SUMMARYRendering of rigid objects with high stiffness while guaranteeing system stability remains a major and challenging issue in haptics. Being a part of the haptic system, the behavior of human operators, represented as the mechanical impedance of arm, has an inevitable influence on system performance. This paper first verified that the human arm impedance can unconsciously be modified through imposing background forces and resist unstable motions arising from external disturbance forces. Then, a reliable impedance tuning (IT) method for improving the stability and performance of haptic systems is proposed, which tunes human arm impedance by superimposing a position-based background force over the traditional haptic workspace. Moreover, an adaptive IT algorithm, adjusting the maximum background force based on the velocity of the human arm, is proposed to achieve a reasonable trade-off between system stability and transparency. Based on a three-degrees-of-freedom haptic device, maximum achievable stiffness and transparency grading experiments are carried out with 12 subjects, which verify the efficacy and advantage of the proposed method.

中文翻译：

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一种提高触觉渲染稳定性的人体手臂机械阻抗调整方法

摘要在保证系统稳定性的同时以高刚度渲染刚性物体仍然是触觉中的主要且具有挑战性的问题。作为触觉系统的一部分，人类操作者的行为，以手臂的机械阻抗为代表，对系统性能有着不可避免的影响。本文首先验证了人体手臂阻抗可以通过施加背景力无意识地改变，并抵抗外部干扰力引起的不稳定运动。然后，提出了一种提高触觉系统稳定性和性能的可靠阻抗调整 (IT) 方法，该方法通过在传统触觉工作空间上叠加基于位置的背景力来调整人体手臂阻抗。此外，自适应 IT 算法，根据人手臂的速度调整最大背景力，提出来实现系统稳定性和透明度之间的合理权衡。基于三自由度触觉装置，对 12 名受试者进行了最大可实现刚度和透明度分级实验，验证了该方法的有效性和优势。