A taxonomy and comparison of haptic actions for disassembly tasks

The usefulness of modern day haptics equipment for virtual simulations of actual maintenance actions is examined. In an effort to categorize which areas haptic simulations may be useful, we have developed a taxonomy for haptic actions. This classification has two major dimensions: the general type of action performed and the type of force or torque required. Building upon this taxonomy, we selected three representative tasks from the taxonomy to evaluate in a virtual reality simulation. We conducted a series of human subject experiments to compare user performance and preference on a disassembly task with and without haptic feedback using CyberGlove, Phantom, and SpaceMouse interfaces. Analysis of the simulation runs shows Phantom users learned to accomplish the simulated actions significantly more quickly than did users of the CyberGlove or the SpaceMouse. Moreover a lack of differences in the post-experiment questionnaire suggests that haptics research should include a measure of actual performance speed or accuracy rather than relying solely on subjective reports of a device’s ease of use

Nuclear Plants and Emergency Virtual Simulations Based on a Low-Cost Engine Reuse

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Nuclear Plants and Emergency Virtual Simulations based on a Low-cost Engine Reuse

Our industrialised society comprises many industrial processes that are very important for everyone, in a wide range of fields. Activities related to these industrial processes, though, involve, in higher or lower degrees, some risk for personnel,  besides risk for the general public in some cases. Therefore, efficient training programs and simulations are highly required, to improve the processes involved, increasing safety for people. To cite an example, nuclear plants pose high safety requirements in operational and maintenance routines, to keep plants in safe operation conditions and reduce personnel exposure to radiation dose. Besides operational and maintenance in nuclear plants, there are also other situations where efficient training is required, as in evacuation planning from buildings in emergency situations. Also, rescue tasks play similar role. These apply specially for nuclear sites. Another situation that requires efficient training is security, what has special meaning for plants that involve dangerous materials, such as nuclear plants. Nuclear materials must be kept under high security level, to avoid any misuse

The Virtual Mitten: A novel interaction paradigm for visuo-haptic manipulation of objects using grip force

International audienceIn this paper, we propose a novel visuo-haptic interaction paradigm called the "Virtual Mitten" for simulating the 3D manipulation of objects. Our approach introduces an elastic handheld device that provides a passive haptic feedback through the fingers and a mitten interaction metaphor that enables to grasp and manipulate objects. The grasping performed by the mitten is directly correlated with the grip force applied on the elastic device and a supplementary pseudo-haptic feedback modulates the visual feedback of the interaction in order to simulate different haptic perceptions. The Virtual Mitten allows natural interaction and grants users with an extended freedom of movement compared with rigid devices with limited workspaces. Our approach has been evaluated within two experiments focusing both on subjective appreciation and perception. Our results show that participants were able to well perceive different levels of effort during basic manipulation tasks thanks to our pseudo-haptic approach. They could also rapidly appreciate how to achieve different actions with the Virtual Mitten such as opening a drawer or pulling a lever. Taken together, our results suggest that our novel interaction paradigm could be used in a wide range of applications involving one or two-hand haptic manipulation such as virtual prototyping, virtual training or video games

Assessment of haptics-based interaction for assembly tasks in virtual reality

This thesis examines the benefits of haptics-based interaction for performing assembly-related tasks in a virtual environment. A software application that combined freeware and open-source software development kits was developed and demonstrated principles of physics-based modeling in a haptics-enabled immersive virtual environment. A user study was designed to evaluate subjects in performing a series of experiments relevant to the assembly engineering process including weight recognition, part positioning, and assembly simulation. Each experiment featured a structure based on factorial combinations of effects, resulting in a series of designed trials. Methods of assessing user performance were established based on task completion time and accuracy. Using a randomized complete block design, a sample population of forty individuals performed all trials within the experiments in random sequences. Statistical methods were used to analyze the performances of individuals upon the conclusion of the study. When compared to visualsonly methods, the results show that haptics-based interaction is beneficial in improving performance including reduced completion times for weight comparisons, higher placement accuracy when positioning virtual objects, and steadier hand motions along threedimensional trajectories. Furthermore, the results indicate that the accuracy in weight identification is dependent on both the hand controlling the object and sensory modality used. The study was inconclusive in determining the affect of haptics-based interaction on completion times when positioning objects or completing manual assembly tasks

Taxonomy of Human Actions for Action-based Learning Assessment in Virtual Training Environments

This design research project developed and validated a taxonomy of human actions to be used in action-based learning assessment. The taxonomy, titled ‘BEHAVE,’ was shown to have both internal and external validity and allows actions performed by learners, for example in digital performance spaces, to be formally represented with consistency and to be compared with expert reference actions, to generate automated post-performance formative feedback

Nuclear Power

The world of the twenty first century is an energy consuming society. Due to increasing population and living standards, each year the world requires more energy and new efficient systems for delivering it. Furthermore, the new systems must be inherently safe and environmentally benign. These realities of today's world are among the reasons that lead to serious interest in deploying nuclear power as a sustainable energy source. Today's nuclear reactors are safe and highly efficient energy systems that offer electricity and a multitude of co-generation energy products ranging from potable water to heat for industrial applications. The goal of the book is to show the current state-of-the-art in the covered technical areas as well as to demonstrate how general engineering principles and methods can be applied to nuclear power systems