Li Jiting, Zheng Ruoyin, Zhang Yuru, Yao Jianchu
State Key Laboratory of Virtual Reality Technology and Systems, Beihang University, Beijing 100191, China.
IEEE Int Conf Rehabil Robot. 2011;2011:5975387. doi: 10.1109/ICORR.2011.5975387.
This paper presents an interactive exoskeleton device for hand rehabilitation, iHandRehab, which aims to satisfy the essential requirements for both active and passive rehabilitation motions. iHandRehab is comprised of exoskeletons for the thumb and index finger. These exoskeletons are driven by distant actuation modules through a cable/sheath transmission mechanism. The exoskeleton for each finger has 4 degrees of freedom (DOF), providing independent control for all finger joints. The joint motion is accomplished by a parallelogram mechanism so that the joints of the device and their corresponding finger joints have the same angular displacement when they rotate. Thanks to this design, the joint angles can be measured by sensors real time and high level motion control is therefore made very simple without the need of complicated kinematics. The paper also discusses important issues when the device is used by different patients, including its adjustable joint range of motion (ROM) and adjustable range of phalanx length (ROPL). Experimentally collected data show that the achieved ROM is close to that of a healthy hand and the ROPL covers the size of a typical hand, satisfying the size need of regular hand rehabilitation. In order to evaluate the performance when it works as a haptic device in active mode, the equivalent moment of inertia (MOI) of the device is calculated. The results prove that the device has low inertia which is critical in order to obtain good backdrivability. Experimental analysis shows that the influence of friction accounts for a large portion of the driving torque and warrants future investigation.
本文介绍了一种用于手部康复的交互式外骨骼设备——iHandRehab，其旨在满足主动和被动康复运动的基本要求。iHandRehab由拇指和食指的外骨骼组成。这些外骨骼由远程驱动模块通过缆线/护套传动机构驱动。每个手指的外骨骼具有4个自由度（DOF），可为所有手指关节提供独立控制。关节运动通过平行四边形机构完成，这样当设备的关节和其相应的手指关节旋转时，它们具有相同的角位移。得益于这种设计，关节角度可由传感器实时测量，因此无需复杂的运动学，高级运动控制变得非常简单。本文还讨论了该设备被不同患者使用时的重要问题，包括其可调节的关节活动范围（ROM）和指骨长度可调节范围（ROPL）。实验收集的数据表明，实现的ROM接近健康手部的ROM，并且ROPL覆盖了典型手部的尺寸，满足了常规手部康复的尺寸需求。为了评估其在主动模式下作为触觉设备工作时的性能，计算了该设备的等效转动惯量（MOI）。结果证明该设备具有低惯性，这对于获得良好的回驱性至关重要。实验分析表明，摩擦力的影响在驱动扭矩中占很大一部分，值得未来进一步研究。
