Browsing by Author "Chan, Liwei"

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Designing Skin-Dragging Haptic Motions for Wearables
(2017-01-01)
Je, Seungwoo
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Choi, Okyu
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Choi, Kyungah
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Lee, Minkyeong
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Suk, Hyeon-Jeong
Skin-dragging is an emerging type of haptic feedback that coveys both precise spatial and temporal tactile cues through the motion of a small pin dragged across the skin. While past research focused on building skin-dragging wearable devices with different form-factors, and testing their feasibility, it is still unclear what the user's perception of such haptic stimuli is, and how designers should generate dragging motionpatterns for informative feedback to be presented on a finger. In this work, we attempt to answer these questions. We therefore asked designers to create dragging motions using changes of speed, direction and length. We then tested the generated skin-dragging motions with a haptic smart-ring, classified them and extracted guidelines that can be used to convey rich and informative feedback on the fingers.
DLWV2: a Deep Learning-based Wearable Vision-system with Vibrotactile-feedback for Visually Impaired People to Reach Objects
(2018-01-01)
Shih, Meng-Li
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Chen, Yi-Chun
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Tung, Chia-Yu
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Sun, Cheng
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Cheng, Ching-Ju
We develop a Deep Learning-based Wearable Vision-system with Vibrotactile-feedback (DLWV2) to guide Blind and Visually Impaired (BVI) people to reach objects. The system achieves high accuracy in object detection and tracking in 3-D using an extended deep learning-based 2.5D detector and a 3-D object tracker with the ability to track 3-D object locations even outside the camera field-of-view. We train our detector with a large number of images with 2.5D object ground-truth (i.e., 2-D object bounding boxes and distance from the camera to objects). A novel combination of HTC Vive Tracker with our system enables us to automatically obtain the ground-truth labels for training while requiring very little human effort to set up the system. Moreover, our system processes frames in real-time through a client-server computing platform such that BVI people can receive realtime vibrotactile guidance. We conduct a thorough user study on 12 BVI people in new environments with object instances which are unseen during training. Our system outperforms the non-assistive guiding strategy with statistic significance in both time and the number of contacting irrelevant objects. Finally, the interview with BVI users confirms that our system with distance-based vibrotactile feedback is mostly preferred, especially for objects requiring gentle manipulation such as a bottle with water inside.
Dwell plus : Multi-Level Mode Selection Using Vibrotactile Cues
(2017-01-01)
Liao, Yi-Chi
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Chen, Yen-Chiu
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Chan, Liwei
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Chen, Bing-Yu
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交大名義發表
We present Dwell+, a method that boosts the effectiveness of typical dwell selection by augmenting the passive dwell duration with active haptic ticks which promptly drives rapid switches of modes forward through the user's skin sensations. In this way, Dwell+ enables multi-level dwell selection using rapid haptic ticks. To select a mode from a button, users dwell-touch the button until the mode of selection is haptically prompted. Our haptic stimulation design consists of a short 10ms vibrotacile feedback that indicates a mode arriving and a break that separates consecutive modes. We first tested the effectiveness of 170ms, 150ms, 130ms, and 110ms intervals between modes for a 10-level selection. The results reveal that 3-beats-per-chunk rhythm design, e.g., displaying longer 25ms vibrations initially for all three modes, could potentially achieve higher accuracy. The second study reveals significant improvement wherein a 94.5% accuracy was achieved for a 10-level Dwell+ selection using the 170ms interval with 3 beats-per-chunk design, and a 93.82% rate of accuracy using the more frequent 150ms interval with similar chunks for 5 level selection. The performance of conducting touch and receiving vibration from disparate hands was investigated for our final study to provide a wider range of usage. Our applications demonstrated implementing Dwell+ across interfaces, such as text input on a smartwatch, enhancing touch space for HMDs, boosting modalities of stylus-based tool selection, and extending the input vocabulary of physical interfaces.
