Preview Control with an Angle Adjustment Strategy for Robust Real-Time Biped Walking Pattern Generation

To enhance the robustness in tolerance for ZMP design imperfection and for uncertain external disturbances in online biped gait generation, a modified preview control strategy with angle coefficient adjustment is presented. First, an offline walking pattern generator based on ZMP stability criterion and an online one using ZMP preview control with an observer integrated are built. Then the concept of angle coefficient is proposed and the method for angle coefficient real-time adjustment is presented. To evaluate the effectiveness of proposed method, simulation experiments are conducted with a 10 DOFs prototype. The results show that, using the proposed method, the robot prototype is capable of reducing the center of mass (COM) trajectory tracking error; the robot prototype is capable of reducing walking yaw in spite of ZMP design imperfection and modeling error; the robot prototype is capable of walking stably through uneven path surfaces.