Integration of Variable-height and Hopping Strategies for Humanoid Push Recovery

In this study, we present a framework to en-sure seamless transition in humanoid push recovery involving hopping strategy. We propose a method to adaptively change the time constant that integrated the ankle strategy and variable height strategy. This framework excites a hopping motion against a large disturbance, which provides a seamless transition from the variable height to the hopping strategies. We analyze the applicable region of each strategy based on the simplified model. Moreover, we show that the hopping strategy prevents falling through whole-body dynamic simulations.