Zhang Ruisi, J Schwehr Trevor, J Abbott Jake
IEEE Trans Haptics. 2020 Jan-Mar;13(1):102-108. doi: 10.1109/TOH.2020.2966483. Epub 2020 Jan 13.
The human hand detects high-frequency vibrations in all directions but cannot distinguish the direction, which suggests a multi-dimensional vibrotactile stimulus is haptically equivalent to some one-dimensional (1D) stimulus. In this article, we explore how a 6D vibrotactile stimulus rendered at the haptic interaction point (HIP) of a kinesthetic haptic interface, with the stylus held in a precision pen-hold grasp, is mapped to an equivalent 1D stimulus normalized by the detection threshold. We gather a large human-subjects data set in which we determine detection thresholds for 45 distinct combinations of three orthogonal forces and three orthogonal torques rendered at the HIP, at a single frequency of 108 Hz corresponding to the peak sensitivity in our prior study. Using this data set, we find a general quadratic weighting function to predict the 1D normalized stimulus for a given 6D vibrotactile stimulus. We find that including just seven (out of a possible 21) independent parameters in the symmetric weighting matrix is sufficient to capture the non-obvious coupling between forces and torques rendered at the HIP for dimensional reduction from 6D to 1D.
人手能检测各个方向的高频振动，但无法区分方向，这表明多维振动触觉刺激在触觉上等同于某种一维（1D）刺激。在本文中，我们探究了在运动触觉接口的触觉交互点（HIP）呈现的六维振动触觉刺激是如何映射为经检测阈值归一化的等效一维刺激的，其中触控笔以精确的握笔法握持。我们收集了一个大型人体受试者数据集，在该数据集中，我们确定了在HIP处呈现的三个正交力和三个正交扭矩的45种不同组合的检测阈值，频率为108Hz，这与我们之前研究中的峰值灵敏度相对应。利用该数据集，我们找到了一个通用的二次加权函数，以预测给定六维振动触觉刺激的一维归一化刺激。我们发现，在对称加权矩阵中仅包含七个（可能的21个）独立参数，就足以捕捉在HIP处呈现的力和扭矩之间的非明显耦合，从而实现从六维到一维的降维。