FacePush: Experiencing Pressure Forces on Face with HMDs
(2018-01-01)
Chang, Hong-Yu
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Tseng, Wen-Jie
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Tsai, Chia-En
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Chen, Hsin-Yu
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Peiris, Roshan Lalintha
FacePush: Introducing Normal Force on Face with Head-Mounted Displays
(2018-01-01)
Chang, Hong-Yu
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Tseng, Wen-Jie
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Tsai, Chia-En
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Chen, Hsin-Yu
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Peiris, Roshan Lalintha
This paper presents FacePush, a Head-Mounted Display (HMD) integrated with a pulley system to generate normal forces on a user's face in virtual reality (VR). The mechanism of FacePush is obtained by shifting torques provided by two motors that press upon a user's face via utilization of a pulley system. FacePush can generate normal forces of varying strengths and apply those to the surface of the face. To inform our design of FacePush for noticeable and discernible normal forces in VR applications, we conducted two studies to identify the absolute detection threshold and the discrimination threshold for users' perception. After further consideration in regard to user comfort, we determined that two levels of force, 2.7 kPa and 3.375 kPa, are ideal for the development of the FacePush experience via implementation with three applications which demonstrate use of discrete and continuous normal force for the actions of boxing, diving, and 360 guidance in virtual reality. In addition, with regards to a virtual boxing application, we conducted a user study evaluating the user experience in terms of enjoyment and realism and collected the user's feedback.
FaceWidgets: Exploring Tangible Interaction on Face with Head-Mounted Displays
(2019-01-01)
Tseng, Wen-Jie
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Wang, Li-Yang
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Chan, Liwei
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資訊工程學系
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Department of Computer Science
We present FaceWidgets, a device integrated with the back-side of a head-mounted display (HMD) that enables tangible interactions using physical controls. To allow for near range-to-eye interactions, our first study suggested displaying the virtual widgets at 20 cm from the eye positions, which is 9 cm from the HMD backside. We propose two novel interactions, widget canvas and palm-facing gesture, that can help users avoid double vision and allow them to access the interface as needed. Our second study showed that displaying a hand reference improved performance of face widgets interactions. We developed two applications of FaceWidgets, a fixed-layout 360 video player and a contextual input for smart home control. Finally, we compared four hand visualizations against the two applications in an exploratory study. Participants considered the transparent hand as the most suitable and responded positively to our system.
ForceClicks: Enabling Efficient Button Interaction with Single Finger Touch
(2017-01-01)
Yong, Sangeon
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Chan, Liwei
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Lee, Edward Jangwon
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Nam, Juhan
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Peiris, Roshan
ForceClicks is a novel touch button input technique for consecutive clicking which incorporates touch force sensors. From force data of a single continuous touch over time, ForceClicks detects peaks and generates discrete clicks. Compared to typical button interaction, this is effective in a sense that consecutive clicks do not require finger positional movements. Additionally, stable force over a certain time threshold can trigger an alternate state, long press, and can be mapped to other actions. The usability of ForceClicks has been evaluated in terms of a) scattering level and b) efficiency. Results suggest higher stability than typical touch, especially when the task requires visual engagement on remote content. The relatively scatter-free characteristic of ForceClicks allows it to be applied on rapid clicking while gaming, and reduce of visual dedication allows easier control of external devices, and two applications, a shooting game and a number picker, are presented for demonstration.
FrontFace: Facilitating Communication Between HMD Users and Outsiders Using Front-Facing-Screen HMDs
(2017-01-01)
Chan, Liwei
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Minamizawa, Kouta
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交大名義發表
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National Chiao Tung University
A head-mounted display (HMD) immerses users in a virtual world, but separates them from outsiders in the real world. We present FrontFace, which is a novel HMD that combines an eye-tracker with a front-facing screen, to lower the communication barrier between HMD users and outsiders. The front-facing screen reveals user attention (e.g., the users eye motions) and user presence in the virtual or real world by displaying the scene in the virtual world or a skin background respectively, enabling eye-contact interactions between the HMD user and the outsiders. FrontFace has the following benefits. Firstly, it communicates the presence of the HMD user to outsiders; secondly, it reveals the player's visual attention by introducing the HMD users originally occluded eye motions, enabling outsiders to make sense of the HMD user's reaction in the virtual world or the real world. Three interactive techniques for the outsiders to initiate communication to HMD users are proposed: they are tap-trigger, hand-gesture trigger, and voice-trigger interactions. A small focus group provided feedback.
