  This paper contributes towards the benchmarking of control architectures for
bipedal robot locomotion. It considers architectures that are based on the
Divergent Component of Motion (DCM) and composed of three main layers:
trajectory optimization, simplified model control, and whole-body QP control
layer. While the first two layers use simplified robot models, the whole-body
QP control layer uses a complete robot model to produce either desired
positions, velocities, or torques inputs at the joint-level. This paper then
compares two implementations of the simplified model control layer, which are
tested with position, velocity, and torque control modes for the whole-body QP
control layer. In particular, both an instantaneous and a Receding Horizon
controller are presented for the simplified model control layer. We show also
that one of the proposed architectures allows the humanoid robot iCub to
achieve a forward walking velocity of 0.3372 meters per second, which is the
highest walking velocity achieved by the iCub robot.
