradigm, the patient
interacts with a virtual therapist (embodied autonomous agent) that guides and
encourages him in order to fulfil the drills. Furthermore and following the
"mirror neurone paradigm", the patient can only see his virtual hands (which
are handicapped). The virtual platform provides the patient with a vision of
his hands undertaking a movement that he cannot perform. Doing so, we expect
that the perception of this virtual movement may improve the recuperation
(mirror neurone paradigm). In this paper, we also introduce the notion of an
"intelligent emotional character" to produce a sense of social as well as
emotional immersion in order to improve the interaction between the patient and
the virtual therapist. We discuss the role of emotional interaction in the
context of virtual social interaction and in particular its reflexive
dimension. Finally, we present an architecture for the animation of virtual
characters based on a multidisciplinary approach to model the emotional and
social interaction. Keywords: Virtual character; Social immersion; Emotional and social interaction;
Virtual therapy; Motor rehabilitation | |||
| Special issue editorial | | BIB | Full-Text | 185-188 | |
| James Ritchie; Richard Dewar | |||
| Towards the development of a virtual environment-based training system for mechanical assembly operations | | BIBA | Full-Text | 189-206 | |
| John E. Brough; Maxim Schwartz; Satyandra K. Gupta; Davinder K. Anand | |||
| In this paper, we discuss the development of Virtual Training Studio (VTS), a virtual environment-based training system that allows training supervisors to create training instructions and allows trainees to learn assembly operations in a virtual environment. Our system is mainly focused on the cognitive side of training so that trainees can learn to recognize parts, remember assembly sequences, and correctly orient the parts during assembly operations. Our system enables users to train using the following three training modes: (1) Interactive Simulation, (2) 3D Animation, and (3) Video. Implementing these training modes required us to develop several new system features. This paper presents an overview of the VTS system and describes a few main features of the system. We also report user test results that show how people train using our system. The user test results indicate that the system is able to support a wide variety of training preferences and works well to support training for assembly operations. | |||
| Desktop haptic virtual assembly using physically based modelling | | BIBAK | Full-Text | 207-215 | |
| Brad M. Howard; Judy M. Vance | |||
| This research investigates the feasibility of using a desktop haptic virtual
environment as a design tool for evaluating assembly operations. Bringing
virtual reality characteristics to the desktop, such as stereo vision, further
promotes the use of this technology into the every day engineering design
process. In creating such a system, the affordability and availability of
hardware/software tools is taken into consideration. The resulting application
combines several software packages including VR Juggler, open dynamics engine
(ODE)/open physics abstraction layer (OPAL), OpenHaptics, and OpenGL/GLM/GLUT
libraries to explore the benefits and limitations of combining haptics with
physically based modelling. The equipment used to display stereo graphics
includes a Stereographics emitter, Crystal Eyes shutter glasses, and a high
refresh rate CRT Monitor. One or two-handed force feedback is obtained from
various PHANTOM haptic devices from SensAble Technologies Inc. The
application's ability to handle complex part interactions is tested using two
different computer systems, which approximate the higher and lower end of a
typical engineer's workstation. Different test scenarios are analyzed and
results presented. Keywords: Haptic I/O; Computer-aided design; Physically based modelling; Virtual
reality | |||
| Industry case studies in the use of immersive virtual assembly | | BIBAK | Full-Text | 217-228 | |
| Sankar Jayaram; Uma Jayaram; Young Jun Kim; Charles DeChenne | |||
| In this paper, we report on two engineering case studies that have been
conducted as part of a Virtual Assembly Technology Consortium. The objectives
of the case studies were to determine if immersive virtual assembly
capabilities allow industry assembly situations to be modelled and studied
realistically, and to demonstrate the downstream value of the virtual assembly
capabilities in areas such as ergonomics, assembly installation, process
planning, installation, and serviceability. What is of special significance is
that instead of modelling simplified problems or perceived representative
situations, the case studies were constructed from actual assembly floor
projects and situations encountered at industry member sites and with
considerable participation from industry engineers and manufacturing shop floor
personnel. Based on the success of the case studies, the consortium members
inferred that virtual assembly methods are poised to move out of the realm of
special projects and test scenarios to deployment in the actual design and
manufacturing cycle. However, in order to be truly accepted in industry, there
are still issues to be addressed in terms of ease of use, portability of the
applications, and preparation of the models for the evaluations. Thus, the case
studies added a new dimension to the exploration and understanding of how this
new technology could be of practical value in industry. Keywords: Virtual assembly; Industry case study; VADE | |||
| 3D facial model exaggeration builder for small or large sized model manufacturing | | BIBAK | Full-Text | 229-239 | |
| Won-Sook Lee; Andrew Soon; Lijia Zhu | |||
| An action figure is a small human-shaped object used as a toy for children
or artistic collection. In the past, the creation of action figures required
