Clock-turning gait synthesis for humanoid robots

Turning gait is a basic motion for humanoid robots. This paper presents a method for humanoid turning, i.e. clock-turning. The objective of clock-turning is to change robot direction at a stationary spot. The clock-turning plan-ning consists of four steps: ankle trajectory generation, hip trajectory generation, knee trajectory generation, and inverse kinematics calculation. Our proposed method is based on a typical humanoid structure with 12 DOFs (degrees of freedom). The final output of clock-turning planning is 12 reference trajectories, which are used to control a humanoid robot with 12 DOFs. ZMP (zero moment point) is used as stability criterion for the planning. Simulation experiments are conducted to verify the effectiveness of our proposed clock-turning method.