Qualitative Hybrid Control of Dynamic Bipedal Walking

We present a qualitative approach to the dynamical control of bipedal walking that allows us to combine the benefits of passive dynamic walkers with the ability to walk on uneven terrain. We demonstrate an online control strategy, synthesizing a stable walking gait along a sequence of irregularly spaced stepping stones. The passive dynamic walking paradigm has begun to establish itself as a useful approach to gait synthesis. Recently, researchers have begun to explore the problem of actuating these passive walkers, to extend their domain of applicability. The problem of applying this approach to applications involving uneven terrain remains unsolved and forms the focus of this paper. We demonstrate that through the use of qualitative descriptions of the task, the use of the nonlinear dynamics of the robot mechanism and a multiple model control strategy, it is possible to design gaits that can safely operate under realistic terrain conditions.