Push recovery is an important capability for a biped to safely maneuver in a real dynamic environment. In this paper, a generalized push recovery scheme to handle pushes from any direction that may occur at any walking phase is developed. Using the concept of walking phase modification, a series of systematic push recovery scheme that takes into account the severity of the push is presented. The result is that a bipedal robot could adapt to pushes according to the magnitude of disturbance and determine the best course of action. A number of push recovery experiments with different walking phases and push directions have been carried out using a 12-DOF humanoid robot model in dynamic simulations. The versatility and potential of the overall scheme is also demonstrated with the bipedal robot balancing on an accelerating cart.
Approximate hybrid model predictive control for multi-contact push recovery in complex environments
