  For humanoid robots to live up to their potential utility, they must be able
to robustly recover from instabilities. In this work, we propose a number of
balance enhancements to enable the robot to both achieve specific, desired
footholds in the world and adjusting the step positions and times as necessary
while leveraging ankle and hip. This includes improving the calculation of
capture regions for bipedal locomotion to better consider how step constraints
affect the ability to recover. We then explore a new strategy for performing
cross-over steps to maintain stability, which greatly enhances the variety of
tracking error from which the robot may recover. Our last contribution is a
strategy for time adaptation during the transfer phase for recovery. We then
present these results on our humanoid robot, Nadia, in both simulation and
hardware, showing the robot walking over rough terrain, recovering from
external disturbances, and taking cross-over steps to maintain balance.
