This paper describes two indispensable techniques to develop a flexible sanding robot. One is the impedance model following force control for industrial robots which can delicately control the contact force acting between the sanding tool and the workpiece. The other is the surface following controller using the cutter location data to suitably keep the position and orientation of the sanding tool without complicated teaching process. The techniques are applied to an open architectural industrial robot FS-20 with an air-driven double action sander, so that a useful robot sander can be easily realized. Some sanding experiments have demonstrated that the proposed robot sander can successfully accomplish the sanding tasks of wooden workpieces with curved surface.
