There's actually two companies that are actively working on something like that. One is called ekto vr (https://www.youtube.com/watch?v=m503RLeF7yk), and the other is called freeaim vr (https://www.youtube.com/watch?v=-ohNmVqglTY). The idea of using motorized shoes for vr, is actually a fairly old one. It was first demonstrated back in 2006 by the university of tsukuba (https://www.youtube.com/watch?v=AnBbtkxZBRI).