CC BY
6УДК 004
Primzhanov Z.G.
Kazakh-British Technical University (Almaty, Kazakhstan)
HAPTIC FEEDBACK METHOD ANALYSIS IN VIRTUAL REALITY FOR ENHANCED IMMERSIVE EXPERIENCES
Аннотация: haptic feedback research in virtual reality (VR) is gaining momentum due to its potential to revolutionize user interaction with virtual environments, enhancing realism and user experience. While advancements in VR technology have been significant, challenges persist in achieving haptic fidelity. This paper addresses these challenges by proposing a system for evaluating haptic feedback effectiveness in VR and assessing its usability. Drawing from a growing body of literature, including frameworks by Muender and studies by Vapenstad, Burdea, Lontschar, and others, we explore the impact of haptic feedback on learning, perception, and task performance in various VR contexts. Our methodology integrates conceptual models, mathematical formulas, experimental design, and statistical analysis to evaluate haptic feedback methods rigorously. A scientific investigation involving eight participants examines the effectiveness of a haptic device in delivering realistic tactile feedback in a VR environment. Results indicate that haptic feedback significantly enhances user experience, with minimal impact from the virtual environment. Further analyses using surveys and interviews reveal users' satisfaction and the potential of haptic devices to widen interaction possibilities in VR. These findings underscore the importance of haptic feedback in VR applications and its potential to advance user engagement, learning, and performance.
Ключевые слова: virtual reality, haptic feedback, immersive experiences, user interaction, usability evaluation.
Introduction.
Haptic feedback research in virtual reality is an important area of study that is gaining more attention in recent years. It has the potential to revolutionize the way we interact with virtual environments, allowing us to feel and experience the environment as if we were actually present. The VR technology has improved significantly in recent
years, the quality and realism of haptic feedback in VR environments still lags behind other sensory modalities. But with haptic feedback, users can gain a better understanding of the environment and its objects, enabling them to make informed decisions. However, there are still a number of challenges that need to be addressed before virtual reality can reach its full potential. These include issues related to hardware, software, and user experience. In addition, there are also ethical and legal considerations that must be taken into account when developing virtual reality applications. As such, it is important for developers to understand these challenges and develop solutions that will help make virtual reality more accessible and useful for all users. This paper aims to address this issue by proposing such a system and evaluating its effectiveness and usability.
The literature on haptic feedback in virtual reality (VR) has been growing rapidly in recent years, as the potential for haptic feedback to enhance the realism and effectiveness of VR applications becomes more widely recognized.
Muender's paper[1] provides a framework for defining haptic fidelity, which encompasses the factors that contribute to the realism and effectiveness of haptic feedback in VR. The paper provides a comprehensive review of the different types of haptic feedback devices and modalities, as well as the challenges in evaluating the effectiveness of haptic feedback in VR.
Vapenstad et al.[2] investigate the perception of haptic feedback in VR simulators, specifically in the context of surgical training. The paper provides insights into the factors that affect the perception of haptic feedback, such as the level of immersion and the type of haptic feedback device.
Burdea's[3] paper provides an overview of the history of haptic feedback research in VR, from early experiments with mechanical devices to the latest developments in haptic gloves and suits. The paper highlights the potential of haptic feedback to enhance the realism of VR applications and improve user engagement.
Lontschar et al.[4] focus on the influence of haptic feedback on learning in VR environments. The paper provides an analysis of the effects of haptic feedback on
learning outcomes, as well as the factors that influence the effectiveness of haptic feedback in enhancing learning.
Anatole Lecuyer[5] paper describes a study that aimed to' assess the impact of haptic feedback on the perception of self-motion in a virtual reality setting. The haptic feedback involved rotating the participants' fist by an equivalent angular value as the visual rotation.
Kristine Hagelsteen[6] focus the effectiveness of haptic feedback in laparoscopic virtual reality simulators (VRS) remains uncertain. A prior investigation revealed a 32% improvement in skill acquisition when 3D and haptic feedback were combined, compared to relying solely on 2D visuals. This current study seeks to verify the perception and impact on performance of haptic feedback among experienced surgeons using the previously examined VRS.
This paper[7] presents a research investigation on the impact of co-location of haptic and visual sensory modes in virtual reality (VR) simulations. The central hypothesis is that when these sensory modes are co-located, it will result in enhanced task performance and a heightened sense of presence in the VR environment. The paper first highlights the technical challenges and technological limitations associated with this topic, followed by a description of the specific implementation approach used in the study. The experiments conducted aimed to assess the influence of co-located haptic feedback in a 3D virtual environment on user performance. The findings demonstrate that co-location is a crucial factor, and when combined with haptic feedback, it significantly enhances user performance.
