Progressive Negotiation For Time�Constrained Autonomous Agents �

We address in this paper a problem of autonomous agents performing in a common environment where each agent has its goal to achieve before a given dead� line. Agents must be able to determine their local plan and to react properly to local plans of other agents be� fore its given deadline. The solution presented consists of using progressive planning that adapts the detail of local plans according to local deadlines and progressive negotiation model that organizes con�icts between lo� cal plans in categories and solves them progressively from the mandatory category to optional one. Our negotiation model is based on the modi�ed PGP �Par� tial Global Planning � approach � named Partial Global Progressive Planning �PGPP � which is an incremen� tal strategy to insert partial local plans progressively one by one. This strategy consists of discarding op� tional partial local plans of an agent when deadline is met or global consistency is violated. We will shows that this approach reduces the costs of detecting and solving con�icts. This approach can be seen as an im� portant step towards the application of contract�net type systems to real�world problems