MPC-Based Gait Generation for Humanoids: from Walking to Running

We present a Model Predictive Control (MPC) algorithm for 3D walking and running in humanoids. The scheme makes use of the Variable Height Inverted Pendulum (VH-IP) as prediction model, and generates a Center of Mass (CoM) trajectory and footstep positions online. The MPC works with the nonlinear dynamics by decomposing the problem into a vertical and a horizontal component. The vertical is solved first mak- ing the horizontal dynamics linear time-varying and therefore solvable in real-time. A stability constraint is incorporated to ensure internal stability. The algorithm is validated with dynamic simulations in DART.