Wearable vibrotactile systems for virtual contact and information display

This paper presents a development history of a wearable, scalable vibrotactile stimulus delivery system. This history has followed a path from desktop-based, fully wired systems, through hybrid approaches consisting of a wireless connection from the host computer to a body-worn control box and wires to each tactor, to a completely wireless system employing Bluetooth technology to connect directly from the host to each individual tactor unit. Applications for such a system include delivering vibrotactile contact cues to users of virtual environments, providing directional cues in order to increase situational awareness in both real and virtual environments, and for general information display in wearable contexts. Through empirical study, we show that even a simple configuration, such as eight tactors arrayed around the torso, can be effective in increasing situational awareness in a building-clearing task, compared to users who perform the same task without the added cues.     

Tactile interfaces: technologies,applications and challenges

Tactile interfaces are used to communicate information through the sense of touch, which is an area of growing interest in the research community. Potential applications include virtual training for surgeons, remotely touching materials via the Internet, automotive industry, active interfaces for blind persons, and sensory substitution devices.     

A systematic approach to the Kansei factors of tactile sense regarding the surface roughness

Designing products to satisfy customers' emotion requires the information gathered through the human senses, which are visual, auditory, olfactory, gustatory, or tactile senses. By controlling certain design factors, customers' emotion can be evaluated, designed, and satisfied. In this study, a systematic approach is proposed to study the tactile sense regarding the surface roughness. Numerous pairs of antonymous tactile adjectives are collected and clustered. The optimal number of adjective clusters is estimated based on the several criterion functions. The representative average preferences of the final clusters are obtained as the estimates of engineering parameters to control the surface roughness of the commercial polymer-based products.     

图像局部纹理特性的静电力触觉渲染

目的 触摸触觉设备感知物体时,需要实现视觉-力触觉同步反馈,其中图像-力触觉反馈难点在于再现更真实的纹理触感的触觉渲染过程。本文提出了一种基于图像局部纹理特征的静电力触觉渲染模型,实现了更加清晰、触感真实的图像纹理的静电力触觉反馈。方法 首先,采用局部傅里叶变换方法强化局部纹理特征,提取傅里叶变换系数分离出表征形状和局部纹理、边缘的频域分量。其次,对局部纹理特征进行力触觉渲染,建立局部纹理特征与驱动信号的映射模型,采用比例模型将局部纹理特征值转化为同等级的静电力表达。最后,根据静电力与驱动信号的心理学模型,由局部纹理特征控制不同驱动信号的输出产生静电力触觉。结果 进行纹理触觉对比感知实验验证算法有效性,62.5%的实验参与者偏爱基于图像局部纹理的触觉渲染算法反馈的纹理触感,本文算法可以模拟多种图像的纹理、边缘的触感。结论 算法在频域分离图像局部纹理、边缘和形状特征,建立纹理-力触觉渲染模型,针对大多数图片可以有效地增强纹理触感,提升触觉再现交互技术的沉浸感。     

面向视频感知的静电力触觉渲染方法

针对视觉障碍的人获取视频等数字媒体信息受限的问题, 为扩展视频等数字媒体信息的触觉感知通道,提出一种面向视频感知的静电力触觉渲染方法。首先,采用基于像素点的视频帧处理算法,根据手指触摸位置获取当前视频帧的目标像素点,然后将目标像素点彩色信息从RGB模型转换为HSI模型,利用像素点色调分量来映射静电力激励信号频率参量,结合像素点亮度和饱和度分量来映射静电力激励信号幅度参量,合成静电力触觉激励信号,实现对实时视频的触觉渲染和感知。最后,设计动态色彩感知实验和亮度辨识感知实验,结果表明,该方法可实现对视频中物体信息的触觉感知,动态识别平均正确率达90.6%,色彩辨识平均正确率达69.4%,亮度辨识平均正确率达80.0%,所提方法能有效提取视频中的动态特征信息,增强视频触觉渲染的实时性。     

Perception-based model simplification for motion blur rendering

Motion blur effects are important to motion perception in visual arts, interactive games and animation applications. Usually, such motion blur rendering is quite time consuming, thus blocking the online/interactive use of the effects. Motivated by the human perception in relation to moving objects, this paper presents simplified geometric models that enable to speedup motion blur rendering, which has not been tracked in motion blur rendering specifically. We develop a novel algorithm to simplify models with motion-aware, to preserve the features whose characteristics are perceivable in motion. We deduce the formula to outline the level of detail simplification by the object moving velocity. Using our simplified models, methods for motion blur rendering can achieve the rendering quality as using the original models, and obtain the processing acceleration mostly. The experimental results have shown the effectiveness of our approach, more acceleration with the larger models or faster motion (e.g. for the dragon model with over a million facets, the motion-blur rendering via hierarchical stochastic rasterization is sped up by over 27 times).     

