Undulatory locomotion of polychaete annelids: mechanics, neural control and robotic prototypes †

Abstract

The undulatory locomotion of polychaete annelid worms is studied as a biological paradigm of a versatile body morphology and effective motion control, adaptable to a large variety of unstructured and tortuous environmental conditions (water, sand, mud, sediment, etc.). Computational models of this type of locomotion have been developed, based on the Lagrangian dynamics of the system, on resistive models of its interaction with the environment and on neural control using central pattern generators. Simulation studies demonstrate the possibility to generate undulatory gaits, which are characterized by essential features of polychaete locomotion, based on these models. A lightweight robotic prototype has been developed, whose undulatory actuation achieves propulsion on sand.