Experimental evaluation of a hybrid position and force surface following algorithm for unknown surfaces

This paper experimentally implements a surface following algorithm for unknown surfaces under a hybrid position and force scheme. The mechanization uses a low friction roller at the end of a two-link manipulator so that primarily the normal force is measured. With the normal force information and joint angle information, the surface normal direction is calculated and a position reference is calculated along the surface tangent. Experimental evaluation shows the algorithm works for a line, a concave arc, and a convex arc. Also, when different force levels are commanded or different controllers are used, the algorithm still performs well. Thus, the algorithm allows a constant force to be applied while following a surface whose shape is not known a priori.