HapticSphere: Physical Support To Enable Precision Touch Interaction in Mobile Mixed-Reality
(2019-01-01)
Wang, Chiu-Hsuan
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Hsieh, Chen-Yuan
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Yu, Neng-Hao
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Bianchi, Andrea
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Chan, Liwei
This work presents I lapticSphere, a wearable spherical surface enabled by bridging a finger and the head-mounted display (HMD) with a passive string. Users perceive a physical support on a finger attached to a string, when extending their arm and reaching out to the string's maximum extension. This physical support assists users in precise touch interaction in the context of stationary and walking virtual or mixed-reality experiences. We propose three methods of attachment of the haptic string (directly on the head or on the body), and illustrate a novel single-step calibration algorithm that supports these configurations by estimating a grand haptic sphere, once a head-coordinated touch interaction is established. Two user studies were conducted to validate our approach and to compare the touch performance with physical support in sitting and walking conditions in the context of mobile mixed-reality scenarios. The results show that, in the walking condition, touch interaction with physical support significantly outperformed the visual-only condition.
LiquidReality: Wetness Sensations on the Face for Virtual Reality
(2018-01-01)
Peiris, Roshan Lalintha
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Chan, Liwei
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Minamizawa, Kouta
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交大名義發表
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National Chiao Tung University
We present LiquidReality, a wearable system that simulates wetness sensations directly on the user's face for immersive virtual reality applications. The LiquidReality system consists of a headmounted display integrated with thermal and vibrotactile modules that provides co-located haptic feedback with the displayed visuals. With this system, we conducted a preliminary study that evaluated nine types of thermal and thermal/vibrotactile stimuli to induce a wetness sensation on the user's face. Our results indicate that thermal only stimuli and low frequency vibrotactile stimuli (combined with thermal) induced better wetness perception. Next, using the results from this preliminary study, we evaluated the immersion enhancement when using the LiquidReality system in combination with related visuals. The results indicate that using the LiquidReality system with related visuals, enhances the level of immersion for the user.
One-Handed Input Through Rotational Motion for Smartwatches
(2018-01-01)
Tsai, Hsin-Ruey
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Chen, Po-Chang
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Chan, Liwei
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Hung, Yi-Ping
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資訊工程學系
One-handed input for smartwatches is crucial when users' hands are occupied. A rotational motion is leveraged, which can be detected by built-in motion sensors in most smartwatches, as input to provide item selection. Users control a cursor by rotating the smartwatch into different orientations using the proposed item selection gestures. To understand human wrist dexterity and the ability to perform rotational motion input along each degree of freedom on smartwatches, a human-factor study was performed. Except dexterity, users' consensus and agreement of user-defined rotational motion input gestures for selection and commitment on smartwatches in an exploratory user study were also observed. Based on both the studies, gestures roll and tilt are proposed as selection gestures, and shake and nod are used as commitment gestures. The item selection performance using the proposed gestures in 2D layouts in a user study was further evaluated. The study results showed that tilt-nod and tilt-shake are suitable for item numbers (4x3) and (5x5), respectively. Furthermore, due to high error rate for tilt-shake in (2x2) caused by false positive in shake detection, roll-shake with better social acceptance can be used as an alternative for smartwatches without a built-in front camera in (2x2).
Outside-In: Visualizing Out-of-Sight Regions-of-Interest in a 360 Video Using Spatial Picture-in-Picture Previews
(2017-01-01)
Lin, Yung-Ta
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Liao, Yi-Chi
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Teng, Shan-Yuan
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Chung, Yi-Ju
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Chan, Liwei
360-degree video contains a full field of environmental content. However, browsing these videos, either on screens or through head-mounted displays (HMDs), users consume only a subset of the full field of view per a natural viewing experience. This causes a search problem when a region-of-interest (ROI) in a video is outside of the current field of view (FOV) on the screen, or users may search for non-existing ROIs. We propose Outside-In, a visualization technique which reintroduces off-screen regions-of-interest (ROIs) into the main screen as spatial picture-in-picture (PIP) previews. The geometry of the preview windows further encodes a ROI's relative location vis-a-vis the main screen view, allowing for effective navigation. In an 18-participant study, we compare Outside-In with traditional arrow-based guidance within three types of 360-degree video. Results show that Outside-In outperforms in regard to understanding spatial relationship, the storyline of the content and overall preference. Two applications are demonstrated for use with Outside-In in 360-degree video navigation with touchscreens, and live telepresence.