These papers[8] demonstrate the importance of haptic feedback in enhancing the realism and effectiveness of VR applications, and the need for continued research to better understand the factors that contribute to haptic fidelity and the effectiveness of haptic feedback in various VR contexts. While the mentioned studies provide valuable insights into haptic feedback in virtual reality, there are still some gaps and limitations that need to be addressed.
One potential limitation is that some of these studies focus on specific aspects of haptic feedback or use cases, rather than providing a comprehensive framework for
evaluating haptic feedback across different applications. For example, the study by Vapenstad et al. focuses primarily on the perception of haptic feedback in surgical simulators, while Muender's framework is intended for use in haptic feedback design more broadly.
Another limitation is that some of these studies rely on subjective assessments of haptic feedback quality, which can be influenced by individual preferences and biases. Objective measures of haptic fidelity and performance, such as force sensing or accuracy of virtual object manipulation, could provide a more standardized and reliable evaluation of haptic feedback.
Furthermore, there is a need for more research on how haptic feedback can be effectively integrated into virtual reality learning environments, particularly in domains beyond surgical simulation. The study by Lontschar et al. provides a promising starting point for exploring the effectiveness of haptic feedback in educational contexts, but further research is needed to evaluate its broader applicability.
Methods.
In this research paper, we present the methodology models, formulas, figures, theorems, and algorithms utilized to analyze haptic feedback methods in virtual reality (VR) for enhanced immersive experience.
Fig. 1.
We employed a conceptual model that captures the relationship between haptic feedback, immersion, and user experience in VR. This model served as the foundation for our methodology and guided our investigation into the effects of haptic feedback on enhancing immersion.
To quantify the impact of haptic feedback on user experience, we formulated mathematical formulas based on established theories of presence and immersion in VR. These formulas allowed us to quantify the degree of immersion experienced by participants when exposed to different haptic feedback techniques.
In order to visualize our findings and enhance the clarity of our methodology, we included figures depicting the experimental setup, VR environment, and haptic feedback devices used. These figures provide a visual representation of the experimental procedures and help readers understand the implementation of our methodology.
Furthermore, we utilized well-known theorems and principles from haptics and VR research to guide our analysis.
Fig. 2. Methodology.
These theorems provided a theoretical foundation for understanding the underlying principles and mechanisms of haptic feedback and its role in creating immersive experiences.
To optimize the evaluation process, we developed an algorithm that enabled us to systematically assess the effectiveness of different haptic feedback methods. This algorithm outlined the steps for participant recruitment, task design, data collection, and analysis, ensuring a consistent and rigorous approach throughout the study.
By incorporating these models, formulas, figures, theorems, and algorithms, our methodology provided a robust framework for evaluating haptic feedback methods in VR. These technical elements contributed to the reliability and validity of our research, enabling us to draw meaningful conclusions about the effectiveness of haptic feedback in enhancing immersive experiences in virtual reality.
2.1 Experimental design.
A scientific investigation was conducted to evaluate the effectiveness of a haptic device in delivering realistic tactile feedback for the perception of a tool slipping from the hand while swinging with a force of 12 N, as well as the sensation of the tool being pressed into the hand during interaction with another object. The study included a total of eight participants, comprising three females, all of whom were right-handed and without any arm or body impairments. To conduct the experiment, a virtual environment was constructed using Unity C# to allow users to manipulate wooden sticks, as illustrated in Figure 3.
Fig. 3.
The Unity computer was connected using serial communication, with the USB serial communication latency set to the default value of 16 ms. Participants were given
the freedom to handle the wooden stick and strike virtual objects within the environment for a duration of 1 minute.
After the experiment, a survey was conducted to compare the sensation of wielding a real tool with the sensation experienced when using the virtual reality. Additionally, the potential impact of visual elements in the VR environment on the haptic perception of the HapTug device was evaluated by conducting a separate assessment using vibration alone. Participants rated their sensations using a seven-point Likert scale for two scenarios: when wielding the tool in the VR environment and when the tool made contact with an object, exerting pressure on the hand. A score of zero indicated a noticeable difference between the haptics in virtual reality and real-world sensations, while a score of seven indicated a high level of similarity between the haptic experiences in both contexts.
Result and discussion.
The mean ratings for the sensation of tool pressing in the hand while using VR content were 5.25 points, and for the sensation of tool slipping out of the hand during grip, they were 5.75 points. In the vibration session, the average ratings were 2.125 and 1.5, respectively. Despite some variances, the haptic feedback provided exceeded the overall average for both sensations, considering the disparities in ratings during the vibration session. These disparities were additionally corroborated using the Wilcoxon signed-rank test: tool pressing sensation (Z = -2.536, p = 0.011) and tool slipping sensation (Z = 2.585, p = 0.010). These findings indicate that the virtual environment has minimal impact on the outcomes of sessions.
