The stepping balance control strategy for humanoid robot based on capture point theory

Biped robots have been extensively studied due to the wide range of robot applications for its fast locomotion ability and good adaptation for complicated environments compared to other kinds of robots. The gait planning and balance control are the two main study fields in the past, but in this paper, the main research is only focused on the standing robot and the strategy to realize balance control of Nao robot. First of all, the stable region is analyzed when the robot is on the whole stiffness control and the starting condition for the stepping strategy based on the inverted pendulum model with a supporting plan is calculated. Then, the capture point is calculated by using the single inverted pendulum model according to the orbital energy theory. Last, the stepping forward motion is realized through the gait planning according to the previous research work. The proposed method is applied to the Nao robot for the stepping balance control and walking control successfully.