Modeling and Control for a Biped Robot on Uneven Surfaces

Adaptability to the uneven surfaces is the key ability for a biped robot. This paper presents walking control algorithm for the biped walking on uneven surfaces, including the walking pattern generation and the sensory feedback control algorithm. The biped robot is modeled as the Passive Inverted Pendulum Model (PIPM) for the walking pattern generation. The generated pattern based on the PIPM enables the biped robot to walk stably on the flat ground with a natural human-like walking. Furthermore, the online sensory feedback controller is developed to deal with the unevenness of the surfaces. The controller consists of the body attitude control, the desired ZMP control and the nonlinear landing control. Influence of the biped robot's flexibility is considered into the control to reinforce the control effect. Finally, the walking experiment carried out on a biped robot confirms the effectiveness of the proposed walking controller.