虚拟现实中手重映射的偏移检测阈值研究

针对虚拟现实交互（virtual reality interaction，VRI）中环境限制导致使用手的操作效率较低的问题，提出了虚拟现实中手重映射的固定偏移检测阈值估计方法以提高使用手的操作效率，该方法从人的心理感知出发，引入心理测量函数计算出偏移检测阈值从而提升交互体验。首先，根据双选择强制选择（two alternative forced choice，2AFC）理论设计实验，记录被试者使用不同偏移的虚拟手完成目标抓取任务过程中的感觉差异作为评价标准，同时记录被试者完成任务的时间，根据心理测量函数（Quickpsy）对感觉差异进行计算，估计重映射交互的检测阈值；通过协方差确定虚拟手偏移量超过阈值后的方向、幅度和轴向及其相互作用是影响触碰任务性能的显著因素，若在阈值范围内，上述因素就不再影响任务性能；最后，以某VR（virtual reality，虚拟现实）医院物资智能配送系统为例验证所提方法的可行性。研究结果表明，适当的偏移缩短了用户完成触碰任务的时间，能够在提升交互效率的同时降低传统偏移量计算方法对VR的交互保真度的影响。

Research on offset detection thresholds of hand remapping in virtual reality

In order to solve the problem of low operating efficiency caused by environmental constraints in virtual reality interaction(virtual reality interaction, VRI), this paper proposed a fixed offset detection threshold estimation method based on hand remapping in virtual reality to improve the operating efficiency of using hands. This method started from people''s psychological perception and introduced a psychometric function to calculate the offset detection threshold to improve the interactive experience. Specifically, it first designed an experiment according to the two alternative forced choice(2AFC) theory, and recorded the differences of the subjects'' sensations in the process of completing the target grasping task using different offset virtual hands as the evaluation criteria, while recorded the time that the subjects completed the task. According to the psychometric function(Quickpsy) it calculated the sensory difference, and estimated the detection threshold of the remapping interaction. Then, it used the covariance to determine the significant factors affecting the performance of the touch task, and judged the thresholds of the direction, amplitude, axial direction and their interaction, if within the threshold range, these factors no longer affected the performance of the task. Finally, this paper demonstrated the feasibility of the proposed method through a VR(virtual reality) hospital material intelligent distribution system. The research results show that the appropriate offset shortens the time that the user completes the touch task. It improves the interaction efficiency while reduces the impact of the traditional offset calculation method on the VR interaction fidelity.