We present RealWalk, a pair of haptic shoes for HMD-based VR, designed to create realistic sensations of ground surface deformation and texture using Magnetorheological fluid (MR fluid). RealWalk offers a novel interaction scheme through the physical interaction between the shoes and the ground surfaces while walking in VR. Each shoe consists of two MR fluid actuators, an insole pressure sensor, and a foot position tracker. The MR fluid actuators are designed in the form of multi-stacked disc structure with a long flow path to maximize the flow resistance. With changing the magnetic field intensity in MR fluid actuators based on the ground material in the virtual scene, the viscosity of MR fluid is changed accordingly. When a user steps on the ground with the shoes, the two MR fluid actuators are pressed down, creating a variety of ground material deformation such as snow, mud, and dry sand. We built an interactive VR application and compared RealWalk with vibrotactile-based haptic shoes in four different VR scenes: grass, sand, mud, and snow. We report that, compared to vibrotactile-haptic shoes, RealWalk provides higher ratings in all scenes for discrimination, realism, and satisfaction. We also report qualitative user feedback for their experiences.

中文翻译：

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用于在 VR 中行走的磁流变流体触觉鞋

我们展示了 RealWalk，这是一款适用于基于 HMD 的 VR 的触觉鞋，旨在使用磁流变液（MR 流体）创造真实的地面变形和纹理感觉。RealWalk 通过在 VR 中行走时鞋子与地面之间的物理交互，提供了一种新颖的交互方案。每双鞋均由两个 ​​MR 流体执行器、一个鞋垫压力传感器和一个足部位置跟踪器组成。MR 流体执行器采用多层叠盘结构形式设计，具有较长的流路，以最大限度地提高流阻。随着虚拟场景中基于地面材料的MR流体致动器中磁场强度的改变，MR流体的粘度也相应地改变。当用户穿着鞋子踩在地面上时，两个MR流体执行器被压下，造成各种地面材料变形，如雪、泥和干沙。我们构建了一个交互式 VR 应用程序，并在四种不同的 VR 场景中将 RealWalk 与基于振动触觉的触觉鞋进行了比较：草、沙、泥和雪。我们报告说，与振动触觉鞋相比，RealWalk 在所有场景中的辨别力、真实感和满意度都提供了更高的评分。我们还报告了用户体验的定性反馈。