Janko Marco, Primerano Richard, Visell Yon
IEEE Trans Haptics. 2016 Apr-Jun;9(2):221-32. doi: 10.1109/TOH.2015.2507583. Epub 2015 Dec 17.
We investigated forces felt by a bare finger in sliding contact with a textured surface, and how they depend on properties of the surface and contact interaction. Prior research has shed light on haptic texture perception. Nevertheless, how texture-produced forces depend on the properties of a touched object or the way that it is touched is less clear. To address this, we designed an apparatus to accurately measure contact forces between a sliding finger and a textured surface. We fabricated textured surfaces, and measured spatial variations in forces produced as subjects explored the surfaces with a bare finger. We analyzed variations in these force signals, and their dependence on object geometry and contact parameters. We observed a number of phenomena, including transient stick-slip behavior, nonlinearities, phase variations, and large force fluctuations, in the form of aperiodic signal components that proved difficult to model for fine surfaces. Moreover, metrics such as total harmonic distortion and normalized variance decreased as the spatial scale of the stimuli increased. The results of this study suggest that surface geometry and contact parameters are insufficient to account for force production during such interactions. Moreover, the results shed light on perceptual challenges solved by the haptic system during active touch sensing of surface texture.
我们研究了裸手指与有纹理表面滑动接触时所感受到的力，以及这些力如何取决于表面特性和接触相互作用。先前的研究已经阐明了触觉纹理感知。然而，纹理产生的力如何取决于被触摸物体的特性或触摸方式尚不清楚。为了解决这个问题，我们设计了一种仪器来精确测量滑动手指与有纹理表面之间的接触力。我们制作了有纹理的表面，并测量了受试者用裸手指探索表面时产生的力的空间变化。我们分析了这些力信号的变化及其对物体几何形状和接触参数的依赖性。我们观察到了许多现象，包括瞬态粘滑行为、非线性、相位变化和大力波动，这些现象以非周期信号分量的形式出现，事实证明对于精细表面很难进行建模。此外，随着刺激空间尺度的增加，诸如总谐波失真和归一化方差等指标会降低。这项研究的结果表明，表面几何形状和接触参数不足以解释此类相互作用过程中的力产生。此外，这些结果揭示了触觉系统在主动触摸感知表面纹理过程中所解决的感知挑战。
