Design of the Fixation Mechanism for a Cable-driven Upper-limbExoskeleton Rehabilitation Robot
XU Chenyang1, ZHANG Jianbin1, CHEN Weihai2, WANG Jianhua2, FANG Zaojun3, YANG Guilin3
1. School of Mechanical Engineering & Automation, Beihang University, Beijing 100191, China; 2. School of Automation Science & Electrical Engineering, Beihang University, Beijing 100191, China; 3. Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo 315201, China
Abstract:In order to reduce the kinematic modeling error caused by the structural instability of the cable-driven parallel exoskeleton, improve the adaptability of the exoskeleton to different subjects, and increase the comfortability of the exoskeleton, a new design of fixation mechanism is proposed and applied to the CURE-7 (cable-driven upper-limb rehabilitation exoskeleton with 7-degrees-of-freedom). Firstly, a cable-driven exoskeleton rehabilitation robot with a new fixation mechanism is introduced, which has the advantages of both cable-driven device and parallel mechanism. Then the underactuated fixation module and flexible elbow joint of the fixation mechanism are designed, a kinematic model is developed for the exoskeleton, and the influences of the key parameters are studied. Finally, a prototype of the fixation mechanism is developed and installed on the exoskeleton, with which the trajectory tracking experiment and the fixation stress experiment on healthy subjects are carried out to prove the effectiveness of the fixation mechanism. Experimental results show that the average standard error of the elbow joint flexion trajectory tracking decreases by about 41%, the average standard error of shoulder joint abductor trajectory tracking decreases by about 30%, the maximum fixation stress decreases by about 23%, and the variances of stress in different positions are also greatly reduced, by using the new fixation mechanism.
[1] 杨启志, 曹电锋, 赵金海.上肢康复机器人研究现状的分析[J].机器人, 2013, 35(5):630-640. Yang Q Z, Cao D F, Zhao J H. Analysis on state of the art of upper limb rehabilitation robots[J]. Robot, 2013, 35(5): 630-640. [2] Zeiaee A, Soltani-Zarrin R, Langari R, et al.Kinematic design optimization of an eight degree-of-freedom upper-limb exoskeleton[J]. Robotica, 2019, 37(12): 2073-2086. [3] Li J F, Cao Q, Dong M J, et al.Compatibility evaluation of a 4-DOF ergonomic exoskeleton for upper limb rehabilitation [J]. Mechanism and Machine Theory, 2021, 156. DOI: 10.1016/ j.mechmachtheory.2020.104146. [4] Huang J, Tu X K, He J P.Design and evaluation of the RUPERT wearable upper extremity exoskeleton robot for clinical and in-home therapies[J]. IEEE Transactions on Systems, Man, and Cybernetics: Systems, 2016, 46(7): 926-935. [5] Cui X, Chen W H, Jin X, et al.Design of a 7-DOF cable-driven arm exoskeleton (CAREX-7) and a controller for dexterous motion training or assistance[J]. IEEE/ASME Transactions on Mechatronics, 2017, 22(1): 161-172. [6] Bai S P, Christensen S, Islam M R U.An upper-body exoskeleton with a novel shoulder mechanism for assistive applications [C]//IEEE International Conference on Advanced Intelligent Mechatronics. Piscataway, USA: IEEE, 2017: 1041-1046. [7] Cappello L, Dinh B K, Yen S C, et al.Design and preliminary characterization of a soft wearable exoskeleton for upper limb [C]//6th IEEE International Conference on Biomedical Robotics and Biomechatronics. Piscataway, USA: IEEE, 2016: 623-630. [8] Trigili E, Crea S, Moise M, et al.Design and experimental characterization of a shoulder-elbow exoskeleton with compliant joints for post-stroke rehabilitation[J]. IEEE/ASME Transactions on Mechatronics, 2019, 24(4): 1485-1496. [9] Zhang L Y, Li J F, Su P, et al.Improvement of human-machine compatibility of upper-limb rehabilitation exoskeleton using passive joints[J]. Robotics and Autonomous Systems, 2019, 112: 22-31. [10] 张雷雨, 李剑锋, 刘钧辉, 等.上肢康复外骨骼的设计与人机相容性分析[J].机械工程学报, 2018, 54(5):19-28. Zhang L Y, Li J F, Liu J H, et al. Design and human-machine compatibility analysis of Co-Exos for upper-limb rehabilitation[J]. Journal of Mechanical Engineering, 2018, 54(5): 19-28. [11] Jarrasse N, Morel G.Connecting a human limb to an exoskeleton[J]. IEEE Transactions on Robotics, 2012, 28(3): 697-709. [12] Hasegawa Y, Hasegawa T, Eguchi K.Pneumatic tubular body fixture for wearable assistive device-Analysis and design of active cuff to hold upper limb-[C]//IEEE/RSJ International Conference on Intelligent Robots and Systems. Piscataway, USA: IEEE, 2014: 2140-2145. [13] Catalano M G, Grioli G, Farnioli E, et al.Adaptive synergies for the design and control of the Pisa/ⅡT SoftHand[J]. International Journal of Robotics Research, 2014, 33(5): 768-782. [14] Xiong C H, Chen W R, Sun B Y, et al. Design and implementation of an anthropomorphic hand for replicating human grasping functions[J]. IEEE Transactions on Robotics, 2016, 32(3): 652-671. [15] Fu H, Zhang W Z.The development of a soft robot hand with pin-array structure[J]. Applied Sciences, 2019, 9(5). DOI: 10. 3390/app9051011. [16] Hirose S, Umetani Y.The development of soft gripper for the versatile robot hand[J]. Mechanism and Machine Theory, 1978, 13(3): 351-359. [17] Hiller M, Fang S Q, Mielczarek S, et al.Design, analysis and realization of tendon-based parallel manipulators[J]. Mechanism and Machine Theory, 2005, 40(4): 429-445. [18] 呼慧敏, 晁储芝, 赵朝义, 等.中国成年人人体尺寸数据相关性研究[J].人类工效学, 2014, 20(3):49-53. Hu H M, Chao C Z, Zhao C Y, et al. Correlation of human body size data in Chinese adults[J]. Chinese Journal of Ergonomics, 2014, 20(3): 49-53. [19] Zhang J B, Li X F, Liu J M, et al.Design and analysis of a compliant elbow-joint for arm rehabilitation robot[C]//13th IEEE Conference on Industrial Electronics and Applications. Piscataway, USA: IEEE, 2018: 2321-2326. [20] Chen W H, Li Z Y, Cui X, et al.Mechanical design and kinematic modeling of a cable-driven arm exoskeleton incorporating inaccurate human limb anthropomorphic parameters[J]. Sensors, 2019, 19(20). DOI: 10.3390/s19204461.