Push Recovery for Humanoid Robots based on Linearized Double Inverted Pendulum
Biped robots have come a long way in imitating human being's anatomy and posture. Standing balance and push recovery are some of the biggest challenges for such robots. This paper presents a novel balance control scheme for a humanoid robot to recover from external disturbances. The proposed Linearized Double Inverted Pendulum, models the dynamics of a complex robot. The joint torque signals are generated along with ankle torque constraints to ensure the Center of Pressure stays within the support polygon. Simulation results show that the presented model can successfully recover from external disturbances while using minimal effort when compared to other widely used simplified models. It optimally uses the torso weight to generate an angular moment of inertia about the pelvis of the robot to counter-balance the effects of external disturbances. The proposed method was validated on simulated `TigerBot-VII', a humanoid robot.