PhantomLegs: Reducing Virtual Reality Sickness Using Head-Worn Haptic Devices
(2019-01-01)
Liu, Shi-Hong
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Yu, Neng-Hao
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Chan, Liwei
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Peng, Yi-Hao
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Sun, Wei-Zen
Virtual Reality (VR) sickness occurs when exposure to a virtual environment causes symptoms that are similar to motion sickness, and has been one of the major user experience barriers of VR. To reduce VR sickness, prior work has explored dynamic field-of-view modification and galvanic vestibular stimulation (GVS) that recouples the visual and vestibular systems. We propose a new approach to reduce VR sickness, called PhantomLegs, that applies alternating haptic cues that are synchronized to users' footsteps in VR. Our prototype consists of two servos with padded swing arms, one set on each side of the head, that lightly taps the head as users walk in VR. We conducted a three -session, multi -day user study with 30 participants to evaluate its effects as users navigate through a VR environment while physically being seated. Results show that our approach significantly reduces VR sickness during the initial exposure while remaining comfortable to users.
PokeRing: Notifications by Poking Around the Finger
(2018-01-01)
Je, Seungwoo
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Lee, Minkyeong
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Kim, Yoonji
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Chan, Liwei
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Yang, Xing-Dong
Smart-rings are ideal for subtle and always-available haptic notifications due to their direct contact with the skin. Previous researchers have highlighted the feasibility of haptic technology in smart-rings and their promise in delivering noticeable stimulations by poking a limited set of planar locations on the finger. However, the full potential of poking as a mechanism to deliver richer and more expressive information on the finger is overlooked. With three studies and a total of 76 participants, we informed the design of PokeRing, a smart-ring capable of delivering information via stimulating eight different locations around the index finger's proximal phalanx We report our evaluation of the performance of PokeRing in semi-realistic wearable conditions, (standing and walking), and its effective usage for information transfer with twenty-one spatio-temporal patterns designed by six interaction designers in a workshop. Finally, we present three applications that exploit PokeRing's notification usages.
Pull-Ups: Enhancing Suspension Activities with Body-Scale Kinesthetic Force Feedbacks for Virtual Reality
(2019-01-01)
Ye, Yuan-Syun
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Chen, Hsin-Yu
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Chan, Liwei
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資訊工程學系
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Department of Computer Science
We present Pull-Ups, a suspension kit that can suggest a range of body postures and thus enables various exercise styles of users perceiving the kinesthetic force feedback by suspending their weight with arm exertion during the interaction. Pull-Ups actuates the user's body to move up to 15 cm by pulling his or her hands using a pair of pneumatic artifcial muscle groups. Our studies informed the discernible kinesthetic force feedbacks that were then exploited for the design of kinesthetic force feedback in three physical activities: kitesurfng, paragliding, and space invader. Our fnal study on user experiences suggested that a passive suspension kit alone added substantially to users' perceptions of realism and enjoyment (all above neutral) with passive physical support, while suffcient active feedback can further level them up. In addition, we found that both passive and active feedback of the suspension kit signifcantly reduced motion sickness in simulated kitesurfng and paragliding compared to when no suspension kit (thus no feedback) was provided. This work suggests that a passive suspension kit is cost-effective as a home exercise kit, while active feedback can further level up user experience, though at the cost of the installation (e.g., an air compressor in our prototype).
PuPoP: Pop-up Prop on Palm for Virtual Reality
(2018-01-01)
Teng, Shan-Yuan
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Kuo, Tzu-Sheng
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Wang, Chi
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Chiang, Chi-huan
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Huang, Da-Yuan
The sensation of being able to feel the shape of an object when grasping it in Virtual Reality (VR) enhances a sense of presence and the ease of object manipulation. Though most prior works focus on force feedback on fingers, the haptic emulation of grasping a 3D shape requires the sensation of touch using the entire hand. Hence, we present Pop-up Prop on Palm (PuPoP), a light-weight pneumatic shape-proxy interface worn on the palm that pops several airbags up with predefined primitive shapes for grasping. When a user's hand encounters a virtual object, an airbag of appropriate shape, ready for grasping, is inflated by way of the use of air pumps; the airbag then deflates when the object is no longer in play. Since PuPoP is a physical prop, it can provide the full sensation of touch to enhance the sense of realism for VR object manipulation. For this paper, we first explored the design and implementation of PuPoP with multiple shape structures. We then conducted two user studies to further understand its applicability. The first study shows that, when in conflict, visual sensation tends to dominate over touch sensation, allowing a prop with a fixed size to represent multiple virtual objects with similar sizes. The second study compares PuPoP with controllers and freehand manipulation in two VR applications. The results suggest that utilization of dynamically-changing PuPoP, when grasped by users in line with the shapes of virtual objects, enhances enjoyment and realism. We believe that PuPoP is a simple yet effective way to convey haptic shapes in VR.
