A Navigation Method Based on Topological Magnetic and Geometric Maps for Outdoor Mobile Robots

This paper proposes a novel navigation method based on topological magnetic and geometric maps for outdoor mobile robots. In this method, a state of a robot is represented by a travel distance and a lateral error, which is a distance from the travel path to the robot. In order to estimate the travel distance, a magnetic map which represents a magnetic field of the travel path is used. Since the magnetic field does not depend on moving objects, the travel distance can be robustly estimated against changes in geometric situations. However, deviating from the travel path is a fatal problem since the magnetic map does not record other magnetic fields of the travel path. To compensate this deviation, the lateral error is estimated by using geometric landmarks. Since this estimation is performed after the travel distance estimate, the lateral error can be stably estimated even if many moving objects surround the robot. As a result, the robot exactly navigates the travel path. Simulation and actual experiments are conducted to show the effectiveness and performance of the proposed method.