The Flatworm-like Pedal Locomotory Robot WORMESH-I: Locomotion Based on the Combination of Pedal Waves

Abstract

Flatworms are dorsoventrally flattened, bilaterally symmetrical, and soft-bodied. They can move on rough terrain, swim, and climb a shore reef using pedal locomotion and continuous gliding propulsion along the bottom of the body. Inspired by the flatworm, we have been developing the flatworm-like robot, which consisted of the same modules connected via multi degree of freedom (DOF) joints. The pedal locomotion is the primary locomotor mode, however, motion generation is highly complex. Therefore, this research focused on locomotion of flatworm-like pedal locomotory robot for the translational, spinning, omnidirectional motions. We proposed a new method of generating various locomotion combining multiple pedal waves. The proposed method was verified with a simulator with a physics engine. After this verification, we analyzed locomotion characteristics considering 1) the parameters of pedal wave based on the serpenoid curve; initial winding angle $\alpha$ and temporal frequency of the traveling wave $\omega, 2$) number of robot modules arranged in a matrix form; 3, 4 and 8. The similation results showed the relationship between translational and angular velocity of COG and the parameters of pedal wave.