Production systems empowered by digital simulation tools can be improved in a time and cost-effective approach. The enrichment of digital simulations with sensor data, can enhance their realism and...

The digital twin implementation for linking the virtual representation of human-based production tasks to their physical counterpart in the factory-floor

We investigated the instructional effectiveness of using an interactive and immersive virtual reality (IVR) simulation versus a video for teaching scientific knowledge in 2 between-subjects experiments. In Experiment 1, 131 high school students (84 females) used a science simulation that involved forensic analysis of a collected DNA sample in a virtual laboratory environment rendered in IVR or as a video covering the same material. In Experiment 2, 165 high school students (111 females) replicated the experiment with approximately half of each group being asked to engage in the generative learning strategy of enactment after the lesson—that is, carrying out the learned procedures with concrete manipulatives. Across both experiments, the IVR groups reported significantly higher perceived enjoyment and presence than the video group. However, no significant differences were found between media for procedural knowledge in Experiment 1 and 2, or transfer in Experiment 2. Also, there was no difference in declarative knowledge across media in Experiment 1, and there was a media effect favoring video in Experiment 2 (ηp² = 0.028). Enactment lead to significantly better procedural knowledge (ηp² = 0.144) and transfer (ηp² = 0.088) in the IVR group but not in the video group. In conclusion, learning in IVR is not more effective than learning with video but incorporating generative learning strategies is specifically effective when learning through IVR. The results suggest that the value of IVR for learning science depends on how it is integrated into a classroom lesson. (PsycInfo Database Record (c) 2021 APA, all rights reserved)

Immersive virtual reality increases liking but not learning with a science simulation and generative learning strategies promote learning in immersive virtual reality.

Wearable Soft Technologies for Haptic Sensing and Feedback

In virtual reality, the lack of kinesthetic feedback often prevents users from experiencing the weight of virtual objects. Control-to-display (C/D) ratio manipulation has been proposed as a method to induce weight perception without kinesthetic feedback. Based on the fact that lighter (heavier) objects are easier (harder) to move, this method induces an illusory perception of weight by manipulating the rendered position of users' hands---increasing or decreasing their displayed movements. In a series of experiments we demonstrate that C/D-ratio induces a genuine perception of weight, while preserving ownership over the virtual hand. This means that such a manipulation can be easily introduced in current VR experiences without disrupting the sense of presence. We discuss these findings in terms of estimation of physical work needed to lift an object. Our findings provide the first quantification of the range of C/D-ratio that can be used to simulate weight in virtual reality.

Pseudo-Haptic Weight: Changing the Perceived Weight of Virtual Objects By Manipulating Control-Display Ratio

Motion Analysis System (MAS) for production and ergonomics assessment in the manufacturing processes

Virtual reality (VR) technology strives to enable a highly immersive experience for the user by including a wide variety of modalities (e.g. visuals, haptics). Current VR hardware however lacks a sufficient way of communicating the perception of weight of an object, resulting in scenarios where users can not distinguish between lifting a bowling ball or a feather. We propose a solely software based approach of simulating weight in VR by deliberately using perceivable tracking offsets. These tracking offsets nudge users to lift their arm higher and result in a visual and haptic perception of weight. We conducted two user studies showing that participants intuitively associated them with the sensation of weight and accept them as part of the virtual world. We further show that compared to no weight simulation, our approach led to significantly higher levels of presence, immersion and enjoyment. Finally, we report perceptional thresholds and offset boundaries as design guidelines for practitioners.

Breaking the Tracking: Enabling Weight Perception using Perceivable Tracking Offsets

Augmented and virtual reality (AR/VR) has entered the mass market and, with it, will soon eye tracking as a core technology for next generation head-mounted displays (HMDs). In contrast to existing gaze interfaces, the 3D nature of AR and VR requires estimating a user's gaze in 3D. While first applications, such as foveated rendering, hint at the compelling potential of combining HMDs and gaze, a systematic analysis is missing. To fill this gap, we present the first design space for gaze interaction on HMDs. Our design space covers human depth perception and technical requirements in two dimensions aiming to identify challenges and opportunities for interaction design. As such, our design space provides a comprehensive overview and serves as an important guideline for researchers and practitioners working on gaze interaction on HMDs. We further demonstrate how our design space is used in practice by presenting two interactive applications: EyeHealth and XRay-Vision.

A Design Space for Gaze Interaction on Head-mounted Displays

Including haptic feedback in current consumer VR applications is frequently challenging, since technical possibilities to create haptic feedback in consumer-grade VR are limited. While most systems include and make use of the possibility to create tactile feedback through vibration, kinesthetic feedback systems almost exclusively rely on external mechanical hardware to induce actual sensations so far. In this paper, we describe an approach to create a feeling of such sensations by using unmodified off-the-shelf hardware and a software solution for a multi-modal pseudo-haptics approach. We first explore this design space by applying user-elicited methods, and afterwards evaluate our refined solution in a user study. The results show that it is indeed possible to communicate kinesthetic feedback by visual and tactile cues only and even induce its perception. While visual clipping was generally unappreciated, our approach led to significant increases of enjoyment and presence.

Conveying the Perception of Kinesthetic Feedback in Virtual Reality using State-of-the-Art Hardware

On the Use of Multi-Depth-Camera Based Motion Tracking Systems in Production Planning Environments

While we perceive time as a constant factor in the real world, it can be manipulated in media. Being quite easy for linear media, this is used for various aspects of storytelling e.g., by applying slow motion in movies or TV. Interactive media like VR however poses additional challenges, because user interaction speed is independent from media speed. While it is still possible to change the speed of the environment, for interaction it is also necessary to deal with the emerging speed mismatch, e.g., by slowing down visual feedback of user movements. In this paper, we explore the possibility of such manipulations of visual cues, with the goal of enabling the use of slow motion also in immersive interactive media like VR. We conducted a user study to investigate the impact of limiting angular velocity of a virtual character in first person view in VR. Our findings show that it is possible to use slow motion in VR while maintaining the same levels of presence, enjoyment and susceptibility to motion sickness, while users adjust to the maximum speed quickly. Moreover, our results also show an impact of slowing down user movements on their time estimations.

Florian Geiselhart

Papers

Breaking the Tracking: Enabling Weight Perception using Perceivable Tracking Offsets

A Design Space for Gaze Interaction on Head-mounted Displays

Conveying the Perception of Kinesthetic Feedback in Virtual Reality using State-of-the-Art Hardware

On the Use of Multi-Depth-Camera Based Motion Tracking Systems in Production Planning Environments

The matrix has you: realizing slow motion in full-body virtual reality