Feedback/feeeforward schemes for motion control of the CyberCarpet

The CyberCarpet is an actuated platform that allows unconstrained locomotion possibilities to a walking user for VR exploration. The platform has two actuating devices (linear and angular) and the motion control problem is dual to that of nonholonomic wheeled mobile robots. The main control objective is to keep the walker close to the platform center. Simple but global kinematic control schemes are presented, addressing in particular the handling of singularity issues. The feedback stabilizing part, which is based only on the user's pose information, is complemented by a feedforward term derived from a walker's velocity observer. Numerical and graphical simulation results are presented.