This paper presents a method to generate a haptic illusion of compliance using a vibrotactile actuator when a tangential force is applied to a rigid surface. The novel method builds on a conceptual ...compliance model where a physical object moves on a textured surface in response to a tangential force. The method plays vibration patterns simulating friction-induced vibrations as an applied tangential force changes. We built a prototype consisting of a two-dimensional tangential force sensor and a surface transducer to test the effectiveness of the model. Participants in user experiments with the prototype perceived the rigid surface of the prototype as a moving, rubber-like plate. The main findings of the experiments are: 1) the perceived stiffness of a simulated material can be controlled by controlling the force-playback transfer function, 2) its perceptual properties such as softness and pleasantness can be controlled by changing friction grain parameters, and 3) the use of the vibrotactile compliance feedback reduces participants' workload including physical demand and frustration while performing a force repetition task.
QR codes have been used as an inexpensive means to connect users to digital platforms such as websites and mobile applications. However, despite their ubiquity, QR codes are limited in purpose and ...can only redirect users to the URL contained within it, thereby making their use heavily network dependent which can be unsuitable for use in ephemeral scenarios and areas with limited connectivity. In this paper, we introduce Frappé, a framework capable of deploying ultra lightweight UIs to mobile devices directly through QR codes, without requiring any network connectivity. This is achieved by decomposing the UI into metadata and storing it inside the QR code, while offloading the UI functionality to API calls. We also introduce enFrappé, a WYSIWYG tool for building Frappé UIs. We demonstrate the lightweight nature of our framework through a technical evaluation, whereas the usability of our UI builder tool is demonstrated through a user study.
In today’s digital art applications, users can play virtual musical instruments or paint on virtual canvas using multi-touch input. Existing touch input devices, however, do not consider that the ...result of artistic expression changes depending on the material properties of the tool that comes into contact with the art medium. This paper proposes a novel method called MaterialSense that estimates the material properties of objects in contact with a touch input surface. The technique uses a commercial touchpad with six load cells attached, and when up to two objects are in contact, solves the force equilibrium equation to estimate the stiffness and friction coefficient of each contacted object. By analyzing the time-series data of the measured 3-axis force and normal vector for each touchpoint, it can estimate the stiffness and kinetic friction coefficient of the contacted object. Estimated material properties enable novel and realistic artistic expressions in touch-based digital art applications, such as changes in the tone of virtual instruments or the effects of different painting brushes. We present two application scenarios using MaterialSense, along with an in-depth technical evaluation to verify the accuracy and precision of its estimates.
•We propose a novel method called MaterialSense that estimates the material properties of objects (i.e., stiffness and friction coefficient) in contact with a touch input surface.•MaterialSense’s estimation performance is verified through careful technical evaluation.•Potential applications utilizing MaterialSense are proposed and demonstrated.
Foot-based gestures enable people to interact with mobile and wearable devices when their hands are unavailable for interaction. For the foot gestures to be truly usable, the gestures should be ...recognizable by the system without being confused by daily activities and still be easy to perform. However, designing such gestures often requires multiple iterations of gesture design, model training, and evaluation. In this paper, we present SequenceSense, a tool developed to help designers efficiently design a usable gesture set using inertial sensors, which eliminates the need for multiple data collection studies to evaluate the gestures’ usability through gesture modification by sequencing atomic actions and instant false positive analysis, and instead requires only the initial gesture sample collection. Unlike gesture recognizers using complete gestures to train a model, SequenceSense segments gesture into a sequence of atomic actions. For example, a foot tap to the right may have (1) lift the foot, (2) move the foot to the right, and (3) land the foot. SequenceSense also compares the gesture sequence with the sequence database created from the daily activities to identify possible conflicts. This allows gesture designers to build easily usable foot-based gestures without the need for recollecting and evaluating gestures. We validated SequenceSense’s efficacy in designing usable gestures with low false positives through a user study with nine gesture designers.
•Eliminates multiple data collection studies to design and build usable foot-gestures.•Supports sequencing of atomic actions for instant false positive analysis.•A user study with nine gesture designers shows the efficacy of the tool.