参数曲面导矢界估计及其在曲面绘制中的应用

目的是改进参数曲面的绘制效率。采用的方法是在参数曲线导矢界的基础上，进一步提出了3次参数曲面导矢界的公式。基于这些公式，能够较好地解决了参数曲面绘制算法过程中出现的重复绘制的问题和不连续的问题，进一步提高了曲面绘制的效果和效率。     

A Surface Rendering Approach in 3D Rectilinear Datafield

This paper presents an approach for surface rendering in 3D rectilinear datafield.The approach will first detect the border of the given object in the field by underlying function fitting and the second gradient derivative calculating.On marking the border cells,they will be rendered in polygons to fit the surface of the object.Te implementation,as well as some experiments,is given in the paper.     

A study of tile design for tactile guide pathways

Tactile guide paths can assist blind people to follow a particular route by using their shod feet to detect and distinguish raised patterns. Two kinds of tile are used to form a tactile guide path, pathway tiles with raised strip patterns are used to indicate the direction of travel to be taken and dome tiles with raised dot patterns are used to indicate a potential hazard or a junction. However, the contrast between these two tiles is not very great, so the users may not detect a junction or hazard. The experiment reported here compared existing guide paths with a possible new design, in which, the stimulation from pathway tiles was altered to provide a higher contrast with dome tiles. Twenty-three blind subjects participated in this study. They negotiated an existing guide path and a new design guide path. Each path was 30.3 m long and containing 10 junctions. Performance and responses of the subjects were used to evaluate the paths. The results showed that junction discrimination accuracy and time for the new design were significantly better than for the old design. The subjects also said that that new design was better.

Relevance to industry

Improving the discriminability of the patterns on tactile guide paths may result in enhancing the mobility of blind people. They can then perhaps become more independent and employable.     

A pattern classification by dynamic tactile sense information processing

This paper describes pattern classification with an artificial tactile sense. In this method, an object's shape is determined by touching, groping and grasping it with an artificial hand with tactile sense.

A simplified experiment classifying cylinders and square pillars was performed by an artificial hand with on-off switches instead of pressure sensitive elements. Highly reliable results were obtained. In addition, results of a surface groping experiment are given.     

Autonomous tactile perception: A combined improved sensing and Bayesian nonparametric approach

In recent years, autonomous robots have increasingly been deployed in unknown environments and required to manipulate or categorize unknown objects. In order to cope with these unfamiliar situations, improvements must be made both in sensing technologies and in the capability to autonomously train perception models. In this paper, we explore this problem in the context of tactile surface identification and categorization. Using a highly-discriminant tactile probe based upon large bandwidth, triple axis accelerometer that is sensitive to surface texture and material properties, we demonstrate that unsupervised learning for surface identification with this tactile probe is feasible. To this end, we derived a Bayesian nonparametric approach based on Pitman–Yor processes to model power-law distributions, an extension of our previous work using Dirichlet processes Dallaire et al. (2011). When tested against a large collection of surfaces and without providing the actual number of surfaces, the tactile probe combined with our proposed approach demonstrated near-perfect recognition in many cases and achieved perfect recognition given the right conditions. We consider that our combined improvements demonstrate the feasibility of effective autonomous tactile perception systems.     

Playing vibrotactile music: A comparison between the Vibrochord and a piano keyboard

A novel vibrotactile musical input device called the Vibrochord, which is designed to deliver patterns of vibration to the skin, not to the ear, through the use of a vibrotactile display called the Emoti-Chair, is evaluated using proposed evaluation frameworks. Findings show that the mixture of frameworks used in this study provided valuable insight into the design of this novel musical device. Results obtained through the implementation of a mixture of these frameworks show that the Vibrochord facilitated an increased accuracy rate over the traditional piano keyboard, when inexperienced vibrotactile musicians tried to repeat vibrotactile patterns or “melodies”.     

