Advantages of reconfigurable and variable-impedance haptic user interfaces

背景：** 触觉交互是人类理解环境并影响环境变化的最基本方式。触觉反馈为操作机器的人提供了（例如，飞机，挖掘机，或机器人，如加拿大臂或火星漫游者）与触摸物体的感觉，他们实际上没有触摸，但操纵的机器。触觉反馈允许机器的人类操作员更轻柔、安全、可靠和精确地处理物体。 * * 触觉接口（Haptic Interface，HI）通过向用户的手施加力来产生触摸的错觉。一个HI应该有一个大的工作空间。它还应该满足反向驱动性、低视在惯性和低摩擦的要求，以获得对小反射力的最佳感知，以及满足大固有刚度和力反馈能力的要求，以获得对大反射力的最佳感知。然后，HI可以为用户以高保真度重新创建柔软和僵硬的接触体验。* *由于高的力反馈能力，高的固有刚度和大的工作空间是可取的，这项研究将确保最好的两个世界通过适当的设计和控制（包括可变阻抗控制）的冗余触觉接口（RHI），它有更多的自由度比最低限度地需要执行一项任务。* 具体目标：* SA 1：使用适当设计的RHI实现尽可能多的理想HI特性，以实现更直观和有效的用户/RHI交互。我们将研究RHI的内在优势，这些优势可以通过机械设计获得，例如，更低的惯性和更大的工作空间（与非冗余HI相比）。** SA 2：利用RHI的运动冗余实现次要目标，以进一步优化其运动和动力特性。次要目标将针对进一步的可操作性增强，表观惯性最小化和力反馈能力最大化。通过联合级闭环控制获得的这些优点超过了SA 1中获得的固有优点。* SA 3：根据给定任务/用户的要求，使用RHI冗余分辨率和阻抗调制补充SA 1中的设计和SA 2中的控制。RHI的任务和用户相关的笛卡尔级可变阻抗控制和关节级冗余分辨率将进一步提高触觉交互保真度和用户的任务性能。**新颖性：** 虽然有足够的研究冗余机械手与任务环境的相互作用，很少有人注意到RHI的设计和控制。这项研究有助于创建具有增强安全性和性能的触觉交互和遥操作系统。

BACKGROUND:******Haptic interaction is the human's most basic way to understand an environment and effect change in it. Haptic feedback provides humans who operate machines (e.g., planes, excavators, or robots such as the Canadarm or Mars rovers) with a sense of touching objects they are not actually touching but are manipulating by the machines. Haptic feedback allows the human operators of machines to handle objects more gently, safely, reliably, and precisely. ******Haptic interfaces (HIs) produce the illusion of touch by applying forces to the users' hands. An HI should have a big workspace. It should also satisfy the requirements of back-drivability, low apparent inertia and low friction for the best perception of small reflected forces, and large intrinsic stiffness and force feedback capability for the best perception of large reflected forces. Then, the HI can recreate soft and stiff contact experiences for the user with high fidelity. ******OBJECTIVES:******The currently available HIs are either parallel mechanisms with higher force feedback capability, a higher intrinsic stiffness and a smaller workspace or serial mechanisms with lower force feedback capability, a lower intrinsic stiffness and a larger workspace. Since a high force feedback capability, a high intrinsic stiffness and a large workspace are desirable, this research will secure the best of both worlds by appropriate design and control (including variable-impedance control) of redundant haptic interfaces (RHIs), which have more degrees of freedom than minimally required to perform a task. ******SPECIFIC AIMS:******* SA 1: Achieve as many of the desirable HI characteristics as possible using appropriately designed RHIs for more intuitive and effective user/RHI interaction. We will investigate the intrinsic advantages of RHIs, which can be obtained through mechanical design, e.g., a lower inertia and a larger workspace (compared to non-redundant HIs).******* SA 2: Leverage the kinematic redundancy of RHIs toward a secondary objective to optimize its kinematic and dynamic characteristics further. Secondary objectives will target further manipulability enhancement, apparent inertia minimization and force feedback capability maximization. Such advantages obtained via joint-level closed-loop control are over and above the intrinsic advantages obtained in SA 1.******* SA 3: Supplement the design in SA 1 and the control in SA 2 with RHI redundancy resolution and impedance modulation based on the requirements of a given task/user. Task- and user-dependent Cartesian-level variable-impedance control and joint-level redundancy resolution of RHIs will further improve the haptic interaction fidelity and the user's task performance.******NOVELTY:******While there is ample research on redundant manipulators that interact with task environments, little attention has been paid to the design and control of RHIs. This research helps create haptic interaction and teleoperation systems with enhanced safety and performance.