Deformation compensation for continuous force control of a wall climbing quadruped with reduced-DOF

A lightweight wall climbing robot with reduced degrees of freedom (DOF) is under development. This robot consists of three main components. The first component is a quadruped walking robot with reduced-DOF. Since lightweight is an important feature for wall-climbing robots, the DOF of this robot were reduced until three, without hampering its ability as a walking robot. The second one is a sucker using a blower. The adhesion force with a blower is weaker than with a vacuum pump, but the blower can deal better with air leakage. The sucker developed in this research can adhere to walls with many slits and uneven ceiling. Finally, the last component is an ankle joint with wide movable range. This mechanism is indispensable for walking freely in any environment and transferring from wall to wall, wall to ceiling and ground to wall. Moreover, the appropriate compensated motion for wall climbing is considered. The structure of the wall climbing robot has been deformed by the gravity effects. Therefore, the compensated motion should be indispensable for its smooth climbing motion. Wall climbing experiments using the walker developed in this research have been performed with the proposed compensated motion