We present PseudoBend, a haptic feedback technique that creates the illusion that a rigid device is being stretched, bent, or twisted. The method uses a single 6-DOF force sensor and a vibrotactile ...actuator to render grain vibrations to simulate the vibrations produced during object deformation based on the changes in force or torque exerted on a device. Because this method does not require any moving parts aside from the vibrotactile actuator, devices designed using this method can be small and lightweight. Psychophysical studies conducted using a prototype that implements this method confirmed that the method could be used to successfully create the illusion of deformation and could also change users' perception of stiffness by changing the virtual stiffness parameters.
Wearable devices allow quick and convenient interactions for controlling mobile computers. However, these interactions are often device-dependent, and users cannot control devices in a way they are ...familiar with if they do not wear the same wearable device. This paper proposes a new method, UnifiedSense, to enable device-dependent gestures even when the device that detects such gestures is missing by utilizing sensors on other wearable devices. UnifiedSense achieves this without explicit gesture training for different devices, by training its recognition model while users naturally perform gestures. The recognizer uses the gestures detected on the primary device (i.e., a device that reliably detects gestures) as labels for training samples and collects sensor data from all other available devices on the user. We conducted a technical evaluation with data collected from 15 participants with four types of wearable devices. It showed that UnifiedSense could correctly recognize 5 gestures (5 gestures × 5 configurations) with an accuracy of 90.9% (SD = 1.9%) without the primary device present.
This study introduces RealityBrush, a novel augmented reality (AR) authoring system that allows designers to quickly and easily create realistic virtual objects by capturing and utilizing the kinetic ...properties of everyday physical objects in the early stages of design. The RealityBrush system consists of a handheld device, a data analysis module and an AR feedback module. The handheld device, which is made in the shape of a rod, is equipped with a depth camera and a force sensor at the tip. When a user holds the device and pokes a physical object, the local force applied to the object and the resulting deformations of the object are measured simultaneously. By analyzing the relationship between measured force and deformations, the RealityBrush system can identify two kinetic properties of the poked object: stiffness and motion resistance. The user can then use the handheld device as a 3D brush to create a virtual object in the air and assign the measured kinetic properties to the created virtual object. Finally, the system’s physics engine allows the user to interact with the created object by using the device to poke or push the object. The technical evaluation showed that the system can successfully extract the stiffness and motion resistance of everyday objects. We also report initial user feedback on AR authoring using the RealityBrush system.
Abstract
The QWERTY keyboard has been a de facto standard for computer text entry and continues to be one for mobile text entry such as for smartphones. It is not clear, however, that it will ...continue to be an option for text entry for much smaller devices such as smartwatches. In a series of user experiments, we examined the performance of the QWERTY keyboard when it is reduced to fit a small smartwatch screen. At the same time, we examined whether the ZoomBoard and the SplitBoard, which are QWERTY keyboards augmented by zooming and panning strategies, respectively, would be effective in comparison with a plain QWERTY keyboard. In Experiment 1, we evaluated the text entry performance of new users on the three QWERTY keyboards. In Experiment 2, we evaluated the relative performance of the three keyboards for three different screen sizes. In Experiment 3, we further observed how the keyboard performance changed when used in a mobile situation. Main results are: (i) users could adapt to a plain QWERTY keyboard even in the smallest screen cases. (ii) The SplitBoard consistently showed a better performance than other keyboards in all tested sizes. (iii) The SplitBoard showed a better performance than other keyboards in a mobile condition (treadmill) and was preferred most by participants.
You Watch, You Give, and You Engage Lu, Zhicong; Xia, Haijun; Heo, Seongkook ...
Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems,
04/2018
Conference Proceeding
Despite gaining traction in North America, live streaming has not reached the popularity it has in China, where live- streaming has a tremendous impact on the social behaviors of users. To better ...understand this socio-technological phenomenon, we conducted a mixed methods study of live streaming practices in China. We present the results of an online survey of 527 live streaming users, focusing on their broadcasting or viewing practices and the experiences they find most engaging. We also interviewed 14 active users to explore their motivations and experiences. Our data revealed the different categories of content that was broadcasted and how varying aspects of this content engaged viewers. We also gained insight into the role reward systems and fan group-chat play in engaging users, while also finding evidence that both viewers and streamers desire deeper channels and mechanisms for interaction in addition to the commenting, gifting, and fan groups that are available today.
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