Local/global frame switching in sensor-based outdoor navigation in a wheeled mobile robot

This paper presents a local/global frames switching in outdoor navigation of a four-wheeled mobile robot in an obstructed environment. Two laser range finders are equipped on the mobile robot in order to perform sensor-based obstacle avoidance without any a priori knowledge about its environment. Also, a GPS is mounted on the top of the robot so that the absolute location and the heading angle of the robot are known. The potential field method is utilized to create force fields around obstacles and a goal. Look-ahead control is adopted to steer the mobile robot in which a reference point located in front of the robot is dynamically changed such that the mobile robot is able to successfully maneuver among the obstacles and reach the goal. The proposed algorithm enables the mobile robot to follow the precise trajectory during navigation task under obstructed outdoor environment, despite its significant odometry errors.