A study on the subjective feeling affecting tactile satisfaction of leather in automobile: A structural equation modeling approach

Customer expectations for automotive design are increasingly rising, which plays an important role in purchasing behavior. Among them, automobile interior materials are one of the factors that have a significant influence on the overall luxuriousness and satisfaction of automobiles. One of the main affective responses to automotive interior materials is a tactile sensation, and since it is complexly constructed, systematic modeling is required. The current research proposed and tested a structural equation model (SEM) that describes hypothesized relationships among affective variables affecting tactile satisfaction such as luxury, soft, slippery, smooth, bumpy, and thick. A total of 26 samples including natural and synthetic leather using interior material in an automobile was selected as a stimulus to recruit 53 participants. All affective variables were found to affect luxuriousness that subsequently affected tactile satisfaction (path coefficient = 0.652). In particular, perceived softness was a dominant factor affecting tactile luxuriousness in leather (path coefficient = 0.305). The findings of the present study have significant implications for both theory and practice on affective responses and levels that affect tactile satisfaction in leather using automobile interior.     

混合使用细节层次与基于图像渲染技术的大面积森林实时渲染算法研究*

描述了一个新的结合细节层次算法和基于图像渲染的森林渲染系统,平衡了基于图像的渲染方法在渲染质量上的不足与几何渲染方法在效率上的缺陷。提出了一种新的基于四叉树纹理拼图的替代物渲染加速算法,有效地提升了替代物创建与渲染速度。最后,在一个实际的室外场景漫游程序中的运行结果表明了该系统可以用较小的渲染代价获得很高的渲染质量。     

移动在线实时绘制技术研究综述

移动在线实时绘制技术受移动互联网发展的驱动,为3维可视化、计算机视觉、虚拟现实、增强现实、扩展现实和元宇宙等新兴研究领域提供了核心技术的支撑。本文以在线实时绘制技术为切入点,探讨了该技术在移动端、Web端、云端和多端协同这4类平台下的发展重心和研究现状,并深度阐述了工业级在线云平台的实施方案。首先,针对移动端的在线实时绘制,分析了近年来移动端绘制硬件构架设计的优化方向;探讨了在功耗和带宽受到制约的情况下移动端如何对渲染算法进行加速,如何对高功耗的光线跟踪算法进行优化;列举了包括图形应用程序编程接口(application programming interface,API)和游戏引擎在内的移动端渲染工具。然后,针对Web端在线实时绘制,分析了Web端的3D渲染机制,梳理了以3D场景的轻量化预处理、大规模3D场景的细粒度化网络传输、3D场景的对等传输以及Web3D在线特效渲染为代表的Web端在线绘制的关键技术(尤其面向大规模3D场景),列举了国内外知名Web3D引擎并探讨了主流游戏引擎对Web3D应用的支持。再后,针对云端在线实时绘制,从应用托管、资源调度和串流这三大云平台的核心功能入手,调研了以串流应用优化技术为核心的在线云绘制现状。此后,从多端绘制任务分摊机制入手,分析了以“端云”协同和“端边云”协同为目标的在线多端协同绘制的发展。最后,以当前工业级在线云绘制平台为研究对象,分析了包括微软、英伟达、Unity、酷家乐等一线云绘制企业的在线实时云绘制平台方案,验证了移动在线绘制技术在工业界的实用性。     

A user study on tactile graphic generation methods

Methods to automatically convert graphics into tactile representations have been recently investigated, creating either raised-line or relief images. In particular, we briefly review one raised-line method where important features are emphasized. This paper focuses primarily on the effects of such emphasis and on comparing both raised-line and relief methods (produced by a Tiger Braille printer) through psychophysical experiments including discrimination, identification, and comprehension (involving 14 sighted and 6 blind subjects). Results show that raised-line pictures outperform relief images in all three tasks. Also, emphasizing important features significantly increases comprehension of tactile graphics. Raised-line images, however, disregard intensity/colour information unlike relief pictures. A technique incorporating intensity into raised-line graphics is also presented. Further experiments show the validity of this technique.     

Fast generation of spherical slicing surfaces for irregular volume rendering

An efficient algorithm for generating a set of concentric spherical slicing surfaces for volume rendering of irregular volume datasets is presented. Our original algorithm, which approximates volume rendering by accumulating concentric spherical slicing surfaces from back to front, generates these surfaces by means of a conventional isosurface generation algorithm. However, this causes a performance bottleneck. To solve the problem, we propose a proliferous generation of slicing surfaces from seed cells, which are automatically determined according to the extremum points of the values of distances from a viewing point. A benchmark test shows that this approach can improve the performance significantly. In addition, we compare this algorithm with a raycasting algorithm that we proposed previously, and discuss a criterion for selecting which one to use for maximizing the performance