Perception of delayed stiffness
Perception of delayed stiffness
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DOI：
10.1177/0278364907082611
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发表时间：
2007-11-01
影响因子：
9.2
通讯作者：
Mussa-Ivaldi, Ferdinando A.
中科院分区：
文献类型：
--
作者：
Pressman, Assaf;Welty, Leah J.;Mussa-Ivaldi, Ferdinando A.
先进的技术最近提供了真正身临其境的虚拟环境与遥控机器人设备。为了从远处控制运动，人类的感觉运动系统必须克服延迟的影响。目前，很少有人知道的机制，延迟环境中的触觉估计。本研究的目的是探讨延迟对表面硬度感知的影响。强迫选择范例中，受试者被要求确定两个虚拟弹簧表面的操纵没有视觉反馈的基础上更硬。虚拟曲面是通过在虚拟边界内产生一个与机械手手柄的插入量成正比的弹性力而得到的。弹性力是位移的瞬时函数，在位移之后延迟30或60毫秒，或者使位移（通过卡尔曼预测器）超前50毫秒。假设为了估计刚度，大脑将所经历的相互作用力与穿透量相关联。实验结果表明，系统的位置和力之间的延迟的估计刚度的依赖性。当力滞后于穿透时，表面被认为是更硬的。相反，当力导致渗透时，表面被认为是较软的。知觉的结果进行了比较与不同的回归模型。这使得一些候选模型被丢弃。为了进一步完善的分析，进行了第二个实验，其中的延迟仅在部分的手/表面的相互作用，无论是当手移动到弹簧状的表面，或当它是移动出来it. Findings是一致的刚度估计的基础上划分的最大力的感知量的渗透。调查结果与基于最大位置或局部刚度的顺应性估计不一致，也与基于整个力/运动历史的刚度线性估计不一致。
Advanced technology has recently provided truly immersive virtual environments with teleoperated robotic devices. In order to control movements from a distance, the human sensorimotor system has to overcome the effects of delay. Currently, little is known about the mechanisms that underlie haptic estimation in delayed environments. The aim of this research is to explore the effect of a delay on perception of surfaces stiffness. A forced choice paradigm was used in which subjects were asked to identify the stiffer of two virtual springlike surfaces based on manipulation without visual feedback. Virtual surfaces were obtained by generating an elastic force proportional to the penetration of the handle of a manipulandum inside a virtual boundary. The elastic force was either an instantaneous function of the displacement, delayed at 30 or 60 milliseconds after the displacement or led the displacement (by means of Kalman predictor) by 50 milliseconds. It was assumed that, to estimate stiffness, the brain relates the experienced interaction forces with the amount of penetration. The results of the experiment indicate a systematic dependence of the estimated stiffness upon the delay between position and force. When the force lagged the penetration, surfaces were perceived as stiffer. Conversely, when the force led the penetration, surfaces were perceived as softer. The perceptual findings were compared with different regression models. This allowed some candidate models to be discarded. To further refine the analysis, a second experiment was carried out in which the delay was introduced only during part of the hand/surface interaction, either while the hand was moving into the spring-like surface or when it was moving out of it. Findings are consistent with stiffness estimates based on dividing the maximum force by the perceived amount of penetration. Findings are not consistent with an estimate of compliance based on the maximum position or local stiffness on the way out nor with linear estimates of stiffness based on the entire force/motion history.