Integrating fuzzy topological maps and fuzzy geometric maps for behavior-based robots

In behavior-based robots, planning is necessary to elaborate abstract plans that resolve complex navigational tasks. Usually maps of the environment are used to plan the robot motion and to resolve the navigational tasks. Two types of maps have been mainly used: metric and topological maps. Both types present advantages and weakness so that several integration approaches have been proposed in literature. However, in many approaches the integration is conducted to build a global representation model, and the planning and navigational techniques have not been fitted to profit from both kinds of information. We propose the integration of topological and metric models into a hybrid deliberative-reactive architecture through a path planning algorithm based on A* and a hierarchical map with two levels of abstraction. The hierarchical map contains the required information to take advantage of both kinds of modeling. On one hand, the topological model is based on a fuzzy perceptual model that allows the robot to classify the environment in distinguished places, and on the other hand, the metric map is built using regions of possibility with the shape of fuzzy segments, which are used later to build fuzzy grid-based maps. The approach allows the robot to decide on the use of the most appropriate model to navigate the world depending on minimum-cost and safety criteria. Experiments in simulation and in a real office-like environment are shown for validating the proposed approach integrated into the navigational architecture. (C) 2002 Wiley Periodicals, Inc.