Applying Data Clustering Feature to Speed Up Ant Colony Optimization

Figure 4

The schematic diagram of ACO-SLC. Firstly, classify all points into compact classes. Secondly, the centroid of each class is regarded as a virtual city. And calculate a virtual TSP route. Then along the virtual route, join all classes. Thirdly, let ACO act on each class to get a local TSP route. Fourthly, join all local TSP routes along the virtual route to form the last route. The illustration of removing cross-edges from TSP route: at the left figure, AB and CD intersect each other. There is a principle that the shortest route is at the surface of a convex hull. Thus, edges AB and CD are the longer part of route and should be removed. Removing these two edges will generate shorter route (see right figure).