Dynamic Walking on Randomly-Varying Discrete Terrain with One-step Preview

Authors: Quan Nguyen, Koushil Sreenath, Ayush Agrawal, Xingye Da, William Martin, Hartmut Geyer, Jessy Grizzle

An inspiration for developing a bipedal walking system is the ability to navigate rough terrain with discrete footholds like stepping stones. In this paper, we present a novel methodology called the two-step periodic gait library to overcome the problem of dynamic walking over stepping stones with significant changes to step length and step heightfor every step. The gait optimization not only considers the desired location of the next footstep but also the current configuration of the robot, therefore resolving the problem of step transition when we switch between different walking gaits. We then use gait interpolation to generate the desired walking gait in real-time. We demonstrated the method on a planar dynamical walking model of ATRIAS, an underactuated bipedal robot walking over a randomly generated stepping stones with step length and step height changing in the range of [30:80] (cm) and [-30:30] (cm) respectively. Experimental validation on the real robot was also successful for the problem of dynamic walking on stepping stones with step lengths varied within [23:78] (cm) and average walking speed of 0.6 (m/s).