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1.
网络对盲人有积极的意义.近年来,力/触觉作为一种辅助盲人访问Internet的技术得到了研究.介绍了力/触觉技术的基本原理,通过与读屏技术比较,探索其优势和发展的必要性.按触觉和力反馈分类,总结了辅助盲人上网力/触觉技术的研究现状及特点,提出现阶段存在的问题,并展望该领域的发展前景.  相似文献   

2.
基于力敏导电橡胶材料,设计了一种四电极对称结构的三维力柔性触觉传感器.利用有限元分析软件ANSYS,结合橡胶材料的Mooney-Rivlin本构模型,对传感器加载垂直力和剪切力进行有限元分析,得到传感器在三维力作用下的应力应变分布状态,并进行了实验验证,结果表明了传感器结构设计和数学模型构建的合理性.通过对传感器传力的触头材料和形状进行有限元分析,表明触头选择硬度相对较大的材料,制成长椭球状半径(a=1.5b),可以优化传感器的性能,为用于检测三维力的柔性触觉传感器的实际应用提供了依据.  相似文献   

3.
针对如何提高虚拟触觉再现的精度与实时性问题,提出了一种新颖的基于物理意义的平行菱形链连接触觉变形模型.该模型中各个链结构单元中菱形的长度等比例变化,因而计算量小;改变链结构单元中菱形的长度和夹角就可方便对不同的柔性体进行建模,系统中各个链结构单元的相对位移的叠加对外等效为物体表面的变形,与之相连的弹簧弹性力的合力等效为物体表面的接触力.利用手控器对柔性体的接触变形和实时虚拟触觉反馈进行了仿真.实验表明所提出的方法适用于柔性体的触觉反馈计算,能够满足精细作业对虚拟现实系统的要求.  相似文献   

4.
由于缺乏实时的传感器信息反馈,导致传统的基于原子力显微镜的纳米操作盲目,操作效率和成功率都非常低.为了克服这一问题,设计和实现了一种具有实时视觉和三维触觉反馈的纳米操作系统.当利用该系统进行纳米操作时,操作者不但可以实时感受到探针与被操作物体间的相互作用力,还可以在3D增强现实图像界面中观察到纳米操作场景的变化,并可以在线控制探针的三维运动.这种交互式的操作系统使得纳米操作变得容易可行.纳米刻画实验和多壁碳纳米管的推动实验验证了该系统的有效性和高效率.  相似文献   

5.
黄英  陆伟  赵小文  赵兴 《计量学报》2012,33(6):523-527
分析了碳纤维/硅橡胶导电复合材料的拉伸、弯曲及压敏特性,基于上述特性设计了一种新型的应用于机器人关节等活动部位的柔性压力触觉传感器。通过解耦算法解决了拉伸、弯曲引起的干扰问题,构建了求解接触压力的数学模型。实验结果表明,该柔性触觉传感器具有拉伸和弯曲性,并消除了拉伸和弯曲对接触压力的检测的干扰,可应用于机器人关节。  相似文献   

6.
以通用有效介质理论为基础,得出柔性触觉传感器用温度敏感导电橡胶的电阻-温度计算模型。采用炭黑-硅橡胶导电复合体系(导电/炭黑橡胶)作为实验材料,对该模型进行了实验验证。结果表明,在填料分布均匀、体积分数接近渗流体积分数等边界条件下,电阻-温度计算模型与实验结果吻合,表现出一致的"电阻-正温度系数"(PTCR)变化规律。在温度场的作用下,基体的体积膨胀而导致炭黑浓度被稀释的过程对PTCR效应存在重要影响;基体的体积膨胀导致材料形状的改变对PTCR效应无显著影响。  相似文献   

7.
一类具有非线性饱和传染力的传染病模型   总被引:18,自引:1,他引:17  
讨论了一类具有非线性饱和传染力的SIS流行病模型,确定了各类平衡点存在的阈值条件,利用线性化和李亚谱诺夫-拉塞尔的方法,得到了各类平衡点全局稳定性的条件。  相似文献   

8.
分析了不同填料用量及种类对导电橡胶外场特性(压力、温度)的影响。结果表明,导电网络密度的增大与损伤使得导电橡胶呈现电阻-负压力系数(NPC)和电阻-正压力系数(PPC),热膨胀和热扰动共同作用使得导电橡胶呈现电阻-负温度系数(NTC)和电阻-正温度系数(PTC)。热膨胀起主导表现出PTC效应,热扰动起主导则表现出NTC效应。填料用量与种类对于导电橡胶的外场特性影响显著,炭黑(8%)(质量分数,下同)和石墨(5.2%)并用填充导电橡胶,同时消除了PPC和NTC效应,可用于制作压力/温度复合柔性触觉传感器用敏感材料。  相似文献   

9.
提出了一种用于微结构几何量测量的MEMS三维微触觉式传感器在横向负载下的力学模型,用于指导传感器的设计和优化.对传感器的整体刚度、敏感梁的应力分布、检测灵敏度及线性灵敏度进行了计算.利用ANSYS有限元仿真方法模拟了传感器的应力分布,分布曲线与理论曲线的偏差小于3.87%,最大应力的仿真和理论偏差小于3.63%.通过一个已完成传感器的性能标定,灵敏度的实验和理论误差为7.79%,实验值线性误差为0.2%.  相似文献   

