Passive undulatory gaits enhance walking in a myriapod millirobot

The design and modeling of a segmented myriapod millirobot with a compliant body is presented. A dynamic model is used to demonstrate how body undulations can result from only varying the phase difference in the stance change between adjacent segments - even with passive intersegmental connections - and how these gaits affect locomotion. Different gaits are demonstrated experimentally in a 20-leg, 2.2 gram millirobot, and the resulting motion is compared to that predicted by the simulation. Both simulation and experiments show that undulatory gaits can increase the average speed of straight-line locomotion as compared to non-undulatory gaits for the same stepping frequency. The model and the millirobot can be used concurrently with biological studies to understand aspects of myriapod locomotion. This robot is also a useful tool to gain insight into how flexibility can be introduced into robots at this scale to enhance locomotion.