In this paper, a new haptic interaction is presented where the operator is in contact with the haptic device (HD) only when she/he is in contact with the virtual environment (VE). This is in contrast with traditional haptic systems, where the operator is always in contact with the HD, even if she/he is out of the VE. In this haptic interaction, a visual tracking system is used to track the operator’s finger. When the finger is out of the VE, the HD tracks the finger so that the stylus of the HD keeps a constant distance of about 2 cm from the finger. When the finger gets close to the VE, the stylus slows down and stops upon reaching the VE; it then waits until the operator touches the stylus and feels the VE. Some advantages of this haptic interaction include more immersivity, higher margins of stability, bigger workspace, smaller actuators and, more feasible impact simulation. The speed of the HD at the onset of contacting the VE plays a significant role in the stability of the haptic system. The lower the collision speed, the bigger the maximum stiffness of the VE will be. The stability improvement of this presented haptic interaction is compared with the traditional one for both low and medium collision speeds for several time delays. For low collision speeds, theoretical and experimental results show an increase of 72% and 40% in the maximum stiffness of the VE, respectively. Similarly, for medium collision speeds, 44% and 28% increase in the maximum stiffness of the VE are achieved for theoretical and experimental results, respectively.

在本文中，提出了一种新的触觉交互，其中，只有当操作员与虚拟环境（VE）接触时，操作员才与触觉设备（HD）接触。这与传统的触觉系统相反，在传统的触觉系统中，即使操作员不在VE范围内，操作员也始终与HD保持接触。在这种触觉交互中，视觉跟踪系统用于跟踪操作者的手指。当手指离开VE时，HD会跟踪手指，以便HD的触控笔与手指保持约2 cm的恒定距离。当手指靠近VE时，触控笔会减速并在到达VE时停止；然后等待操作者触摸触控笔并感觉到VE。这种触觉交互的一些优势包括更高的身临其境感，更高的稳定性裕度，更大的工作空间，更小的执行器以及 更可行的影响模拟。接触VE时HD的速度在触觉系统的稳定性中起着重要作用。碰撞速度越低，VE的最大刚度就越大。在多个时间延迟下，针对中低碰撞速度，将这种提出的触觉交互的稳定性改进与传统的相比。对于低碰撞速度，理论和实验结果表明，VE的最大刚度分别提高了72％和40％。同样，对于中等碰撞速度，理论和实验结果分别使VE的最大刚度提高了44％和28％。碰撞速度越低，VE的最大刚度就越大。在几个时间延迟下，针对中低碰撞速度，将这种提出的触觉交互的稳定性改进与传统的相比。对于低碰撞速度，理论和实验结果表明，VE的最大刚度分别提高了72％和40％。同样，对于中等碰撞速度，理论和实验结果分别使VE的最大刚度提高了44％和28％。碰撞速度越低，VE的最大刚度就越大。在几个时间延迟下，针对中低碰撞速度，将这种提出的触觉交互的稳定性改进与传统的相比。对于低碰撞速度，理论和实验结果表明，VE的最大刚度分别提高了72％和40％。同样，对于中等碰撞速度，理论和实验结果分别使VE的最大刚度提高了44％和28％。理论和实验结果表明，VE的最大刚度分别提高了72％和40％。同样，对于中等碰撞速度，理论和实验结果分别使VE的最大刚度提高了44％和28％。理论和实验结果表明，VE的最大刚度分别提高了72％和40％。同样，对于中等碰撞速度，理论和实验结果分别使VE的最大刚度提高了44％和28％。