Balance and Posture Control for Biped Robots

Abstract

This work presents an overview of a new approach for balance and posture control by regulating simultaneously the center of mass position and trunk orientation of a biped robot. After an unknown external perturbation deviates the robot from a desired posture, the controller computes a wrench (force and torque) required to recover the desired position and orientation, according to a compliance control law. This wrench is distributed to predefined supporting contact points at the feet. The forces at these points are computed via a constrained optimization problem, adopted from the grasping literature, which minimizes the contact forces while including friction restrictions and torque limits at each joint.