Semi-passive rehabilitation robots resist and steer a patient's motion using only controllable passive force elements (e.g., controllable brakes). Contrarily, passive robots use uncontrollable passive force elements (e.g., springs), while active robots use controllable active force elements (e.g., motors). Semi-passive robots can address cost and safety limitations of active robots, but it is unclear if they have utility in rehabilitation. Here, we assessed if a semi-passive robot could provide haptic guidance to facilitate motor learning. We first performed a theoretical analysis of the robot's ability to provide haptic guidance, and then used a prototype to perform a motor learning experiment that tested if the guidance helped participants learn to trace a shape. Unlike prior studies, we minimized the confounding effects of visual feedback during motor learning. Our theoretical analysis showed that our robot produced guidance forces that were, on average, 54° from the current velocity (active devices achieve 90). Our motor learning experiment showed, for the first time, that participants who received haptic guidance during training learned to trace the shape more accurately (97.57% error to 52.69%) than those who did not receive guidance (81.83% to 78.18%). These results support the utility of semi-passive robots in rehabilitation.

中文翻译：

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在没有电机的情况下教授运动技能：一种促进学习的半被动机器人。

半被动康复机器人仅使用可控被动力元件（例如可控制动器）来抵抗和引导患者的运动。相反，被动机器人使用不可控的被动力元件（例如弹簧），而主动机器人使用可控的主动力元件（例如电机）。半被动机器人可以解决主动机器人的成本和安全限制，但尚不清楚它们是否在康复中有用。在这里，我们评估了半被动机器人是否可以提供触觉指导以促进运动学习。我们首先对机器人提供触觉指导的能力进行了理论分析，然后使用原型进行了运动学习实验，测试该指导是否有助于参与者学习追踪形状。与之前的研究不同，我们最大限度地减少了运动学习过程中视觉反馈的混杂影响。我们的理论分析表明，我们的机器人产生的引导力平均与当前速度成 54°（有源设备达到 90°）。我们的运动学习实验首次表明，在训练期间接受触觉指导的参与者比没有接受指导的参与者（81.83% 到 78.18%）学会更准确地追踪形状（错误率从 97.57% 到 52.69%）。这些结果支持半被动机器人在康复中的实用性。