Abstract
The butterfly stroke of man's swimming imitates a dolphin, which is excellent in swimming. Therefore, the authors created a swimming humanoid robot which swam like a dolphin. This swimming robot was able to swim in various ways and the operation sequence of servomotors for better swimming was acquired by the particle swarm optimization (PSO). Since fishes can swim skillfully in spite of their simple structure, the velocity distribution of water flow around a real swimming fish has been measured by PIV and analyzed by CFD in order to create new fish robots which can swim like a living fish. A flexible fish robot with 6 motor-string actuators was created and their operation sequence was semi-optimized by the genetic algorithm (GA). Moreover, a wireless-controlled small fish robot with two servomotors was created. It has been shown by PIV measurement that this fish robot with a suitable motor operation sequence generates the reverse Karman vortex street as a real swimming fish does.
