Toward Legless Locomotion Control

Abstract

Motivated by an error-recovery locomotion problem, we propose a control technique for a complex mechanical system by decomposing the system dynamics into a collection of simplified models. The robot considered, The Rocking and Rolling Robot (RRRobot), is a high-centered round-bodied robot that locomotes on a plane by swinging its legs and rocking on its shell. We identify the elements contributing to locomotion through two steps: 1) decoupling the leg-body rotation dynamics from the body-plane contact kinematics, and 2) decoupling the body rotational dynamics into dynamics along each rotational axis. We show, using simulation, that such decoupling provides a good approximation to RRRobot's locomotion and use these models to find an approximate control solution for RRRobot: a mapping between planar translation and leg motions.