Attitude control of legged robot Emu on ramp with unknown slope $verification of parametric stability by experiments

We have discussed a motion control of the legged robot Emu and we realized some non-stationary motions (for example, some motions of a robot sitting down and standing up, moving arms, standing upright, and so on) of Emu as the results. In the research, we implicitly assumed that Emu stands uptight, sits down and stands up on a level surface. It is difficult, however, to prepare the surface because it inclined probably in practice. If we experiment in controlling Emu on the inclines plane under the assumption that Emu moves on a level surface, Emu may fall down. Therefore we focus on an attitude control of Emu on a ramp with unknown slope. According to the stability analysis, we found that our proposed control system had a property of parametric stability. We also verified a validity of the parametric stability through some experiments.