Research on the passive defense strategy of falling down protections of NAO humanoid robots

For the purpose of reducing the damage of NAO humanoid robots during Robocup compet itions when they fall, researches on passive defense strategy of the robot are carrying on. A robot motion simulation model is established based on the ADAMS software and the process of a robot falling down and impact forces suffered by a robot are analyzed in a virtua l environment. It is found out that the robot knee bending angle is a main factor which affects the impact force when the robot falls to the ground. The maximum impact force can be reduced effectively by means of lowering the center of gravity of the robot and touching the ground with forearms first instead of the head during it falls to the ground. It would be realized tha t the robot makes self-protection to reduce its damages in the game.