IEEE Trans Haptics. 2021 Jul-Sep;14(3):551-563. doi: 10.1109/TOH.2021.3060108. Epub 2021 Sep 9.
When a finger touches an ultrasonic vibrating plate, a non-sinusoidal contact force is produced. This force is called acoustic finger force. In a setup where closed-loop control is performed on the vibration amplitude, a component of the acoustic finger force can be measured at the fundamental vibration frequency of the plate. This calculation is obtained from the measurement of the variation of the controller voltage between the no-load case and when a finger is present. This calculation is made for a group of twelve participants. From these results a PCA (Principal Component Analysis) model is created. This model permits estimation of the acoustic finger force response of a participant at any vibration amplitude, based on a one or two point measurement. Finally, a linear relation between the PCA coefficients and the friction reduction is proposed. The objective of this relation would be to ultimately provide the means to create an amplitude reference calibration based on the desired friction reduction level, and thus be able to produce a standardized tactile feedback for each user, despite the biomechanical differences in finger pad properties between subjects.
当手指触摸到超声振动板时，会产生一个非正弦的接触力。这个力被称为声手指力。在对振动幅度进行闭环控制的设置中，可以在板的基本振动频率处测量声手指力的一个分量。这个计算是通过测量控制器电压在空载情况下和手指存在时的变化来获得的。这个计算是针对一组十二名参与者进行的。根据这些结果，创建了一个 PCA（主成分分析）模型。该模型允许根据单点或两点测量，估算任何振动幅度下参与者的声手指力响应。最后，提出了 PCA 系数与摩擦减小之间的线性关系。该关系的目的是最终提供一种基于所需摩擦减小水平创建幅度参考校准的方法，从而能够为每个用户产生标准化的触觉反馈，尽管手指垫特性在不同个体之间存在生物力学差异。
