Discrete-status-based localization for indoor service robots

This paper proposes a new localization strategy for indoor service robots. A mobile robot localization problem is difficult to solve by a single continuous algorithm. Major difficulties include dynamic changes of the real world, various uncertainties, limitation of sensor information, and so forth. To develop a practical localization solution, this paper proposes an integrated localization strategy based on the discrete status of the mobile robot. Uncertainties of navigation are specified and classified into discrete status, and then modeled as a Petri net-based discrete localization system. The proposed algorithm integrates developed computational schemes and robot behaviors with respect to the defined status. Major criteria of status discretization include geometric properties of the environment, existence of dynamic obstacles, and reliability level of the estimated position. An efficient map-matching scheme and a map-building strategy are developed toward practical implementations. This paper focuses on providing a synthesized practical localization method, which can deal with various uncertainties by explicit discretization of robot status. The feasibility of the proposed method is experimentally verified with prototype public service robots in dynamic real environments.