intense manual effort. An initial trial to automate the process using recent
scanning technology failed to yield figures with market appeal because the
resulting action figures did not have sufficiently life-like shapes and
expressions. The limiting factor which was not considered during this trial is
the loss of individual characteristics resulting from either an increase or
reduction in scale. We provide novel techniques for creating an exaggerated
human face that retains all of the skin detail in the 3D scanned model, which
will allow more characteristic figures to be easily created at any scale,
thereby saving money and time during manufacturing. While traditional 3D
printing applications utilize rigid models acquired using computer-aided
design, our method demonstrates that deformable models (such as a human face)
obtained from scanners are also suitable. Keywords: 3D graphics; Virtual faces; 3D skin; Mesh parameterization; Exaggeration | |||
| Factors affecting user performance in haptic assembly | | BIBAK | Full-Text | 241-252 | |
| T. Lim; J. M. Ritchie; R. G. Dewar; J. R. Corney; P. Wilkinson; M. Calis | |||
| Current computer-aided assembly systems provide engineers with a variety of
spatial snapping and alignment techniques for interactively defining the
positions and attachments of components. With the advent of haptics and its
integration into virtual assembly systems, users now have the potential
advantage of tactile information. This paper reports research that aims to
quantify how the provision of haptic feedback in an assembly system can affect
user performance. To investigate human-computer interaction processes in
assembly modeling, performance of a peg-in-hole manipulation was studied to
determine the extent to which haptics and stereovision may impact on task
completion time. The results support two important conclusions: first, it is
apparent that small (i.e. visually insignificant) assembly features (e.g.
chamfers) affect the overall task completion at times only when haptic feedback
is provided; and second, that the difference is approximately similar to the
values reported for equivalent real world peg-in-hole assembly tasks. Keywords: Haptic assembly; Human-computer Interaction; Human factors; Design for
assembly; Peg-in-hole metrics; Virtual reality | |||
| Using the Semantic Web technologies in virtual engineering tools to create extensible interfaces | | BIBAK | Full-Text | 253-260 | |
| D. S. McCorkle; K. M. Bryden | |||
| Ideas and tools developed for the Semantic Web can also be applied to and
integrated with engineering tools and software. The ideas upon which the
Semantic Web are founded, along with the technologies that are used to
implement it, provide a platform on which virtual engineering tools and
interfaces can be extended to create a web in which contextual information is
readily accessible to engineers. When the Semantic Web and virtual engineering
methods are fully realized, computer hardware and networking capabilities will
work to provide information and tools to access information meaningfully. The
question that must be answered today is: how will information be integrated in
a manner that will allow commercial and proprietary software tools to remain
separate while also being integrated so that the end user can control and query
these tools with little to no knowledge of the tools' implementation or
inner-working details? The answer to this question will depend largely on the
ability to implement open interfaces and schemas that can evolve over time as
well as open source toolkits that enable development teams to collaborate at a
high level. This paper discusses potential applications of the Semantic Web to
explore these questions. In addition, specific capabilities being developed in
VE-Suite are discussed. Keywords: Virtual engineering; Semantic Web; Integration; Object oriented | |||
| Cable harness design, assembly and installation planning using immersive virtual reality | | BIBA | Full-Text | 261-273 | |
| James M. Ritchie; Graham Robinson; Philip N. Day; Richard G. Dewar | |||
| Earlier research work using immersive virtual reality (VR) in the domain of cable harness design has shown conclusively that this technology had provided substantial productivity gains over traditional computer-aided design (CAD) systems. The follow-on work in this paper was aimed at understanding the degree to which various aspects of the immersive VR system were contributing to these benefits and how engineering design and planning processes could be analysed in detail as they are being carried out; the nature of this technology being such that the user's activities can be non-intrusively monitored and logged without interrupting a creative design process or a manufacturing planning task. This current research involved the creation of a more robust CAD-equivalent VR system for cable harness routing design, harness assembly and installation planning which could be functionally evaluated using a set of creative design-task experiments to provide detail about the system and users' performance. A design task categorisation scheme was developed which allowed both a general and detailed breakdown of the design engineer's cable harness design process and associated activities. This showed that substantial amounts of time were spend by the designer in navigation (41%), sequence breaks (28%) and carrying out design-related activities (27%). The subsequent statistical analysis of the data also allowed cause and effect relationships between categories to be examined and showed statistically significant results in harness design, harness design modification and menu/model interaction. This insight demonstrated that poorly designed interfaces can have adverse affects on the productivity of the designer and that 3D direct manipulation interfaces have advantages. Indeed, the categorisation scheme provided a valuable tool for understanding design behaviour and could be used for comparing different design platforms as well as examining other aspects of the design function, such as the acquisition of design decision intent. The system also demonstrated the successful automatic generation of cable harness assembly and cable harness installation plans from non-intrusive user-system interaction logging, which further demonstrates the potential for concurrent design and manufacturing planning to be carried out. | |||
