Most studies of grip force control focus on the manipulation of rigid objects. However, in virtual and teleoperation applications, objects are often elastic in the pinch degree-of-freedom, and are manipulated using a handle that presents haptic feedback to the user. When designing controllers for haptic grippers, it is crucial to understand how grip force is controlled when manipulating rigid and deformable objects. Here, we used a virtual teleoperation setup with a haptic gripper interface to investigate grip force control in virtual environments. Ten participants lifted virtual objects and performed vertical, cyclic motions using a haptic gripper. We manipulated the control signal to the virtual interface, the haptic properties of the gripper, and the visual properties of the virtual objects to test their effect on the grip force control. We found that participants modulated their grip force as a function of the anticipated load force in all of the experimental conditions. The control signal and properties of the haptic gripper, but not the visual properties of the objects, affected the baseline and the extent of the grip force modulation. These results can provide design guidelines for haptic grippers that elicit natural grasping in virtual and bilateral teleoperation applications.

中文翻译：

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通过触觉夹持器与可变形和刚性物体进行虚拟交互期间的夹持力控制

大多数对握力控制的研究都集中在操纵刚性物体上。然而，在虚拟和远程操作应用程序中，对象通常在捏合自由度方面具有弹性，并且使用向用户呈现触觉反馈的手柄进行操作。在为触觉抓手设计控制器时，了解在操纵刚性和可变形物体时如何控制抓握力至关重要。在这里，我们使用带有触觉抓手界面的虚拟遥操作设置来研究虚拟环境中的握力控制。十名参与者举起虚拟物体并使用触觉抓手执行垂直循环运动。我们操纵虚拟界面的控制信号、夹具的触觉特性和虚拟物体的视觉特性来测试它们对握力控制的影响。我们发现参与者在所有实验条件下将他们的握力作为预期负载力的函数进行调节。触觉抓手的控制信号和属性，而不是物体的视觉属性，影响了基线和抓握力调制的程度。这些结果可以为在虚拟和双边遥操作应用中引发自然抓取的触觉抓手提供设计指南。