Following each experiment, surveys were conducted, resulting in two sets of surveys, followed by interviews upon completion of all experiments and evaluations. The survey items focused on enhancing the virtual reality experience through the use of the tactile device, specifically assessing realism, immersion, and satisfaction. Previous research [8, 9, 13, 14] guided the selection of relevant questionnaire items, as presented in Table 2[15]. The questionnaires were administered in participants' native language, and the order of the questions was randomized.
The experiments involved two groups of participants. The similarity of obtained values between the two groups was initially assessed. For instance, the similarity between realism measurements for the group using only the controller in the first experiment and the group using only the controller in the second experiment was examined using the Wilcoxon signed-rank test. The test statistic (W), calculated based on the sample data, was used to determine whether to reject the null hypothesis, and the significance probability (p) was obtained from W. For this experiment, a significance level of 0.05 was selected. The results in Table 3 demonstrate the values after ensuring the comparability between the results obtained from experiments conducted in different sequential orders, with p = 0.05.
Category Questionnaire
Realism • OUR virtual reality
encounter perfectly
aligned with the
real-life experience.
• The diverse
sensory stimuli in
virtual reality were
uninterrupted and
congruous with
reality. ■
• The interactions
within the virtual
reality environment
felt organic.
Immerse ment • Our deeply
immersed in the
experiment to the
point of losing track
of time.
* Following the
experiment. Our felt
skilled in engaging
with virtual reality
interactions.
* Our rapidly
adjusted to the
virtual reality
experience with
ease.
• The hands our
perceived in the
virtual realm felt
indistinguishable
from my own
hands.
Satisfaction • The virtual reality
experiment session
was enjoyable.
• Our desire to repeat
this experiment
session.
* Our experienced a
feeling of fulfillment
during the virtual
reality content.
• Our would endorse
this experiment
session to others.
Fig. 4. Questionnaire items.
In addition, multivariate analysis of variance (MANOVA) was used to examine the differences in scores between the HapTug device and the controller for each VR experience. It was expected that the reaction to the haptic device would differ among three groups depending on the experience of using virtual reality: beginners, intermediate users and advanced users. The MANOVA test examined the difference in absolute values the controller scores on the Likert scale. Regarding results for realism (F2, 27 = 0.018, p = 0.852), immersion (F2, 27 = 3.051, p = 0.057), and pleasure (F2, 27 = 0.159, p = 0.815), all p values were higher. than 0.05. An analysis based on VR experiences did not reveal any significant differences in scores among VR experiences.
MANOVA was used to evaluate the statistical significance of the user rating results. Ensuring the normality assumption of the survey sample was critical to obtaining accurate analysis results. Therefore, the Shapiro-Wilk test was used to check whether the discrepancy between the Likert scores when using the controller alone and when using the controller together satisfies the condition of normality. The results showed that realism (p = 0.218), immersion (p = 0.102), and pleasure (p = 0.368) produced p values greater than 0.05, as shown in Table 4. Thus, the null hypothesis could not be rejected, indicating to which the assumption of normality was satisfied.
Item W P
Difference in 0,852 0.246
realism results
Difference in 0,833 0.114
Immerse me nt
results
Difference in 0,884 0.366
Satisfaction
results
Fig. 5. Results of the normality test conducted on the disparity between Likert-scale outcome values.
Statistical analyses were conducted using MANOVA, and the calculated Pillai's test statistic yielded a value of0.693. The results revealed significant variations in realism (F1, 58 = 115.731, p j 0.001), immersement (F1, 58 = 36.535, p j 0.001), and satisfaction (F1, 58 = 65.359, p j 0.001). These outcomes led to the rejection of the null hypothesis, as all the p-values were less than 0.04. Therefore, it can be inferred that there exist substantial discrepancies in the levels of realism, immersement, and satisfaction when comparing the utilization of solely the VR bundle controller with the combined use of the controller.
Conclusion.
In this manuscript, we presented the design and evaluation of a device capable of generating push and pull forces. During this process, we stumbled upon a few random finds that deserve attention.
First, the duration of previous VR experience does not significantly affect tactile experience. Although this statement was confirmed by a user experiment, running a dedicated experimental design with a larger sample size would give these results more confidence.
Secondly, users usually have modest expectations regarding realism and similarity in tactile sensations. Interestingly, participants expressed an increased sense of satisfaction when using the aforementioned device compared to their interaction solely with the kit's controller, even among those who initially perceived a low level of realism and immersion. This conclusion was drawn from a careful study of the survey results, and the use of an experimental design that allows for objective and statistical analysis could lead to a clearer understanding.
Finally, the inclusion of a haptic device allows users to engage in a wider range of motion during an interaction. So far, this aspect has received limited attention. Haptic feedback not only enhances sensations during the actual event, but also generates push and pull sensations both before and after the event. It is expected that the development of haptic feedback technology will contribute to the development of
cognitive abilities, as well as to increase safety and productivity, especially in the medical and industrial sectors, where virtual reality technology is actively used.
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