Stable haptic interaction using the Excalibur force display

This paper studies a new sensorial approach to improving communication between partners during collaborative tasks taking place in abstract and non-visual virtual reality environments. The sensorial approach was investigated in the context of the search and identification of targets in a simplified 2D environment. It consists in finding a spatial configuration corresponding to a defined criterion such as a maximum, minimum, or defined score. During the collaborative search, users need to be aware of their results and also the results of their partners. In addition, they need to compare examined scores (e.g., docking score or physical value) with other results to make decisions. To support these features, an audio---haptic display was developed employing binaural audio with an intermodal stimuli synthesis design to improve the collaborative search. This rendering tool allows for simultaneous use of the audio and haptic channels which enables an efficient individual search and comparison of results. In addition, it improves the communication and activity coordination between the partners. An experiment was carried out to evaluate the contribution of the tool to improve the collaborative search of targets in a 2D non-visual environment. The results clearly show a significant improvement in performance and working efficiency with the audio---haptic display as compared to a traditional haptic-only condition. Moreover, we observed a reduction in the need for verbal communication during some steps of the search process. However, this approach introduces some communication conflicts during the steps presenting high-level interactions between partners which reduce the working efficiency of some groups.

Encountered-Type Haptic Displays (ETHDs) represent a field of haptic displays with the premise of not using any type of actuator directly in contact with the user skin, thus providing an alternative integration of haptic displays in virtual environments. In this paper, we present novel interaction techniques (ITs) dedicated to ETHDs. The techniques aim at addressing the issues commonly presented for these devices such as limited contact areas, lags and unexpected collisions with the user. First, our paper proposes a design framework based on several parameters defining the interactive process between user and ETHD (input, movement control, displacement and contact). Five techniques based on different ramifications of the design space framework were conceived, respectively named: Swipe, Drag, Clutch, Bubble and Follow. Then, a use-case scenario was designed to depict the usage of these techniques on the task of touching and coloring a wide, flat surface. Finally, a user study based on the coloring task was conducted to assess the performance and user experience for each IT. Results were in favor of Drag and Clutch techniques which are based on manual surface displacement, absolute position selection and intermittent contact interaction. Taken together our results and design methodology pave the way to the design of future ITs for ETHDs in virtual environments.

Impedance-type kinesthetic haptic displays aim to render arbitrary desired dynamics to a human operator using force feedback. To render realistic virtual environments, the difference between desired and rendered dynamics must be small. In this paper, we analyze the closed-loop dynamics of haptic displays for three common virtual environments: a spring, a damper, and a spring-damper, including the effects of time delay and low-pass filtering. Using a linear model, we identify important parameters for the rendered dynamics in terms of effective impedances, a conceptual tool that decomposes the displays closed-loop impedance into components with physical analogs. Our results establish bandwidth limits for rendering effective stiffness and damping. The effective stiffness bandwidth is limited by the virtual stiffness and device mass, and the effective damping bandwidth is limited by the cut-off frequency of the low-pass filter which filters the device velocity estimate. We show that a general system impedance can be characterized by a mass, damper, and spring optimally by the solution to a convex optimization problem, and we present a quantitative metric, the Average Distortion Error (ADE), to describe the fidelity of this model. Time delay has no significant effect on characterized stiffness, and reduces characterized damping by the product of virtual stiffness and total time delay. Reducing the low-pass filter cut-off frequency reduces the characterized damping. Experimental data gathered with a Phantom Premium 1.5 validates the theoretical analysis. We also conducted human user experiments to investigate the effects of time delay and low-pass filtering on perceived stiffness and damping. Similar to the characterized dynamics results, we observed no significant effect of time delay on perceived stiffness, and increasing time delay resulted in reduced perceived damping. Lower filter cut-off frequencies resulted in lower perceived damping. This work informs haptic display design by presenting how closed-loop behavior changes with key parameters.

