Measurement of propulsive forces in swimming by using a swimming humanoid robot

The objective of this study was to measure propulsive force during swimming motion by using a humanoid robot, SWUMANOID. First, the experimental setup in which the robot performed the swimming motions in a circulating water tank was constructed. Using the constructed experimental setup, the propulsive forces were measured by a force sensor. The swimming motions of the robot were filmed simultaneously. In the crawl stroke, two distinct peaks in the time history of the propulsive force were found when the left and right upper limbs generated the propulsive force. In the breaststroke, a small peak of the propulsive force which was generated by the upper limbs and a large peak which was generated by the lower limbs were found. In the butterfly stroke, two peaks about the same level which were generated by the upper limbs and lower limbs respectively were found. Since these results were consistent with the ones in previous researches, the validity of the present experimental results was confirmed.