Automatic buckle assembly for sandals

Automatic buckle assembly for sandals Project type: Automatisation Date 2019 The customer designs a fully automatic series machine that produces the semi-finished product “Sandalen Lederbelmen mit Klammer”. Several robots and image processing systems are provided in the machine. The image processing is to be used at 3 stations. Station 1: Position recognition of the clamps Station 2: Leather strap position detection Station 3: Quality control of the semi-finished product A prototype has already been built. This is now to be optimized. + The clamp feeder can be changed + The clamp station is provided by the supplier and thus cannot be changed shall be: + All three image processing stations can be projected completely freely. + There are no specifications according to the inspection system (Matrix/Linescan/2,5D/3D, etc.) + There is no manufacturer specification Fig. Fig. 1: Construction of the entire machine Station 3 Station 2 Station 1 Station 1: Position recognition of the clamps Instantaneous mechanical structure: + The brackets are transported from a bunker to the belt + The brackets are usually isolated + The brackets are supplied in a single type It may happen that a false bracket is mixed in. It may happen that defective brackets are included, in which For example, the middle hook is missing + The tape has a width of 400mm + In the prototype, a backlighting of 300 mm is installed + In the prototype, there is additionally a square dark field illumination around the image field Built around + In the prototype, the camera looks 90° from above at the backlight and searches for the Brace contours + In the dark field, the camera searches for the lettering Problems with prototype: - at approx. 0.5% of the tests, a bracket lying incorrectly is recognized as being lying around correctly and thus in general. The clamp is then mounted by the robot. The semi-finished product is therefore scrap. - There will be too few i.O. brackets recognized as such. The image field is thus unnecessarily often cleared and re-equipped. As a result, the required clock rate is not achieved. Requirements Station 1: + Position detection of the clamps to 0.1 mm accuracy (x/y + rotation) + position detection of the clips ( upward or downward font) + Clock rate below 0.5 seconds per bracket + Sorting out incorrect and defective brackets Station 2: Position detection of the leather straps Instantaneous mechanical structure: + The leather strap is gripped by the robot and placed on a backlighting + The camera looks 90° from above at the backlight + The image field is approx. 230 mm x 230 mm + The camera searches for the leather contour and passes the x/y + rotation data to the Robotics + The desired contour is given to the system from the CAD data + The leather straps are supplied with pure variety (leather type and shoe size always the same) Problems with prototype: - When the leather straps are cut from the roll end, they are relatively strongly curved. They then do not lie flat on the backlight. As a result, the camera cannot recognize the position as accurately as required. Requirements Station 2: + Position detection of the leather straps to an accuracy of 0.1 mm (x/y + rotation) + cycle rate below 0.5 seconds per leather belt Station 3: Quality control of the semi-finished product Instantaneous mechanical structure: + The leather strap is removed from the clamp station by the robot and placed on a Place of test + Another robot guides a 3D laser line system over the mounted buckles +field width instantaneously approx. 40 mm + The positions of the buckles are checked for the following characteristics: Presence of the buckle Correct position of the buckle (upward script) Presence of brackets Positions of brackets + The semi-finished products are produced in pure variety + Buckles can be used in all conceivable colors + brackets can be silver or black + Leather can be used in all possible colors Problems with prototype: - Examination of black brackets takes too long - Due to the too slow testing, the cycle rate of the complete system goes down - The angle of the buckles should be in relation to the lowest edge of the semi-finished product are controlled. This is not possible with the current image field. Requirements Station 3: + Increase clock speed + Decrease pseudo-committee