Development of the upper body of an underwater humanoid robot for research of unsteady fluid forces acting on a swimmer

Abstract

The primary objective of this study was to develop a robot for research of human swimming. In order to address this objective, we developed the upper body of an underwater humanoid robot and realized the human swimming stroke. The developed humanoid robot had the same body proportions and appearance at half the size of a real human. The upper limbs were actuated by 12 motors, and one motor was installed for the waist. The motor case and gear housing were newly designed for waterproofing and space saving. Each arm had six degrees of freedom; four were for the shoulder and two were for the elbow. On the shoulder, we installed additional joints imitating human's scapular retraction to avoid singularities during the swimming stroke. We demonstrated the importance of an additional joint by realizing the crawl stroke arm motion, which is the most complicated of the four strokes.

Free Swimming of the Swimming Humanoid Robot for the Crawl Stroke

“…The defined joint motions in the simulation were converted to the joint angles of SWUMANOID through kinematic calculation [10]. Some weights and volumes were rearranged to realize the two simulation models.…”

“…In order to achieve swimming in the water by a humanoid robot, a swimming humanoid robot which can perform the motion of the crawl stroke, back stroke and butterfly stroke has been developed [10,11]. The successful swimming motion in the water was confirmed with the four supporting struts [12].…”

Development of a swimming humanoid robot as an experimental platform of human swimming

“…As the implementing method of the fluid force model, the swimming human simulation model 'SWUM' [4] was employed.…”

Muscle-tendon complex control by “Tension controlled Muscle” and “Non-linear Spring Ligament” for real world musculoskeletal body simulator Kenshiro

“…Takanishi et al have clarified the skeletal function of foot arch mechanism by developing a human-like foot arch mechanism with elasticity [3]. Nakashima et al have built a humanoid robot that can work under water and have evaluated human motion in water during swimming motion [4].…”