Abstract
We have discussed a motion control of the legged robot Emu. In the research, we implicitly assumed that Emu stands upright on a level surface. However it is difficult to prepare the surface in practice because of an inclined plane. If we experiment in controlling Emu on the inclined plane under the assumption, Emu may fall down. Therefore we focus on an attitude control on a ramp of unknown slope. According to the stability analysis, we found that our proposed control system had a property of parametric stability. Thus we verify the parametric stability through some experiments.