A gluing process driven by a vision guided robotic system for footwear industry

The paper describes a gluing machine developed for the footwear industry and its recent improvements; it allows to glue the upper and rubber inserts on the soles of the shoes. To this aim, the machine was equipped with a Cartesian robot having a glue gun as end effector and with a vision system able to locate the position of the sole, arbitrarily placed on the worktop of the machine; the vision system also provides the outline of the soles, the surface on which to dispense the glue and information to plan the robot trajectory. Two procedures are presented for performing these operations; the first procedure is suitable for flat geometry soles for which the outline is clearly defined. The second procedure allows to treat three-dimensional soles with appreciable variation in height due to the presence of heels, raised outlines and tapered side surfaces. The final part of the paper illustrates the criteria adopted for planning the gluing trajectories and the experimental results of gluing operations obtained using the two mentioned procedures. In these operations, a laser pointer was fixed on the glue gun nozzle to simulate the glue spray with the beam of light emitted by the pointer.