1 Introduction
The cooperative control problem is characterized by three attributes: 1) complexity, 2) information structure, and 3) uncertainty. To address complexity and, possibly to accommodate the prevailing information pattern, an innovative hierarchical decomposition is used [1], [2]. Figure 1 illustrates a general architecture for cooperative control and task apportionment among multiple vehicles. One control level and three decision levels are introduced. At decision level 1 is the vehicle agent that does path planning, trajectory generation, and maintains models of terrain, threats, and targets. At decision level 2 is the sub-team agent which coordinates the activities of any tasks that require more than one vehicle. to accomplish. If the sub-team has more than one task, then the agent apportions the vehicles to the tasks. Also, this agent does rendezvous coordination as well as sensor, weapon, decoy, and jamming coordination. The team agent, at decision level 3, is responsible for meeting the mission objective, determining sub-objectives for the sub-teams, and apportioning resources and tasks.