IEEE Trans Haptics. 2020 Jul-Sep;13(3):493-503. doi: 10.1109/TOH.2020.2981307. Epub 2020 Mar 18.
Nowadays, tactile surfaces, such as smartphones, provide haptic feedback to signify that a task has been performed correctly or more generally to enrich the interaction. However, this haptic feedback induces vibrations in the surface that propagate to the whole surface, reverberate and attenuate, thus making multi-finger interaction, with different feedbacks, difficult. Recently, the Inverse Filter Method has been proposed to control the propagation of these vibrations, and thus enable to product localized multitouch on a glass surface. This way, a user can put several fingers on a tactile surface and yet feel stimuli independently on his/her different fingers. This article continues this work and demonstrates that a localized multitouch haptic feedback can be delivered in real time using a capacitive screen. To achieve this, this article presents the two necessary steps: a calibration step and an interpolation calculation in order to save calculation and learning time. Furthermore, the paper describes the performance of the device through a study on the behaviour of the screen subjected to the Inverse Filter Method, indicating the movement of the whole screen and the voltage requirement for any haptic feedback.
如今，触觉表面（如智能手机）提供触觉反馈，以表示任务已正确完成，或者更普遍地丰富交互。然而，这种触觉反馈会在表面上产生振动，这些振动会传播到整个表面，产生回声并衰减，从而使得多手指交互（具有不同的反馈）变得困难。最近，已经提出了逆滤波器方法来控制这些振动的传播，从而能够在玻璃表面上产生局部多点触摸。这样，用户可以将几个手指放在触觉表面上，并且仍然可以独立地感觉到他/她的不同手指上的刺激。本文继续这项工作，并证明可以使用电容屏实时提供局部多点触摸触觉反馈。为了实现这一点，本文提出了两个必要的步骤：校准步骤和插值计算，以节省计算和学习时间。此外，本文还通过研究逆滤波器方法对屏幕行为的影响，描述了该设备的性能，说明了整个屏幕的运动以及任何触觉反馈所需的电压。
