A bio-inspired hexapod robot with noncircular gear transmission system

We report on the design and implementation of a simple bio-inspired hexapod driven by a single motor. Aiming for generating the dynamic locomotion of the robot, the design is based on the motion of a spring loaded inverted pendulum (SLIP) and then expanded to the hexapod morphology. The required speed variations and phase offsets of legs are achieved by utilization of non-circular gear pairs in the transmission system. Thus, the robot can be driven by a single DC motor without control effort. The designed alternating tripod gait allows the robot to adequately negotiate with rough terrain as well as to excite dynamic running behavior. The performance of the robot is evaluated experimentally and is quantitatively compared to the SLIP model.