Stepping to recover: A 3D-LIPM based push recovery and fall management scheme for biped robots

A 3D linear inverted pendulum model based push recovery & fall management scheme for small humanoid robots is presented in this paper. The size of step taken for push recovery is estimated based on inverted pendulum model considering change in kinetic and potential energies in case of external push. The direction and strength of push which is reflected by change in attitude of the robot is measured by a set of on-board inertial sensors. The proposed approach is then verified by a number of experiments on a 23-DOF small humanoid robot. And finally, if the push is too high and falling is inevitable, different safe-falling schemes are proposed in order to avoid or minimize the possible damage to the robot hardware.