An optimization formulation for footsteps planning

We present a novel method to solve the problem of planning footsteps for a humanoid robot according to an arbitrary set of tasks. In this method, we consider the sequence of footsteps required to solve a task as a virtual kinematic chain that augments the state of the humanoid robot. We introduce this representation to formulate the footsteps planning as an iterative constrainted optimization problem where the footsteps are accounted for as additional degrees of freedom helping the robot in achieving its tasks. We demonstrate the efficiency and the generality of the method through three task scenarios for the humanoid robot HRP-2.