Motion Planning for Stepping On/Off Obstacles by Humanoid Robot

This paper presents a humanoid robot BHR-2 capable of performing stepping on and off a flat obstacle of known dimension. The trajectory comprises of two phases for the task completion. The first phase starts with the left foot raised from the ground and reaching the obstacle base tracking the trajectory points generated by spline interpolation. The end of the first phase is the state when both feet are on the obstacle. The second phase starts with the final point of the first phase. First, the left foot is raised slightly above the obstacle and then step forward to descend to the ground followed by right foot accordingly. The dynamic stability during the execution of stepping on/off is ensured by incorporating the ZMP criterion. The motion planning for stepping on/off is simulated accurately and is also verified through experimentation.