Often, designers and developers of serious games (and virtual simulations in general) strive for high fidelity (realism). However, real-time high-fidelity rendering of complex environments across sensory modalities such as vision, audition, and haptic (sense of touch) is still beyond our computational reach. Previous work has demonstrated that multimodal effects can be considerable, to the extent that a large amount of detail of one sense may be ignored or enhanced by the presence of other sensory inputs. Taking advantage of such multimodal effects, perceptual-based rendering—whereby the rendering parameters are adjusted based on the perceptual system—can be employed to limit computational processing. Motivated by the general lack of emphasis given to the understanding of audio rendering in virtual environments and games, we have started investigating multimodal (audiovisual) interactions within such virtual environments. Our work has shown that sound can directly affect visual fidelity perception and task performance within a virtual environment. These effects can be very individualized, whereby the influence of sound is dependent on various individual factors including musical listening preferences, suggesting the importance of individualizing the virtual environment to each user. This chapter begins with an overview of virtual environments and serious gaming’s open problems, with an emphasis on fidelity, and multimodal interactions, and the implications that these may have on performance and computational requirements. A detailed summary of our own prior work will be provided along with insight and suggestions that may guide designers and developers of serious games and virtual learning environments in general. Although the chapter is contextualized in the use of serious games in health professions education, the information provided is generalizable across a variety of domains.

Pain and discomfort are perceptible during many medical procedures. In the past, drugs have been the conventional means to alleviate pain, but in many instances, medications by themselves do not provide optimal results. Current advances are being made to control pain by integrating both the science of pain medications and the science of the human mind. Various psychological techniques, including distraction by virtual reality environments and the playing of video games, are being employed to treat pain. In virtual reality environments, an image is provided for the patient in a realistic, immersive manner devoid of distractions. This technology allows users to interact at many levels with the virtual environment, using many of their senses, and encourages them to become immersed in the virtual world they are experiencing. When immersion is high, much of the user's attention is focused on the virtual environment, leaving little attention left to focus on other things, such as pain. In this way virtual reality provides an effective medium for reproducing and/or enhancing the distractive qualities of guided imagery for the majority of the population who cannot visualize successfully.

To date, haptic interfaces have rarely been used to display complex virtual environments such as those involving 3D mechanical assembly operations, or the use of hand tools. Of the limitations which have been encountered, one is the absence of suitable simulation techniques which provide a general, user-defined virtual environment. This paper discusses the use of an impulse-based simulation as a general purpose multibody simulator for haptic display. This technique uses Poisson’s hypothesis in conjunction with Coulomb friction as the basis of the contact model. Since haptic displays are required to run in real time with a constant step size and high update rate, changes to the algorithm are required. We identify the “impact state” as a critical feature of the contact model, and outline the various ways it can be chosen. Finally, we describe the implementation of a planar multibody simulator on one and two-axis haptic displays.

This brief article reports on the use of virtual reality and its effectiveness on improving and maintaining learners' intrinsic motivation or interest. Research suggests that interest contributes to learning. Therefore a study of the impact of interests is essential to an understanding of intrinsic motivation. Since the virtual environment provides a sense of presence, it may be possible to create scenarios to stimulate the learners' curiosity and interest. Eighteen students, 11 males and 7 females, between 21 and 32 years old, served as subjects for the study. The experiment consisted of the physical world environment using wooden blocks, and the virtual world using virtual blocks. Both worlds used color and shape as variables. The two variables consisted of three shapes (sphere, pyramid, and cube), and three colors (red, green, and blue). In both worlds, the wooden blocks and virtual blocks had to be manipulated and arranged in nine different patterns. The first experiment started with a two-block pattern. At each step the difficulty was increased by increasing the number of blocks. The subject's score was based on a ten-point scale instrument administered at the end of each experiment. The scores ranged from very weak to very strong. The results were used to identify a significant difference between the subjects' performance in the virtual world and in physical world with respect to curiosity, interest, and sense of control. The interest level comparison indicated that for all subjects scores in the virtual world were always higher than the scores in the physical world. The sense of control level comparison indicated that in the beginning scores in the virtualworld were not always higher than the scores in the physical world. However, after orientation to navigation through the virtual environment, the mean score gradually rose. This research demonstrates that the virtual world is more useful than the physical world (with respect of color and shape) in increasing the memory span of the learner.

