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Virtual Reality 11

Dates:2007
Volume:11
Publisher:Springer-Verlag
Standard No:ISSN 1359-4338 (print) EISSN 1434-9957 (online)
Papers:24
Links:link.springer.com | Twitter | Table of Contents
  1. VR 2007-03 Volume 11 Issue 1
  2. VR 2007-06 Volume 11 Issue 2/3
  3. VR 2007-10 Volume 11 Issue 4

VR 2007-03 Volume 11 Issue 1

Enabling design and interactive selection of haptic modes BIBAKFull-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 BIBAKFull-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 BIBAKFull-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 BIBAKFull-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 BIBAKFull-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 BIBFull-Text 69-70
  Woodrow Barfield

VR 2007-06 Volume 11 Issue 2/3

Virtual reality in the e-Society BIBFull-Text 71-73
  G. D. Magoulas; G. Lepouras; C. Vassilakis
Opening new dimensions for e-Tourism BIBAFull-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 BIBAKFull-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 BIBAKFull-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 BIBAKFull-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 BIBAKFull-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 BIBAKFull-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) BIBAKFull-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

VR 2007-10 Volume 11 Issue 4

Special issue editorial BIBFull-Text 185-188
  James Ritchie; Richard Dewar
Towards the development of a virtual environment-based training system for mechanical assembly operations BIBAFull-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 BIBAKFull-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 BIBAKFull-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 BIBAKFull-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 BIBAKFull-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 BIBAKFull-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 BIBAFull-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 BIBAKFull-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 BIBAKFull-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