Emotion-based control of cooperating heterogeneous mobile robots

Previous experiences show that it is possible for agents such as robots cooperating asynchronously on a sequential task to enter deadlock, where one robot does not fulfill its obligations in a timely manner due to hardware or planning failure, unanticipated delays, etc. Our approach uses a formal multilevel hierarchy of emotions where emotions both modify active behaviors at the sensory-motor level and change the set of active behaviors at the schematic level. The resulting implementation of a team of heterogeneous robots using a hybrid deliberative/reactive architecture produced the desired emergent societal behavior. Data collected at two different public venues illustrate how a dependent agent selects new behaviors (e.g., stop serving, move to intercept the refiller) to compensate for delays from a subordinate agent (e.g., blocked by the audience). The subordinate also modifies the intensity of its active behaviors in response to feedback from the dependent agent. The agents communicate asynchronously through Knowledge Query and Manipulation Language via wireless Ethernet.