상세정보

Unlike the past, users are able to access virtual reality systems more easily and conveniently, because of the rapid growth and wide spread of the wearable and portable devices that support virtual reality (VR). With these changes, designing user experience and interaction effectively in VR system is becoming a hot issue, especially since haptic interaction has emerged as a way to improve user experience of interacting with virtual objects and the utility range is gradually expanding. 
The richness of the haptic interaction hinges on the provision of sense of the kinesthetic (e.g. vs. mere contact). However, the practical implementation of haptic devices for kinesthetic feedback is still difficult due to the large size/weight, high complexity, and high cost of the equipment. Vibrotactile feedback is therefore an effective and economical alternative that can design haptic interaction when interacting with virtual objects, especially in the case of wearable or mobile systems. Despite its simplicity, it produces good results, when coordinated in a multimodal fashion with other associated feedback. Still, most vibrotactile interface employs only just one actuator and as such there is an inherent limitation in terms of providing enriched feedback and conveying diverse information. In particular, it is quite difficult to provide tactile interaction from out-of-body space with dynamic virtual object such as feeling a pulsating heart or holding on to a live animal due to moving at the mid-location. Therefore, it would be desirable for vibrotactile feedback to have the ability to express other aspects such as richer interactions with objects. In this area, not much research has been reported to this end, perhaps due to the mechanical limitations of vibrotactile device with which it is rather difficult to express kinesthetic dynamics.
In this thesis, we address taking advantage of the perceptual illusions to overcome these limitations and therefore propose a novel vibrotactile interaction method that provides high user experience even though system configuration is cost-effective, flexible and less mechanically complicated. In addition, we verify and evaluate usefulness of the proposed vibrotactile interaction technique by demonstrating actual application interacting with dynamic virtual object. The novel technique is to apply funneling and saltation that are well-known for tactile illusions and to extend them to interact with virtual objects as a new aspect which is out-of-body illusory tactile effects with visual feedback, so-called, virtual tactile feedback that can be tactile/touch interaction from out-of-body space or out-of-body illusory tactile interaction.
In this study, focusing particularly on out-of-body experience, we perform three sequential usability studies. The first, we verify the possibility of the out-of-body illusory tactile sensation through tactile illusions (funneling and saltation) with a visually rendered virtual object or without it respectively. Then, we investigate the possible synergistic effects by associating the illusory tactile sensation with various types of visual feedback and the way to interact with virtual object in practical application effectively. Finally, we design and evaluate practically the proposed interaction technique based on the out-of-body illusory tactile sensation for interacting a virtual/augmented object using a pinch gesture for actual usage. 
Our experimental study has revealed that the proposed interaction method was able to express dynamic movement of virtual object, presenting spatially virtual tactile feedback from out-of-body space where contact is not required between interface and user’s body even though it is attached only to the body parts (e.g., two fingertips), which has the advantage that can provide a high user experience with less effort and cost, as compared with the existing conventional method of tactile interaction in the VR systems. Therefore, it can be actively used in the interaction/interface design to improve user experience and applied to various fields, such as holograms and augmented reality. Also, the findings and results in the thesis are significant in terms of that they can be baseline data so as to design interaction based on illusion phenomenon.

ABSTRACT	i
CONTENTS	iv
List of Figures	vii
List of Tables	xiii
Chapter 1.	Introduction	1
 1.1 Motivation	1
 1.2 Background of Study and Approach	4
 1.3 Extending Out-of-Body Illusory Tactile Interaction with Virtual Object	7
 1.4 Thesis Aims	9
 1.5 Overview of Thesis Structure	11
Chapter 2.	Related Work	13
 2.1 Introduction	13
 2.2 Tactile Interaction	13
 2.3 Tactile Illusion	15
  2.3.1 Funneling	16
  2.3.2 Saltation	18
  2.3.3 Apparent Motion	19
 2.4 Applying Tactile Illusions to Human Interface	20
 2.5 Out-of-Body Illusory Tactile Sensation	22
 2.6 Summary	23
Chapter 3.	Existence of Out-of-Body Illusory Tactile Sensation with Virtual Object	25
 3.1 Exp. 1: Out-of-Body Tactile Illusion from Body-Extending Virtual Object	25
  3.1.1 Exp. 1(A): Funneling Effect for Virtual Body-Extending Objects	25
  3.1.2 Exp. 1(B): Saltation Effect for Virtual Body-Extending Objects	33
  3.1.3 Conclusion and Discussion	40
 3.2 Exp. 2: Out-of-Body Tactile Illusion from Virtual Source-Interaction Object	41
  3.2.1 Exp. 2(A): Effect of Virtual Source-Interaction Object for Funneling	42
  3.2.2 Exp. 2(B): Effect of Virtual Source-Interaction Object for Saltation	51
  3.2.3 Conclusion and Discussion	57
Chapter 4.	Investigation of Visual Effects on Out-of-Body Illusory Tactile Sensation	59
 4.1 Experiments and Hypotheses	59
 4.2 Exp. 3(A): Effects for Four Visual Feedback Types with Funneling	61
  4.2.1 Participants	61
  4.2.2 Experimental Design and Setup	61
  4.2.3 Detailed Procedure	64
  4.2.4 Results	66
 4.3 Exp. 3(B): Effects for Four Visual Feedback Types with Saltation	70
  4.3.1 Participants	70
  4.3.2 Experimental Design and Setup	70
  4.3.3 Detailed Procedure	71
  4.3.4 Results	74
 4.4 Conclusion and Discussion	79
Chapter 5.	Design and Evaluation of Out-of-body Illusory Tactile Interaction for Application	82
 5.1 Exp. 4(A): Out-of-Body Sensation between Two Fingers with Funneling	82
  5.1.1 Purposes	82
  5.1.2 Participants	83
  5.1.3 Experimental Design and Setup	83
  5.1.4 Detailed Procedure	85
  5.1.5 Results	88
 5.2 Exp. 4(B): Rich Pinch User Experience	92
  5.2.1 Purposes	92
  5.2.2 Participants	93
  5.2.3 Experimental Design and Setup	93
  5.2.4 Detailed Procedure	94
  5.2.5 Results	96
 5.3 Conclusion and Discussion	99
Chapter 6.	Conclusions and Future Work	100
 6.1 Conclusions	100
 6.2 Discussion	102
 6.3 Future Work	103
References 	105