Method and system for automatically attaching works onto vehicle bodies carried on a conveyor

A method for automatically attaching required works to main assemblies carried on a conveyor, comprising the steps of:

• (a) providing a movable base on which a robot is mounted and which is movable within a movement range thereof, at least part of the movable range being alongside of the conveyor;
• (b) providing a feeder for sequentially feeding required works to a predetermined position along the movement range of the movable base;
• (c) determining whether one of the main assemblies on the conveyor has passed through a first position upstream of the movement range of the movable base along the conveyor;
• (d) moving and positioning the movable base to a target position determined according to the predetermined position at which the feeder is arranged;
• (e) controlling the robot so as to grasp one of the required works from the feeder when the movable base is positioned at the target position;
• (f) moving and positioning the movable base on which the robot grasping the required work is mounted to a predetermined stand-by position of the movement range along the conveyor;
• (g) determining whether the one main assembly has arrived at a second position downstream of the first position and along the movement range of the movable base;
• and
• (h) controlling the robot so as to attach the required work to the predetermined portion at a predetermined time after determining that the main assembly has arrived at the second position, tracking the movable base to the conveyor so that a relative position deviation becomes zero, the relative position deviation in the direction of travel of the conveyor between at least one predetermined tracking point for the conveyor and a reference point predetermined for the movable base being detected sequentially.

A system for automatically attaching works to vehicle bodies carried on a conveyor, comprising:

• (a) first means carrying a robot for moving said robot within a movement range, at least one part of which being alongside of the conveyor;
• (b) second means for feeding sequentially plural kinds of the works which are different according to vehicle types of the vehicle bodies carried on the conveyor to different predetermined positions along the movement range of said first means;
• (c) third means for identifying the vehicle type of one of the vehicle bodies which has passed through a first position of the conveyor at an upstream of the part of movement range of the movable base along the conveyor when the vehicle body has passed through the first position;
• (d) fourth means for determining a target position in the movement range of said first means corresponding to one of the predetermined positions to which said second means feeds the required works on the basis of the identification result in said third means and for positioning said first means to the target position;
• (e) fifth means for controlling the robot so as to grasp one of the sequentially fed required works from said second means with said first means positioned at the target position;
• (f) sixth means for moving said first means along the movement range thereof, said first means being moved to the target position and thereafter moved to a stand-by position of the part of the movement range alongside of the conveyor at which said first means waits for a tracking operation to start;
• and
• (g) seventh means for detecting sequentially a deviation of a relative position toward a direction of travel of the conveyor between at least one predetermined tracking point located on the conveyor and a reference point located on said first means, said seventh means starting detection at a predetermined timing since one of the vehicle bodies which has passed through the first position has arrived at a second position downstream of the first position, said sixth means moving said first means to follow the conveyor so that the sequentially detected relative position deviation by said seventh means becomes zero, and said fifth means controlling the robot so as to attach the grasped work to a predetermined portion of the vehicle body which has passed through the second position with said first means tracking the conveyor.