Coarse-to-fine robot localization method using radio fingerprint and Particle Filter

This paper presents the Particle Filter (PF) based localization method to fast estimate the accurate position of the mobile robot by using the radio-based maps. It is progressed by two steps, coarse and fine localization methods. First, as the coarse localization process, the fingerprinting method with the radio-based map is able to approximately find the location of the robot within tens of meters. And then, as the fine localization process, the PF localization with the grid-based map can improve the accuracy of the robot position within a few centimeters by using the coarse location estimated in the previous step. This approach has two major contributions; it can solve the local minima problem of the PF localization, and rapidly estimate the precise position of the robot with the small computational burden. An experiment has been performed in the office environments to verify the effectiveness of the proposed method. The experimental results show that the proposed method has superior performance compared to the normal PF localization method.