水中ロボットアームを用いた水泳時の四肢に働く非定常流体力の解明 : 水中ロボットアームの開発と流体力測定実験(流体工学,流体機械)

Abstract

The objective of this study was to clarify the unsteady characteristics of the fluid force acting on limbs during swimming. For this objective, an underwater robot arm was developed in this paper. The robot arm has five degrees-of-freedom in order to perform the various complicated limb motions during swimming. In addition, by changing the hand model into the foot one, the robot also can perform the lower limb motions. The joint torques and the resultant thrust can be measured by the force sensors attached to the robot. In a circulating water tank, an experiment to measure the fluid force was conducted for four swimming strokes of the upper and lower limbs. From the experiment, it was found that even the slight difference of the fluid forces between slightly different swimming motions can be quantified by the developed experimental system. In addition, it was suggested that 'nipping' the water by both lower limbs during the kick of the breaststroke almost does not affect the thrust generation. The developed experimental system with the robot arm is useful not only for measuring the unsteady fluid force, but also for the flow visualization in the future studies.