Abstract-In this paper we present a case study of cooperation of a strongly heterogeneous robot team, composed of a highly articulated humanoid robot and a wheeled robot with largely complementing and some competing capabilities. By combining two strongly heterogeneous robots the diversity of accomplishable tasks increases as the variety of sensors and actuators in the robot systems is extended compared with a team consisting of homogeneous robots. The scenario describes a tightly cooperative task, where the humanoid robot and the wheeled robot follow for a long distance a ball, which is kicked finally by the humanoid robot into a goal. The task can be fulfilled successfully by combining the abilities of both robots. For task distribution and allocation, a newly developed objective function is presented which is based on a proper modeling of the sensing, perception, motion and onboard computing capabilities of the cooperating robots. Aspects of reliability and fault tolerance are considered.
I. INTROWith the growing importance of autonomous mobile robots in industrial and research applications the need to execute successfully challenging missions and tasks has also grown. To fulfill a large diversity of tasks with a sufficient reliability in the robot system, teams of robots are used instead of single highly specialized robots. The majority of research in robot teams considers homogeneous robots, most of them based on wheeled locomotion. The investigated tasks differ in the complexity of structure and cooperation, starting from basic tasks as foraging [1] or exploration of an area without a specific cooperation [2] up to problems with increase in communication and synchronization demands, e.g., cooperative box pushing [3] or cooperative surveillance of an area [4], [5] or soccer playing [6], [7], [8]. A classification of different stages of cooperation is given in [9]. A homogeneous robot team is usually equipped with identical sensors and actuators which usually differ only slightly, e.g., because of different wear and tear. Therefore, the diversity of tasks which can be accomplished by a homogeneous robot team is still quite limited. This drawback can be overcome by a team of heterogeneous robots, each or several of them equipped with different sensing, perception, motion and onboard computing capabilities. Several application have been investigated with robots, which differ only slightly in their capabilities. Although these robots are not fully identical, commonly they are still considered to form J. Kiener is with the Simulation,