tailieunhanh - Multi-Robot Systems From Swarms to Intelligent Automata - Parker et al (Eds) Part 6

Tham khảo tài liệu 'multi-robot systems from swarms to intelligent automata - parker et al (eds) part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 98 Roth et al. very conservative as agents are forced to take into account all possible contingencies. The Dec-Comm algorithm utilizes communication to allow agents to integrate their actual observations into the possible joint beliefs while still maintaining team synchronization. Dec-Comm Using communication to improve performance An agent using the Dec-Comm algorithm chooses to communicate when it sees that integrating its own observation history into the joint belief would cause a change in the joint action that would be selected. To decide whether or not to communicate the agent computes aNC the joint action selected by the Q-POMDP heuristic based on its current tree of possible joint beliefs. It then prunes the tree by removing all beliefs that are inconsistent with its own observation history and computes aC the action selected by Q-POMDP based on this pruned tree. If the actions are the same the agent chooses not to communicate. If the actions are different this indicates that there is a potential gain in expected reward through communication and the agent broadcasts its observation history to its teammates. When an agent receives a communication from one of its teammates it prunes its tree of joint beliefs to be consistent with the observations communicated to it and recurses to see if this new information would lead it to choose to communicate. Because there may be multiple instances of communication in each time step agents must wait a fixed period of time for the system to quiesce before acting. Figure 2 provides the details of the Dec-Comm algorithm. 4. Example To illustrate the details of our algorithm we present an example in the two-agent tiger domain introduced by Nair et al. Nair et al. 2003 . We use the tiger domain because it is easily understood and also because it is a problem that requires coordinated behavior between the agents. The tiger problem consists of two doors Left and RIGHT. Behind one door is a tiger and behind the other is a .