| Design evaluation and modification of mechanical systems in virtual environments | | BIBAK | Full-Text | 275-285 | |
| Csaba Antonya; Doru Talaba | |||
| Design is one of the most important stages in the manufacturing cycle and
influences all the subsequent stages of product development. In the context of
today's iterative design methodology, the modification of any design is a
process involving many evaluations and improvements to the solutions chosen in
earlier stages. For this purpose, in the most recent decade, 3D computer
simulations have become common tools used within industry. Whilst virtual
reality (VR) technology is seen as the interaction technology of the future,
much of the current research in this area is carried out to explore the
potential benefits and added value brought by the integration of this into
standard software technologies currently used at various stages in
manufacturing life cycle. A lot of attention has been given to exploring the
usability and benefits of interactive VR for assembly planning, knowledge
elicitation and design and simulation. However, little research has focussed on
the analytical aspects of the design process, for example in the use of VR as
an interface for simulation software in finite element methods and multi-body
systems. This paper introduces research focussing on applications of virtual
environments (VEs) for interactive design evaluation and modification adapted
and used with standard simulation software. The use of such interactive
visualisation offers the engineer more realistic real-time representations of
the design and advanced facilities to interact with the model during the design
process. While design evaluation is based mainly on visualisation; design
modification requires interactive changes of the model during the simulation,
and the interfaces described here highlights such applications. In this work,
two software prototypes have been developed using VR technology. First, a
software tool called design evaluation in virtual environments is presented
together with an application in civil engineering to illustrate the mode of
operation and added value of the use of an interactive visualisation
environment. Linking the simulation software with the VE provides real time
bi-directional communication of graphical information which can be successfully
achieved even within the limits of current computer technology. The tool
includes a suite of software modules and a user interface to facilitate the
link between the simulation results and the VE. The second tool facilitates the
design modification in virtual environments system by providing real time
dynamic simulation. Two dynamic approaches are investigated in order to study
the real time simulation issues in the context of design modification and
system performance: the classic approach based on rigid interconnected bodies,
and a new and novel approach developed by the authors based on particles
dynamics. Both implementations have been tested and compared on a mechanism
application under the same computing conditions. The research applications
presented demonstrate the practicality, flexibility and versatility of the
visualisation in virtual environment in design evaluation and modification.
However, the computer efficiency whilst carrying out real time dynamic
simulation is limiting the range of applications to models of moderate size;
however, this is an improvement on previous similar applications. Keywords: Design evaluation; Design modification; Multi-body system; Multi-particle
system; Virtual environment | |||
| The affect of contact force sensations on user performance in virtual assembly tasks | | BIBAK | Full-Text | 287-299 | |
| Samir Garbaya; U. Zaldivar-Colado | |||
| The development of a realistic virtual assembly environment is challenging
because of the complexity of the physical processes and the limitation of
available VR technology. Many research activities in this domain primarily
focused on particular aspects of the assembly task such as the feasibility of
assembly operations in terms of interference between the manipulated parts. The
virtual assembly environment reported in this research is focused on mechanical
part assembly. The approach presented addresses the problem of part-to-part
contacts during the mating phase of assembly tasks. The system described
calculates contact force sensations by making their intensity dependent on the
depth of penetration. However the penetration is not visible to the user who
sees a separate model, which does not intersect the mating part model. The two
3D models of the part, the off-screen rendered model and the on-screen rendered
model are connected by a spring-dumper arrangement. The force calculated is
felt by the operator through the haptic interface when parts come in contact
during the mating phase of the assembly task. An evaluation study investigating
the effect of contact force sensation on user performance during part-to-part
interface was conducted. The results showed statistically significant effect of
contact force sensation on user performance in terms of task completion time.
The subjective evaluation based on feedback from users confirmed that contact
force sensation is a useful cue for the operator to find the relative positions
of components in the final assembly state. Keywords: Virtual assembly; Spring-damper model; Haptic interface; Human performance | |||