INDUSTRY: FUR

Customer Needs

At Kopenhagen Fur mink skins are handled and sorted before the five auctions every year. Some particular process steps in handling the mink skins are quite tough to manage manually in large numbers. Kopenhagen Fur saw an opportunity to use vision and robotics to handle this step and free up resources of the educated staff for other process steps like manual inspection and sorting. The solution was required to separate skins for further sorting or processing. Skins arrive stacked in wagons as shown in picture 1.

Solution

In a pre-project the laser scanners and laser cameras were evaluated with respect to their abilities to measure on the mink skin surface.  The initial goal was to be able to move skin directly from a wagon of stacked skins using laser scanners and a robot. Two laser scanners are used to compensate for the shadow effect introduced from each scanner; see picture 2. The degree of reflected light is combined with the 3D-measurements to create a single 3D-map as shown in picture 3 where the left side scanner data is visualized blue and the right is visualized green (combined areas are turquoise).

Information about the degree of reflected light along with the 3D-map is used to analyze where the separate skins are placed. The ambition is to figure out which ones are not covered by others since mink skins are very flexible and can interweave in quite difficult scenarios. Combined with the differences in surface structures, colors and sizes makes this step far from trivial.  An example where a number of skins are located - and two of them crossing each other - is shown in picture 4. We call this process Mikado – inspired from the game of same name.

The analysis will determine the coordinates of a number of candidates of skins in the wagon. These candidates must be from the top of the stack for the articulated robot to be able to pick them up - again look at picture 2. The robot will pick up the candidate skins and place them at a given position. When the robot has moved the number of skins away from the wagon, the procedure will start over with the 3D-scanning. Watch an example of this process in the videoclip.

Articles

Read the article “Robotten spiller Mikado med skind” (in Danish) about the ongoing project from January 2008 in the Danish weekly magazine for engineers “Ingeniøren”.