J4 ›› 2015, Vol. 12 ›› Issue (3): 372-381.doi: 10.1016/S1672-6529(14)60129-3

• 论文 • 上一篇    下一篇

Compound Pendulum Modeling and Resonant Frequency Analysis of the Lower Limbs for the Wearer and Exoskeleton

Yunjie Miao, Feng Gao, Dalei Pan   

  1. State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China
  • 收稿日期:2014-10-03 修回日期:2015-06-02 出版日期:2015-09-30 发布日期:2015-07-10
  • 通讯作者: Yunjie Miao E-mail:yjmiao@foxmail.com
  • 作者简介:Yunjie Miao, Feng Gao, Dalei Pan

Compound Pendulum Modeling and Resonant Frequency Analysis of the Lower Limbs for the Wearer and Exoskeleton

Yunjie Miao, Feng Gao, Dalei Pan   

  1. State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, China
  • Received:2014-10-03 Revised:2015-06-02 Online:2015-09-30 Published:2015-07-10
  • Contact: Yunjie Miao E-mail:yjmiao@foxmail.com
  • About author:Yunjie Miao, Feng Gao, Dalei Pan

摘要:

An innovative lower extremity exoskeleton with hybrid leg structures is proposed in this paper. The compound pendulum model is applied to analyze the swing motion during walking for the wearer and the exoskeleton respectively. The expression of the resonant period for the human lower limb is obtained and the optimum stride frequency, at which the energy expenditure for walking is the least, coincides with the stride frequency of strolling well. As for the exoskeleton, the relationship between the inertial parameters and the resonant period of the hybrid leg is established. To minimize the walking energy cost for the exo-skeleton, the inertial parameter design must guarantee that the resonant period of the hybrid leg coincides with the actual stride period of the wearer. The resonant period of the hybrid leg is also influenced by the scissor angle which determines the distance between the hip and the ankle of the lower extremity exoskeleton (SJTU-EX) and can be adjusted to match different stride frequencies of various motions by the proper scissor angle planning.

关键词: compound pendulum, exoskeleton, inertial parameter, stride frequency

Abstract:

An innovative lower extremity exoskeleton with hybrid leg structures is proposed in this paper. The compound pendulum model is applied to analyze the swing motion during walking for the wearer and the exoskeleton respectively. The expression of the resonant period for the human lower limb is obtained and the optimum stride frequency, at which the energy expenditure for walking is the least, coincides with the stride frequency of strolling well. As for the exoskeleton, the relationship between the inertial parameters and the resonant period of the hybrid leg is established. To minimize the walking energy cost for the exo-skeleton, the inertial parameter design must guarantee that the resonant period of the hybrid leg coincides with the actual stride period of the wearer. The resonant period of the hybrid leg is also influenced by the scissor angle which determines the distance between the hip and the ankle of the lower extremity exoskeleton (SJTU-EX) and can be adjusted to match different stride frequencies of various motions by the proper scissor angle planning.

Key words: compound pendulum, exoskeleton, inertial parameter, stride frequency