An anytime algorithm for optimal coalition structure generation

In multi agent system, how to find a coalition structure making the greatest profits in cooperation in the shortest time is an issue which has been given much attention. When finding the optimal coalition structure, if we make no any restriction on the searching space, we must search all the coalition structures. An anytime algorithm-LVAA(Lateral and Vertical Anytime Algorithm), designed in this paper, used a branch and bound technique and pruning function to simplify the searching space besides L₁, L₂ and L_n layers vertically and horizontally. Then, it find the optimal coalition structure value. The result of the experiment proved that it greatly reduced the searching space. When coalition values meet uniform distribution and normal distribution respectively, the searching times of LVAA can be reduced by 78% and 82% than Sandholm´s for agent number 18 and 23.