Enhanced Map-Based Indoor Navigation System of a Humanoid Robot Using Ultrasound Measurements

Abstract

During recent years, walking humanoid robots have gained popularity from wheeled vehicle robots in various assistive roles in human's environment. Self-localization is a necessary requirement for the humanoid robots used in most of the assistive tasks. This is because the robots have to be able to locate themselves in their environment in order to accom-plish their tasks. In addition, autonomous navigation of walking robots to the pre-defined destination is equally impor-tant mission, and therefore it is required that the robot knows its initiate location precisely. The indoor navigation is based on the map of the environment used by the robot. Assuming that the walking robot is capable of locating itself based on its initiate location and the distance walked from it, there are still factors that impair the map-based navigation. One of them is the robot's limited ability to keep its direction when it is walking, which means that the robot is not able to walk directly from one point to another due to a stochastic error in walking direction. In this paper we present an al-gorithm for straightening the walking path using distance measurements by built-in sonar sensors of a NAO humanoid robot. The proposed algorithm enables the robot to walk directly from one point to another, which enables precise map-based indoor navigation.