Attitude Control of Legged Robot Emu on a Slope with Unknown Slope Angle

In this paper, we discuss motion control of legged robot Emu which is set on a slope whose slope angle is not known exactly. According to the stability analysis, we found that the control system proposed by us has a property of parametric stability. At the same time, we found that there is a certain problem. Therefore, to overcome the problem, we propose a new control law based on nonlinear observer.