柔性仿生触觉传感器系统集成设计

设计了一种轻量级的触觉传感系统,基于压敏电阻将压力信号转换为电阻变化的原理,进一步转换为电压信号进行反相滤波处理,通过低功耗蓝牙芯片CC2541读取并无线传递触觉信息.整个系统采用仿生手指结构设计,指尖覆盖与皮肤触感相近的硅胶,柔顺传递接触力.整个电路包含供电模块、电源管理模块、触觉采样处理模块和信号传递模块,集成在第二指节内.整个传感器系统集成度高,便于实际应用.     

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。     

振动触觉的量化感知与触觉文字编码设计

针对移动设备上实现触觉交互和触觉阅读文字的难题,提出一种触觉感知量化和编码模型,并设计了振动数量索引字符表和摩斯电码2种触觉文字编码方案.该模型首先对振动触觉的振动时长、间隔时长、连续振动次数进行量化设计;然后通过实验测定用户对振动量化感知的数值;再对不同的振动时长和振动次数进行编码;最后组合不同的编码来表达文字.对编码文字的用户识别率及满意度的可用性评估实验的结果表明,通过对振动触觉进行量化感知设计和编码可以有效地提高触觉阅读效率,比传统基于盲文等的编码方案具有更高的阅读效率及更好的易用性;文中模型可在移动设备上设计触觉交互界面,实现高效的触觉文字阅读系统.     

纹理触觉信息检测系统研究

本文利用PVDF(聚偏二氟乙烯)薄膜的压电效应和其独特物理性质,设计了一种高精度、高分辨率、高速响应的具有纹理触觉感知作用的传感器;然后,模拟人体感知纹理触觉信息的过程,制作了基于伺服电机的纹理触觉信息检测平台,可以实现对纹理压电信号的采集与调理;最后,对6种典型的纹理样本进行信号采集,通过试验数据证明了该系统的有效性.     

基于柔性触觉传感器的坐姿压力监测系统设计

提出了一种有效监测人体坐姿压力的系统,设计了柔性触觉传感器阵列,基于多路模拟开关CD4051、微处理器MSP430与无线发送模块实现数据的采集与传输,在上位机软件中通过低通滤波、配色与插值算法,并应用分布式压缩感知理论,形成了模拟人体坐姿压力分布的彩色图像,图像真实清晰,便于观察.实验结果表明:系统稳定性和分辨率较好,且能够实现坐姿压力分布的实时测量和显示.     

手机空间振动触觉系统的硬件设计与实现

文章针对智能手机上触觉反馈单一的问题设计了一种利用多振动片实现手机空间触觉感知的系统.使用了2×2=4个微型振动片贴在手机后壳上,当手握持手机时通过给4个不同位置的振动片施加控制信号来表达不同的触感语义.通过对6名用户的实验优化设计了振动片的相对位置、振动时长和振动时间间隔等参数.本系统可为手机提供丰富的触觉反馈样式,为后续的手机触感交互提供了基础.     

服务机器人的触觉手势识别

为了实现机器人在人机交互过程中的触觉感知,提出了一种用于服务机器人的触觉手势识别方法。首先,将电子皮肤安装在服务机器人上,通过采集15位被试者的10种手势动作信号,构建了情感手势数据集。然后,使用时空分离卷积神经网络,对被试者触摸服务机器人时做出的触摸手势进行分类。结果表明,被试内手势识别率为90.25%,跨被试手势识别率为83.44%。通过调节模型中的时空通道调节因子,在几乎不降低识别率的同时,可以大幅减少模型参数量。基于电子皮肤的触觉手势识别实验,初步认为使用时空分离卷积神经网络能够以较高的准确率和较低的计算代价实现对人的触觉手势识别,这为服务机器人通过电子皮肤与人实现情感交互提供了可能。     

触觉再现技术研究进展

针对触觉再现技术面临的数据获取难、设备真实感低、应用数量少等问题,在触觉感知机理和触觉再现范式基础上,分析了现有触觉信号采集、建模、渲染等关键环节的方法和特点,归纳了典型触觉再现设备的种类和实现原理,讨论了触觉再现技术的主要应用领域.根据触觉再现技术的研究现状,提出了构建触觉感知模型、提高触觉数据特征提取与模型处理精度、开发低功耗低成本的普适性触觉系统与多通道融合的交互应用的未来发展方向.     

