Tandem Stance Avoidance Using Adaptive and Asymmetric Admittance Control for Fall Prevention.

Journal: IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society
Published Date:

Abstract

Fall prevention is one of the most important functions of walking assistance devices for user's safety. It is preferable that these devices prevent the user from being in the state where the risk of falling is high rather than helping them recovering from falling motion. During turning, when the user is in the tandem stance, a state where both legs form a line along walking direction, a support base that is surrounded by two legs becomes small, and a stability margin becomes small. This paper therefore aims to prevent the tandem stance by using nonwearable robot "intelligent cane" for the elderly or physically challenged person. Generally, the behavior of the lower limb follows the upper body turning. This paper therefore introduces a cane robot control method which constrains the behavior of user's upper body. By adjusting an admittance parameter of the robot according to the positions of a support leg, the robot resists to turn while a support leg is on the same side of the turning direction. A swing leg on the turning direction side therefore freely moves to the turning direction, while a swing leg on the opposite direction side of turning hardly move to the turning direction.

Authors

  • Shotaro Nakagawa
  • Yasuhisa Hasegawa
  • Toshio Fukuda
  • Izumi Kondo
  • Masanori Tanimoto
  • Pei Di
  • Jian Huang
    Center for Informational Biology, University of Electronic Science and Technology of China, No. 2006, Xiyuan Ave, West Hi-Tech Zone, Chengdu 611731, P. R. China.
  • Qiang Huang
    Department of Orthopedics, West China Hospital, Sichuan University, Chengdu Sichuan, 610041, P.R.China.