An Ankle Exoskeleton Using a Lightweight Motor to Create High Power Assistance for Push-Off

Liu, Jiazhen1,2,3; Xiong, Caihua4; Fu, Chenglong1

2019-08

10.1115/1.4043456

Journal of Mechanisms and Robotics-Transactions of the ASME   影响因子和分区

1942-4302

1942-4310

Active exoskeletons have capacity to provide biologically equivalent levels of joint mechanical power, but high mass of actuation units may lead to uncoordinated walking and extra metabolic consumption. Active exoskeletons normally supply assistance directly during push-off and have a power burst during push-off. Thus, the requirements on power of motors are high, which is the main reason for the high mass. However, in a muscletendon system, the strategy of injecting energy slowly and releasing quickly is utilized to obtain a higher peak power than that of muscle alone. Application of this strategy of peak power amplification in exoskeleton actuation might lead to reductions of input power and device mass. This paper presents an ankle exoskeleton which can accumulate the energy injected by a motor during the swing phase and mostly the stance phase and then release it quickly during push-off. An energy storage and release system was developed using a four-bar linkage clutch. In addition, evaluation experiments on the exoskeleton were carried out. Results show that the exoskeleton could provide a high power assistance with a low power motor and reduced the requirement on motor power by 4.73 times. Besides, when walking with the exoskeleton, the ankle peak power was reduced by 25.8% compared to the normal condition. The strategy which imitates the working pattern of the muscle-tendon system leads to a lightweight and effective exoskeleton actuation, and it also supplies ideas for the designs of lightweight actuators that work discontinuously in other conditions.

SCI ; EI

英语

第一 ; 通讯

Guangdong Innovative and Entrepreneurial Research Team Program[2016ZT06G587]

Engineering ; Robotics

Engineering, Mechanical ; Robotics

WOS:000473023700002

ASME

20192106961548

Muscle ; Tendons

Biological Materials and Tissue Engineering:461.2

Web of Science

1.Southern Univ Sci & Technol, Dept Mech & Energy Engn, Shenzhen 518055, Peoples R China
2.Naval Logist Acad, Tianjin 300450, Peoples R China
3.Tsinghua Univ, Dept Mech Engn, Beijing 100084, Peoples R China
4.Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Wuhan 430074, Hubei, Peoples R China

Liu, Jiazhen,Xiong, Caihua,Fu, Chenglong. An Ankle Exoskeleton Using a Lightweight Motor to Create High Power Assistance for Push-Off[J]. Journal of Mechanisms and Robotics-Transactions of the ASME,2019,11(4).

Liu, Jiazhen,Xiong, Caihua,&Fu, Chenglong.(2019).An Ankle Exoskeleton Using a Lightweight Motor to Create High Power Assistance for Push-Off.Journal of Mechanisms and Robotics-Transactions of the ASME,11(4).

Liu, Jiazhen,et al."An Ankle Exoskeleton Using a Lightweight Motor to Create High Power Assistance for Push-Off".Journal of Mechanisms and Robotics-Transactions of the ASME 11.4(2019).