SeeingHaptics: Visualizations for Communicating Haptic Designs
(2019-01-01)
Chan, Liwei
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Chen, Mu-Hsuan
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Ho, Wen-Chi
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Peiris, Roshan Lalintha
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Chen, Bing-Yu
Rendering haptic feedback in virtual reality is a common approach to enhancing the immersion of virtual reality content. However, current editing tools allow developers to access the haptic feedback only through physical contact with the actuators, making it difficult to fast iterate haptic interaction designs. This paper introduces SeeingHaptics, an authoring tool which visualizes haptic properties in 3D scenes. The active area of certain feedback is simulated with mesh shapes, while the 2D icons allow for indicating the type of haptic sensation. Our evaluation showed that SeeingHaptics helps developers rapidly create haptic feedbacks after a short training session.
ShareSpace: Facilitating Shared Use of the Physical Space by both VR Head-Mounted Display and External Users
(2018-01-01)
Yang, Keng-Ta
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Wang, Chiu-Hsuan
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Chan, Liwei
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資訊工程學系
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Department of Computer Science
Currently, "walkable" virtual reality (VR) is achieved by dedicating a room-sized space for VR activities, which is not shared with non-HMD users engaged in their own activities. To achieve the goal of allowing shared use of space for all users while overcoming the obvious difficulty of integrating use with those immersed in a VR experience, we present ShareSpace, a system that allows external users to communicate their needs for physical space to those wearing an HMD and immersed in their VR experience. ShareSpace works by allowing external users to place "shields" in the virtual environment by using a set of physical shield tools. A pad visualizer helps this process by allowing external users to examine the arrangement of virtual shields. We also discuss interaction techniques that minimize the interference between the respective activities of the HMD wearers and the other users of the same physical space. To evaluate our design, a user study was conducted to collect user feedback from participants in four trial scenarios. The results indicate that our ShareSpace system allows users to perform their respective activities with improved engagement and safety. In addition, this study shows that while the HMD users did perceive a considerable degree of interference due to the internal visual indications from the ShareSpace system, they were still more engaged in their VR experience than when interrupted by direct external physical interference initiated by external users.
tactoRing: A Skin-Drag Discrete Display
(2017-01-01)
Je, Seungwoo
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Rooney, Brendan
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Chan, Liwei
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Bianchi, Andrea
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資訊工程學系
Smart rings are an emerging wearable technology particularly suitable for discrete notifications based on haptic cues. Previous work mostly focused on tactile actuators that stimulate only specific skin receptors on the finger, resulting in limited information expressiveness. We propose tactoRing, a novel tactile display that, by dragging a small tactor on the skin around the finger, excites multiple skin areas resulting in more accurate cue recognition. In this paper we present the hardware and a perception study to understand the ability of users to recognize eight distinct points around the finger. Moreover, we show two different techniques to encode information through skin-dragging motion with accuracy up to 94%. We finally showcase a set of applications that, by combining sequences of tactile stimuli, achieve higher expressiveness than prior methods.
ThermalBracelet : Exploring Thermal Haptic Feedback Around the Wrist
(2019-01-01)
Peiris, Roshan Lalitha
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Feng, Yuan-Ling
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Chan, Liwei
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Minamizawa, Kouta
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交大名義發表
Smartwatches enable the wrist to be used as an ideal location to provide always-available haptic notifications as they are constantly worn with direct contact with the skin. With the wrist straps, the haptic feedback can be extended to the full space around the wrist to provide more spatial and enhanced feedback. With Thermal Bracelet, we investigate thermal feedback as a haptic feedback modality around the wrist. We present three studies that lead to the development of a smartwatch-integratable thermal bracelet that stimulates six locations around the wrist. Our initial evaluation reports on the selection of the thermal module configurations. Secondly, with the selected six-module configuration, we explore its usability in real-world scenarios such as walking and reading. Thirdly, we investigate its capability of providing spatio temporal feedback while engaged in distracting tasks. Finally we present application scenarios that demonstrates its usability.