Propelling forces in swimmable humanoid robot

A prototype of a humanoid robot which can swim butterfly strokes has been constructed for use in place of artificial legs in water. In accordance with the determined robot control functions, the propelling speed, defined by the distance per stroke, was measured to be 0.25 meter/stroke. Based on the above experiments, the hardware of the swimmable humanoid robot was constructed using three stepping motors, electronic circuits, and a microprocessor. Mathematica was used to control the processor. The propelling force of the arms is almost the same as that of the legs, and the propelling force of the legs is averaged during one cycle of motion. However, the propelling force of the arm drastically varies during one cycle of motion,