Force-controlled robot system with visual sensor for performing fitting operation

A force-controlled robot system for performing an operation of fitting a first workpiece into a second workpiece, comprising:

• a robot having a robot hand for holding the first workpiece and a force sensor for detecting force applied to the first workpiece held by said robot hand;
• a visual sensor for obtaining image data for obtaining relative position/orientation between said first workpiece and said second workpiece;
• and
• a control means for controlling said robot and said visual sensor, said control means including a fitting action performing means for making said first workpiece held by said robot hand approach said second workpiece and performing a fitting action under force control based on an output from said force sensor, a correcting means for obtaining workpiece position/orientation data representing the relative position/orientation between said first workpiece and said second workpiece based on image data obtained by said visual sensor and for correcting position and orientation of said robot based on the obtained workpiece position/orientation data in advance of said fitting action, and a discriminating means for obtaining fitting state data representing fitting state of said first workpiece in said second workpiece based on image data of the first and second workpieces obtained by said visual sensor and discriminating whether or not the fitting state is normal based on the obtained fitting state data after completing said fitting action.