Hybrid scheme for indoor localization and map building with a laser ranger finder and a local positioning sensor

Abstract

Localization and map building in an indoor environment are major problems for a mobile robot. There are two approaches to these problems: a metric approach and a topological approach. The metric approach uses various range sensors to determine the distance between an obstacle and the robot; the topological approach gives the robot its state on the basis of landmarks. Because both approaches have some advantages and disadvantages, researchers in the field of mobile robotics have combined the two approaches so that the robot can explore the environment autonomously. This so called hybrid approach still requires certain types of odometric information about as well as information on landmark recognition. To build a more accurate map and to localize precise the position and orientation of the robot, we use a local positioning sensor to compensate for the accumulation of wheel encoder errors and landmark recognition errors. In this paper, we propose a novel way of fusing a laser range finder, a local positioning sensor, and wheel encoders. The experimental results confirm that the robot can construct its own environment and localize itself more accurately and consistently than existing researches.