From 2D Design of Underactuated Bipedal Gaits to 3D Implementation: Walking With Speed Tracking

Analysis and controller design methods abound in the literature for planar (also known as 2-D) bipedal models. This paper takes one of them developed for underactuated bipeds and documents the process of designing a family of controllers on the basis of a planar model and achieving stable walking on a physical 3-D robot, both indoors and outdoors, with walking speed varying smoothly from 0 to 0.8 m/s. The longest walk in a single experiment is 260 m over terrain with ±7° of slope variation. Advantages and disadvantages of the design approach are discussed.