Analysis of Walking under Microgravity using Passive Walking Rimless Wheel
- Paper number
IAC-11,A1,6,17,x11915
- Author
Mr. Tatsuhiko Ikeda, Keio University, Japan
- Coauthor
Dr. Terumasa Narukawa, Keio University, Japan
- Coauthor
Dr. Masaki Takahashi, Keio University, Japan
- Coauthor
Dr. Shin Yamada, Japan Aerospace Exploration Agency (JAXA), Japan
- Coauthor
Dr. Hiroshi Ohshima, Japan Aerospace Exploration Agency (JAXA), Japan
- Coauthor
Prof. Meigen Liu, Keio University, Japan
- Year
2011
- Abstract
The changes in human performance under reduced gravity have been concerned since the days of Apollo Project for planning safe manned exploration missions on celestial bodies. Walking is one of the essential activities for supporting life and mission, and therefore changes in walking characteristic have been studied. To understand the effect of microgravity to gait properties experimentally on the earth, human suspension reduced gravity simulator is often used. This method unloads the human body against the gravity with the cable. By controlling the amount of force to hoist, the desired gravity can be simulated. However, using this method, the compensation force fluctuates by the horizontal and vertical movement of the subjects. This fluctuation of the compensation force must be reduced for detailed analysis. In this paper, we propose 2 structures for gravity simulator to achieve the detailed microgravity experiment: horizontal displacement follower and force controller using linear elastic actuator. Then, after verifying its effectiveness, we will analyze the change in walking characteristics under microgravity using passive bipedal robot “rimless wheel.” Horizontal displacement follower is designed to apply the unloading force vertically in any situation. This system uses ball screw to control the position of the overhead suspension device to follow the horizontal displacement of subject measured by laser sensor. Using this follower, the fluctuation of unloading force due to the horizontal displacement is reduced. Using the passive spring system, constant unloading force can be applied easily. However, when the subject starts moving, the spring will be extended or shortened, and the force will vary. To solve the problem, we used a linear elastic actuator. This system controls the spring length by moving ball screw to keep the extension constant. Using the simulator mentioned above, we analyze the effect of gravity to the walking using passive walker, planar rimless wheel. Passive walk is the mechanism that walks down the slight slope using gravitational potential energy to purvey the kinetic energy loss by collision. Rimless wheel is one of the fundamental models of bipedal passive locomotion which can be obtained by removing the rim from the wheel. Due to the fact that passive walker uses only gravity but not external inputs such as actuator, gait will solely depends on gravity. Using the rimless wheel, we will analyze the change in walking characteristics between the earth’s and lunar gravity using high speed camera and motion capturing devices.
- Abstract document
- Manuscript document
(absent)