基于Residual Networks的新型触觉传感器接触状态感知与识别

基于触觉信息识别不同接触状态对于人机交互的实现具有重要意义。本文提出一种基于残差网络(Residual Networks) 识别触觉传感器不同接触状态的方法。基于弹性体模板法制备了一款具有良好触觉感知能力的多孔石墨烯柔性触觉传感器。利用该触觉传感器采集了4种不同接触状态(拍打、重击、抚摸、推压)的时间序列数据,并对采集到的数据进行z-score标准化操作以及降采样处理。在此基础上,构建具有良好自适应性和泛化能力的Residual Networks模型对施加于该触觉传感器表面的4种接触状态进行分类识别,识别准确率为97.50%。实验结果表明：本文设计的多孔石墨烯柔性触觉传感器柔弹性好、灵敏度高、响应速度快,能够有效感知不同状态的接触力,Residual Networks模型可以高效地用于触觉传感器接触状态的分类识别。     

基于音波技术的时空双通道机器人触觉再现系统研究

介绍了一种基于音波播放的时空双通道机器人触觉再现系统.系统采用音波播放技术提供触觉再现所需要的电流刺激信号和空间触点选通信号.时间通道的电流刺激控制信号和空间通道的触点选通信息均由音波处理软件根据系统需要预先设计生成.计算机声卡输出的双声道音波信号分别对应于时空两个通道的控制信息.上述信号进一步处理后将提供触觉再现刺激电流并选通相应触点.该触觉再现系统能够为操作者提供温和舒服的触觉感受.     

Development of a sensor system for collecting tactile information

This paper presents the development of a sensor system for collecting tactile information. An active sensing system using the piezoelectric effect and the pyroelectric effect of a PVDF (Polyvinylidene fluoride) film is proposed. The active sensing is designed with human motions for tactile perception in mind. First, as the pretest, the distinction examination of six fabrics with different textures is carried out through human tactile perception. Next, the proposed sensor system is assembled. The sensor is composed of a PVDF film and a soft rubber. The surface of the sensor can be heated through temperature control. The sensor is attached on the tip of a robot finger driven by a piezoelectric bimorph strip and the root of the finger is mounted on a linear slider. Two kinds of active sensing are introduced. First, the heated sensor is contacted with an object and pyroelectric output signals are collected in order to obtain the information on tactile warmth. Next, the heated sensor is slid over the object and piezoelectric output signals are collected in order to obtain the information on feelings of vibration. Through the discussion about each sensing, three indexes representing features of the collected data are extracted and proposed as the sensor outputs for the evaluation of tactile sensation. The measurement using the sensor system is done on the samples used in the distinction examination. Comparison with the results shows that the sensor system extracts features on feelings of vibration and warmth.     

The tactile discrimination of complex systems

The elementary modalities of sensation such as touch and pressure may be taken as basic units of perception, and the tactile perception of more complex systems such as matter in its various states viewed as a structured combination of these units. When the system which is discriminated or perceived is not too complex, then the relationship between the external system and the internal, physiological perceiving system may be explored. It is seen in several examples that an interesting parallel exists between discriminating and discriminated (internal and external) systems.     

基于卷积神经网络的软硬触觉感知方法研究

智能机器手的应用已经遍布医疗、军工、农业及装配行业等领域.软硬作为物体的重要物理属性之一,对机器手的抓取控制物体有重大影响.在深度学习框架下,基于卷积神经网络提出了用于触觉感知的软硬物体的识别方法.使用薄膜压力传感器采集手指按压软硬物体的数据,建立训练和测试数据集,在Caffe中训练网络,以模拟触觉识别软硬物体.实验结果显示:对软硬物体的识别准确率达94.52%,表明,卷积神经网络对于识别软硬物体有比较好的分类效果.     

三维柔性触觉/热觉传感器设计与仿真

针对目前触觉传感器研究中不能兼有柔韧性、多维力测量和热觉与触觉信号混杂等难题,设计了一种柔性多功能触觉/热觉传感器。介绍了该传感器的基本结构,并基于聚偏氟乙烯（ PVDF）薄膜的特性建立了三维力并行测量的数学模型。触觉检测基于PVDF的压电效应,热觉检测基于PVDF的热释电效应。通过对触觉和热觉信号做比例减法运算,从而彻底区分触觉和热觉信号。     

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.     