10.
研究了具有柔性前臂的两连杆柔性机器人的混合力/位置控制问题。首先,利用奇异值分解法对所给出的受限柔性机器人模型进行分解,再利用伪逆的概念引入一个新的降阶坐标使各子系统降价,并分别对各子系统进行力控制器和位置控制器的设计。为了获得对拟静态假设的鲁棒补偿,对位置控制器采用变结构控制并进行了理论论明。最后,通过仿真进一步验证了本方案高精度性和强鲁棒性。  相似文献   

11.
复杂场景下的变形目标跟踪   总被引:1,自引:0,他引:1  
提出一种新的针对目标变形的模板匹配跟踪方法。对于跟踪序列图像中的目标,采用均值平移方法对原图像进行滤波平滑后提取边缘;定义一种点到邻域的广义距离测度,增强了匹配的容错性,与计算 Hausdorff 距离相比计算量大为减少;采用边缘相似点的距离均值和方差作为匹配的相似测度和置信准则,进一步降低了匹配的误差;提出在 8 邻域内基于马尔可夫模型的启发式规则修正模板策略,阻止跟踪点漂移。实验结果表明,该方法能以高达 98%的正确匹配率对复杂场景序列图像中的运动目标进行稳定跟踪。  相似文献   

12.
A new quadrilateral 4‐node element for shear deformable plates is developed based on the hybrid stress formulation. The element is designed to be simple, stable, free of locking and to pass all the patch tests. To this purpose, special attention is devoted to select displacement and stress approximations. The standard displacement interpolation is enhanced by linking the transverse displacement to the nodal rotations and an appropriate stress approximation is rationally derived. In particular, the assumed stress approximation is equilibrated within each element, co‐ordinate invariant and ruled by the minimum number of parameters. Excellent element performance is demonstrated by a wide experimental evaluation. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

13.
基于SPM的超媒体人机接口   总被引:1,自引:0,他引:1  
当利用扫描隧道显微镜(SPM)作为一种纳米操作工具时,由于其缺乏实时的传感器信息反馈,而大大阻碍了它的广泛应用.利用超媒体人机交互接口可以解决这个问题.在纳米操作过程中,超媒体接口不但可以为操作者提供可实时更新的仿真操作场景,还可以通过力反馈手柄让操作者实时地感受到探针受到的三维纳米操作力.除此之外,操作者还可以通过该手柄直接控制探针的三维运动.最后在聚碳酸酯上进行了超媒体人机接口的纳米刻画实验.实验结果验证了该系统的有效性和效率.  相似文献   

14.
In this paper, a simple model is proposed for chaos studies. The model consists of a state, time delay and a nonlinear element. It can be described as an autonomous continuous-time difference-differential equation with only one variable. The rich behaviour of the system is numerically illustrated.  相似文献   

15.
The haptic playback system is important to the training of sensorimotor skills. With the intent for training medical students in surgery, a real-time incision training system with haptic playback is developed in this paper. This system has three modes. Mode I sets the standard cutting trajectory of the incision operation carried out by an expert. Mode II allows students to track the trajectory by haptic guidance to feel the expert's motion. Mode III lets students experience the force feeling of the expert by following the trajectory via the visual cue. To accomplish these tasks, an adjustment proportional-derivative (PD) controller and a cutting model with real-time haptic feedback are devised. The cutting model adopts the mesh adaption method for real-time simulations of progressive cutting operations. These devised methods have been configured with a haptic device PHANToM Desktop to validate the capability of the proposed training system.  相似文献   

16.
In the present work, for the first time, an analytical approach based on upper-bound theorem is proposed to analyze the simple shear extrusion process. In this regard new die parameter named maximum inclination angle is introduced. By this model, the power dissipated on all frictional and velocity discontinuity surfaces is determined and the total power is optimized for two types of die, fixed and movable inlet channel die. To check the validation of the upper-bound model, the process is simulated by the commercial finite element code, Deform-3D. To compare the theoretical results with experiments, a fixed inlet channel die and two dies with movable inlet channel are used to determine the processing force for different cross sections. The developed model predicts that the relative extrusion pressure increases with increasing the constant friction factor; also, for a given value of the constant friction factor and the maximum distortion angle, there is an optimized maximum inclination angle which minimizes the power. Comparing the fixed inlet channel die with the movable inlet channel one, it is seen that the optimized maximum inclination angle is higher in the FIC die.  相似文献   

17.
The human spine is a biomechanical structure that allows complex motions while providing stability and protection for the spinal cord during a variety of loading conditions. In this study, finite element models of spine are developed to investigate clinical problems as well as to predict its biomechanical behaviour. This research proposes a combination of an online real-time FE simulator and an offline nonlinear FEA solver. Haptic feedback is provided in the online FE simulator to enhance the human–computer interaction of the system. Primitive results of spinal deformation can be obtained from the haptic online FE simulator. The offline FEA solver provides detailed deformation and strain/stress information based on the primary simulation results from the online FE simulator.  相似文献   

18.
The paper suggests a mathematical model of hydrodynamic influence on a multi-layer deformable coal seam, based on transient poroelastic equations with regard to nonlinear dependence on the pressure for the filtration coefficients. For numerical simulation a general problem setting is given, and the semi-discrete finite element approximations and time integration schemes for the equations of the finite element method are provided. By using an analogy between poroelasticity and thermoelasticity the transient nonlinear poroelastic problem obtained is solved as a corresponding thermoelastic problem. As example, an axisymmetrical problem with input data corresponding to a real-world experiment of a hydrofracture in a three-layer coal seam is considered. The computational results allowed to estimate the radius of the degassing zone and verify the results obtained previously for a pure filtration problem.  相似文献   

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