Over the past decade, wide-area distributed computing has emerged as a powerful computing paradigm. Virtual machines greatly simplify wide-area distributed computing by lowering the abstraction to benefit both resource users and providers. A virtual execution environment consisting of virtual machines (VMs) interconnected with virtual networks provides opportunities to dynamically optimize, at run-time, the performance of existing, unmodified distributed applications without any user or programmer intervention. We have formalized the adaptation problem in virtual execution environments and shown that it is NP-hard to both, solve and approximate within a factor of m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2-δ</sup> for any δ > 0, where m is the number of edges in the virtual overlay graph. We also designed and evaluated greedy adaptation algorithms and found them to work well in practice.

This study proposed a low‐cost, easy to set up and easy to modify virtual classroom simulation environment, CartoonClass , and tested its impact on 27 pre‐service primary school teachers' noticing development during a semester‐long mathematics methods course. The participants' perceptions of using CartoonClass were also examined. A Wilcoxon signed‐rank test of the pre‐test and post‐test results showed that the participants (1) significantly developed their noticing skills, with regard to both general classroom events and attending‐to skills; and (2) significantly changed their focus on ‘mathematics thinking,’ an accepted indicator of better noticing skills. (3) However, a novel video‐summarising task aimed at detecting the participants' skills to quickly notice and grasp a complex teaching situation found no significant change in such ability over the course of the experiment. On the other hand, the qualitative data analysis showed the participants had positive perceptions of the virtual environment regarding realism, enjoyment and effectiveness. Practitioner notes What is already known about this topic Using virtual classroom simulations can improve pre‐service teachers' expertise, but teacher educators need a low‐cost virtual environment that can be easily used in their own classrooms. Our understanding of using classroom simulations to improve teacher noticing is still limited. Using animation‐based assessment in teacher noticing is meaningful. Examining teacher noticing relies much on written reflections of watching videos but developing different types of tasks is critical. What this paper adds This study provided an economical and easy way to build a virtual classroom environment. Compared with previous classroom simulation studies, this study used a more structured instrument to examine pre‐service teachers' noticing performance. A novel task (write a full‐video outline with a short time watching) was created to examine teachers' noticing skills in quickly recognising a classroom situation. Implications for practice and/or policy The two types of questions (general and specific) in assessing teacher noticing yielded different results that may provide valuable insights for future research on this topic. As our pre‐service teachers developed only basic noticing skills (ie, attending‐to), we suggest that teacher educators should be provided with more intensive training in teacher noticing. Developing only attending‐to skills may be not sufficient for quickly recognising a classroom situation.

Virtualization is the fundamental attribute of next generation network. Embedding customized virtual networks (VNs) onto the underlying physical network (PN) is the core issue in virtualization research. This issue is virtual network embedding (VNE). Since the issue inception, multiple mapping algorithms have been studied. However, prior mapping algorithms are mostly static. Existing dynamic mapping algorithms just focus on accepting as many VNs as possible. No existing dynamic algorithm considers optimizing the quality of service (QoS) performance of each accepted VN. On these backgrounds, we jointly investigate the dynamic VN embedding and optimize the QoS performance of each accepted VN. A dynamic heuristic algorithm is proposed in order to be evaluated in continuous time. When one VN service is requested, the VN will be mapped by the dynamic heuristic algorithm. If the QoS demand of the VN is not guaranteed, the re-embedding scheme of the heuristic algorithm will be driven. Certain virtual elements of the VN will be re-embedded. The dynamic embedding algorithm ensures flexible VN assignment and improves the physical resource utilization. Finally, simulation results are illustrated in order to validate the strength of our proposed dynamic algorithm. For instance, VN acceptance ratio of our dynamic heuristic algorithm improves at least 13%.

