Turning Maneuvers of a Multi-legged Modular Robot Using Its Inherent Dynamic Characteristics

This paper deals with the motion of a multi-legged modular robot. The robot consists of six homogenous modules, each of which has a body and two legs and is connected to the others through a three-degree-of-freedom joint. The leg joints are manipulated to follow periodic desired trajectories, and the joints between the modules act like a passive spring with a damper. This robot has characteristic dynamic properties. Specifically, a straight walk naturally turns into a meandering walk by changing the compliance of the joints between the modules without incorporation of any oscillatory inputs. We first show that this transition is excited due to a Hopf bifurcation, based on a numerical simulation and Floquet analysis. Following that, we examine whether the maneuverability and agility increase by utilizing the dynamic characteristics inherent in the robot. In particular, we conduct an experiment in which the robot pursues a target moving across the floor. We propose a simple controller to accomplish the task and achieve high maneuverability and agility by making the most of the robot´s dynamic features