Auto-nesting Of various Shapes on inconsistently shaped Leather Hides to maximize efficiency

Challenge Details

We produce finished leather hides (of 30-32 sq. ft. size), which are cut into specific shapes and size as per the customer requirements (mainly for the automotive industry). There are about 20 to 40 different shapes (Called Kits) that are requested by the customers. One such set of shapes is called a Kit. These shapes are cut from the leather hide. The shapes once cut are inspected for shape and dimensional accuracy by positioning them on Mylar templates. Mylar templates are plates which are made of Mylar material and are used as standards for checking the shapes. There are as many Mylar templates as the number of shapes. 

Currently, the placement of shapes/features is carried out manually, using trial and error method and his experience. First, the operator positions different shapes (templates) on the given leather hide. Various combinations are tried out to accommodate as many shapes as possible. He then marks the leather hide based on the final position of the shapes & cuts them accordingly. This process is not optimal, as it may not be possible to accommodate as many shapes and hence minimize wastage.

Thus, a system to optimally place the shapes on the leather hide with an objective of minimizing wastage of leather is required.

The system then feeds the hides into a clicking die to cut it into exact shape. The cut shapes will then be placed on a master mylar template to check for accuracy of cutting. Currently, this process of checking the shape and dimensional accuracy is manual in nature and is time-consuming. Therefore, a system which allows automatic nesting of features with minimal wastage of leather needs to be designed. In addition, a projection system to project different shapes on to a horizontal surface is needed. The shapes cut from the leather are placed on these ‘nominal’ projected shapes to verify the shape & dimensional accuracy.

The detailed requirements are listed below:

1. Identify non-defective area on the leather hide
2. Position as many shapes to be cut out from the leather in an optimal manner, with an objective of minimizing the wastage. Provide a visual display of the leather along with the shapes.
3. Provide a master profile (replacement of Mylar as a projection on a horizontal surface) for comparing the cut shape.
4. The system should capture the image of each leather hide and analyze the non-defective area. If the defective areas are already marked, the same should be accounted for.
5. The system should also calculate and display the wastage percentage for each hide.
6. The system should project the Mylar template onto a horizontal surface and should automatically detect the exactness of the dimension of the cut feature.
7. The system should be cost effective.
8. The system should be fast enough to verify the dimensions of 10 features in 3 mins.
9. The system should be replicable to other workstations.