Soft interaction between body weight support system and human using impedance control based on fractional calculus

Yo Kobayashi, Takao Watanabe, Masatoshi Seki, Takeshi Ando, Masakatsu G. Fujie

Research output: Contribution to journalArticle

3 Citations (Scopus)


In recent years, research and development have been conducted on robots designed to assist people with disabilities in daily activities. There is a great demand for control technology for realizing flexible contact and cooperative behavior. We here report a novel impedance control method based on a fractional calculation inspired by the viscoelastic properties of biomaterials such as muscle. This paper presents an evaluation of this concept by simulation and by experiment using a robotic system for body weight support. The experimental results demonstrated that the fractional impedance controller has superior contact force absorption performance compared with a conventional controller, especially for high-stiffness objects and high-velocity movement. This fractional impedance controller may be useful especially for the purpose of flexible contact for assistive and rehabilitation robots for people.

Original languageEnglish
Pages (from-to)1253-1269
Number of pages17
JournalAdvanced Robotics
Issue number11-12
Publication statusPublished - 2012 Jul 1



  • body weight support
  • flexible contact
  • fractional calculus
  • impedance control
  • viscoelasticity

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Human-Computer Interaction
  • Computer Science Applications
  • Hardware and Architecture
  • Software

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