Localization and mapping in mobile robot systems

In this thesis improvement in localization and mapping in mobile robot systems have been performed. In the first study, the characteristics of IMU (Inertial Measurement Unit) sensors have been analyzed and their effect on mobile robot systems that use odometry for localization has been investigated. Moreover, they have been successfully applied to the odometric localization systems. As a second study, particle filter is applied to the odometry localization system. However, the experiments show that for the experimental set-up available in the laboratory, in which the experiments were performed, the particle filter is not an applicable method for the subjected standalone odometry based localization. After the improvement in odometry based localization in mobile robot system with IMU sensor, improved odometry based localization is applied to the single robot mapping. It is shown that the map also becomes more consistent and more accurate because of the improvement in localization. Furthermore, the effect of cumulative error in odometry based localization is studied in laser sensor based mapping systems to investigate different mapping methods for improving the consistency of the maps. Following that odometry based cooperative multi-robot map building is performed with different algorithms. Experiments show that cooperative multi-robot map building needs less time to construct the consistent map and is more robust than single-robot map building.