In the present study, we investigate and analyze the behavior of explorer agents. We perform a number of experiments with single and multiple agents and we obtain a number of corresponding results. First, we decouple the agent's functional=motivational system from its cognitive=representational system and show that intricate regulation is necessary to achieve effective and efficient behavior. In the multiple agents case, we extend the single agent behavioral model with a form of sociality selected from a progression of alternatives designed and evaluated. We also show how the general regulation perspective allows for design and analysis of explorer systems. We do not miss to provide variations of the problem and potential applications all along the way.
INTRODUCTIONExploration is a typical problem encountered in the behavior-based robotics literature and owes its name and formulation to one of the very first projects in behavior-based robotics that aimed-somewhat futuristically-at the exploration of Mars (Angle and Brooks 1990): a set of robotic agents lands on a planet with the mission to explore its surface for samples of minerals having certain properties. The robots arrive in a spaceship that serves as the planetary base in the course of the mission. The mission is accomplished when the whole surface contained within a certain distance from the base is explored. We ought to note that this exploration problem is described as a sampling one, where the agents have to pick some mineral samples from the sources of interest. However, in practice, in the corresponding literature, the problem is tackled as a sweeping one, where the agents have to exhaust the sources of interest (cf. for instance Brooks and Flynn (1989), Beckers et al. (1994)). In both cases, it is a field coverage problem: the termination criterion is that all the assumed surface should be explored. In the same course of ideas as the researchers in behavior-based robotics, we have adopted the sweeping variant that lends itself to a more worldly instantiation: let us imagine a set of robotic agents thrown in a garage, a subway station, or another delimited area, with the mission to clean away all objects of a given type, usually litter, such as empty soda cans, nylon bags etc. The agents are supposed to return to their base once their mission is accomplished: the subway-cleaner robots are going to wake up and enter in activity outside operation hours, for instance at night, and return to their base definitely once they have cleaned everything, before the reopening of the station. With respect to sampling, sweeping appears therefore a more primitive problem, since it assumes the same functionality for navigation, detection and localization, but without necessitating a sophisticated spatial reasoning: in the case of sampling, the robot has to remember, in a way or another, all the sources of mineral that it has already explored, so as to avoid visiting them again, while in the sweeping case, the fact that a mineral source has been visited does not have...