抄録
A water surface running machine is a machine that runs along the water surface like a basilisk lizard. The machine supports its body weight by slapping its feet on the water surface and stroking them into the water. This report presents the design of its leg mechanism driven by pneumatic actuators. To realize the water surface running machine, it is required to generate large upward force when the machine slaps and strokes its foot into the water and minimize downward force when the machine pulls its foot out of the water by using actuators with large power/weight ratio. As such an actuator, pneumatic actuator with flexible cylinder and flexible rod was adopted. We proposed the foot motion to generate large upward force and minimize downward force. In this foot motion, to generate large upward force, the foot impacts on the water surface in the vertical direction with high speed, and to minimize downward force, the foot is pulled out of the water through the air cavity. And we propose leg mechanism generating this foot motion with flexible air cylinders and developed a 3 D.O.F leg mechanism. We designed and built a prototype water surface running machine. We experimentally investigated the motion of the body and foot, and the force acting on the foot. The prototype generated upward force, but didn't generate large impulse force when foot impacts on the water surface and minimize downward force acting on the foot by pulling the foot out of the water through the air cavity. Based on these experimental results, we proposed modified leg motion and mechanism to generate larger upward force and minimize downward force.
