This controller was degined to adapt uncertained step height. Two controllers are applied in different levels (as shown in the following figure):
- The ladning modification (triggered by impulse detection) determines the updated level height, holds the landing foot position, and switchs the state machine to double support when the impact occurs.
- Due to the impact, the flat contacts on both feet might break (which is not desired in double support). In this case, the ankle stabilizer adjusts the ankle orientations based on a simplified model to restore the flat contacts.
In the following simulation, the upper body motion is controlled to cancel the momentum about the vertical axis induced by the lower body movement, to mitigate the slipping in the walking simulation.