Virtual environments have been widely adopted for design and training tasks in the industrial domain. Low-cost automation (LCA) is a technology that automatizes some activities using mostly standard automation mechanisms available off the shelf. However, LCA systems should adapt to existing standard production lines and workstations. Thus, workers must customize standard LCA templates and perform adaptation and customization steps. This activity can be very time consuming with physical LCA systems, and in case of errors, it may be necessary to rebuild many parts from scratch. Thus, LCA systems would greatly benefit from a design and prototyping step experienced in a virtual simulation environment. An immersive virtual reality (IVR) application for rapid and easy prototyping of LCA solutions has been investigated in previous work; the assessment of the system usability proved that the users highly appreciated the proposed solutions. This research explores further improvements to exploit the existing IVR application as a training tool for LCA prototyping trainees. The proposed application now provides users with two different interaction paradigms based on the VIVE controllers and the Manus Prime II data gloves. The application’s interface has been revised to allow a proper comparison of the two interaction models. The two interfaces have been compared, involving 12 participants in an LCA building task. The System Usability Scale (SUS) and the NASA Task Load Index (TLX) questionnaires have been used to assess the usability and workload of the two solutions.

Chapter 7 - Wearable haptics

The cloud computing is one of the most popular issues in recent years. Many service providers have provided the cloud solution using virtualization such as Amazon EC2. We are facing the new threats in the virtual environment. Since the virtual network is different to the traditional environment, we have to face with new threats that do not exist in the traditional network environment. In this paper, we provide a solution Virtual Network Guard System (VNGS) to solve the problems in virtual network that we face in the virtual environment. We modify the network interface controller in the virtual environment to limit the guest operation system access rights. We also provide a centralize management server to deploy filtering processes and collect the alert information. Finally, we evaluate the performance of our system with normal network interface controllers, and the results shows that the performance is acceptable.KeywordsCloud SecurityPacket FilterVirtual Network Security System

We show a novel encountered‐type haptic system, H‐Wall, to enable haptic feedback using a manipulator of seven degrees of freedom suitable for simulating indoor virtual reality environments, which are characterized and confined by a set of vertical walls and revolving doors. At runtime, our system tracks hand motion using a red–green–blue depth sensor and locates its configuration. Then, the robotic manipulator plans a trajectory for the end effector, attached to a rectangular rigid board, to make contact with the hand to deliver a sense of touch as long as the perceived hand contact force is substantial. The force feedback is generated in a passive sense for static walls that the rigid board, corresponding to a vertical wall, holds its position as long as the perceived hand contact force is substantial. For a revolving door, the force feedback is generated in an active sense based on impedance control. In order to address the issue of limited workspace, we also propose a new reachability map, calledper‐plane reachability map, that is optimized to answer whether passive haptic feedback can be generated by a manipulator when the user touches a vertical wall at a given orientation. We successfully demonstrate our system to provide an illusion to the user in a virtual environment with touch sensation to the surrounding environment.

The physical and representational contents of the public space are in a dynamic evolving state with the changes in the social structure and urban structure. In the historical process, the phenomenon of public space has been affected by the developments experienced with the change in the way individuals establish relationships in public life. Today, this transformation has occurred through virtual networks with the development of information and communication technologies. The paper aims to understand the public sphere dynamics that have changed with information and communication technologies. Accordingly, it limits its scope on these questions: How virtual networks affect the representational form of public space? What are the spatial structuring of this new representational public realm? What effect does this transformation have on urban areas that are the physical spaces of public realm? The method of the study is to explain theoretical discussions by supporting examples. In this context, it has been found that virtual networks, known as a new form of public space, transform the representative and physical form of the public space in a multifaceted manner by relocating the way individuals communicate with each other on a virtual layer. In this virtual transformation, it has been seen that the representative public space is now formed on social networks and platforms and the spatial structuring of these areas is defined as virtual network. The effect of virtual networks on the physical spaces of the public realm is possible by clustering data about urban areas in these virtual environments. Therefore, the visibility of virtual networks on the physical spaces of the publicity takes place through the understanding of space usage; moreover, virtual network data, which hybridizes with contemporary urban areas, reveals new qualities in the sense of the city by embodying it through maps. The physical transformation of the public space with information and communication technologies is made possible by the use of virtual network data in the design processes of this new sensory city.