Abstract: Considering the special requirements for wall-climbing cleaning robot, a new type of omni-directional mechanism which can cross obstacles has been developed. This omni-directional mechanism can make the wall-climbing robot not only move in all directions on the wall without changing its pose or rotate at any angle at its original place but also overstep the obstacles such as the window frame in its routing.

Key words: omni-directional vehicle, wall-climbing robot, cross obstacle mechanism