A hierarchical method to improve the productivity of multi-head surface mounting machines
This paper considers the problem of improving the productivity of multi-head surface mounting machines which are used to populate printed circuit boards with surface mount technology. The complexity of this problem is highly dependent on the specific number of heads which are used to pick and place components. This paper proposes a method for surface mounting machines with any number of heads. That is, our method can be applied regardless of the number of heads. The PCB assembly time depends on two decision variables: (I) assignment of reels to slots on feeder racks; and (2) sequencing of pick-and-place movements. These two problems are decomposed into a hierarchy of related subproblems. Since all subproblems in the hierarchy are known to be of a combinatorial nature and computationally intractable, we develop heuristics which are based on dynamic programming and the nearest neighbor traveling salesman problem technique. We implement the method as a computer program and perform computer simulations. The results are compared with a heuristic that is currently in use.
surface mounting machines printed circuit boards hierarchy of related subproblems heuristics dynamic programming nearest neighbor traveling salesman problem technique