Discriminability-based evaluation of transmission capability of tactile transmission systems

Tactile transmission systems deliver tactile information such as texture roughness to operators of robotic systems. Such systems are typically composed of tactile sensors that sense the physical characteristics of textures and tactile displays that present tactile stimuli to operators. One problem associated with tactile transmission systems is that when the system has a bottleneck, it is difficult to identify whether the tactile sensor, tactile display, or perceptual ability of the user is the cause because they have different performance criteria. To solve this problem, this study established an evaluation method that uses the discriminability index as an evaluation criterion. The method lets tactile sensors, displays, and human tactile perception be assessed in terms of the ability to transmit physical quantities; the same criterion is used for all three possible causes so that their abilities can be directly compared. The developed method was applied to a tactile-roughness transmission system (Okamoto et?al. 2009), and its tactile sensor was identified as the bottleneck of the system.     

Maintaining and modifying pace through tactile and multimodal feedback

Older adults are recommended to remain physically active to reduce the risk of chronic diseases and to maintain psychological well-being. At the same time, research also suggests that levels of fitness can be raised among this group. This paper describes the development and evaluation of a mobile technology, which enables older adults to monitor and modify their walking habits, with the long-term aim of sustaining appropriate levels of physical activity. An empirical study was conducted with twenty older adults to determine the feasibility of the proposed solution, with results indicating that tactile signals could be perceived while in motion and could support participants in walking at a range of paces. However, the effects were difficult to discern due to limitations of the hardware. In response, a novel low-cost prototype was developed to amplify vibrations, and effectiveness of redundant auditory information was investigated with the goal of enhancing the perception of the cues. A second study was conducted to determine the impact of multimodal feedback on walking behavior. Findings revealed that participants were able to maintain a desired level of pace more consistently when redundant auditory information was presented alongside the tactile feedback. When the visual channel is not available, these results suggest that tactile cues presented via a mobile device should be augmented with auditory feedback. Our research also suggests that mobile devices could be made more effective for alternative applications if they are designed to allow for stronger tactile feedback.     

结合无符号Laplace谱特征的触觉步态识别算法

针对单纯利用压力点分布特征进行触觉步态识别的不足,提出了一种结合无符号Laplace谱特征的动态触觉步态识别算法。利用足底压力数字化场地采集常速、快速和慢速三种情况下的触觉步态数据,生成足底压力分布图像,并根据足底解剖学的结构划分区域;以足底压力图像各区域为节点构造结构图,并采用无符号Laplace矩阵表示;通过对该矩阵进行奇异值分解（Singular Value Decomposition,SVD）获取谱特征,并结合形状特征得到触觉步态特征;选择“一对一”的支持向量机（Support Vector Machine,SVM）多分类方法,按照人在行走过程中不同的速度分别构造分类器,从而实现动态触觉步态的识别。实验结果表明该识别算法对不同速度样本数据的触觉步态识别正确率都较高。     

Electrostatic tactile display with thin film slider and its application to tactile telepresentation systems

A new electrostatic tactile display is proposed to realize compact tactile display devices that can be incorporated with virtual reality systems. The tactile display of this study consists of a thin conductive film slider with stator electrodes that excite electrostatic forces. Users of the device experience tactile texture sensations by moving the slider with their fingers. The display operates by applying two-phase cyclic voltage patterns to the electrodes. The display is incorporated into a tactile telepresentation system to realize explorations of remote surface textures with real-time tactile feedback. In the system, a PVDF tactile sensor and a DSP controller automatically generate voltage patterns to present surface texture sensations through the tactile display. A sensor, in synchronization with finger motion on the tactile display, scans a texture sample and outputs information about the sample surface. The information is processed by a DSP and fed back to the tactile display in real time. The tactile telepresentation system was evaluated in texture discrimination tests and demonstrated a 79 percent correct answer ratio. A transparent electrostatic tactile display is also reported in which the tactile display is combined with an LCD to realize a visual-tactile integrated display system.