Planning Of Landmark Measurement For The Navigation A Mobile Robot

Recognition of its current location is im- portant for a mobile robot to follow a planned path. Landmarks, which are assumed in the environment around the robot, are used to support this recognition. In this paper we propose a method for the robot to select the most suitable landmark among the measur- able landmarks from its current position by evaluating the error covariance update of the position estimation. We use the extended Kalman filter to update the po- sition estimation. We show the update behaviors of two types of landmarks : line type and point type. For the criteria of the evaluation we use the widths of the error ellipses, perpendicular to the direction of the course. Through the simulation of navigating a robot along the center lines of corridors the effectiveness of the proposed method is confirmed. ing landmarks the position estimation is updated in the same way. The behaviors of using two types of landmarks, a line type landmark and a point type one, are examined. The position estimation using a particular landmark is ex- pressed by an error ellipse which is derived from the error covariance update and which shows the directional error distribution of the estimated position error. Though it is favorable if the radius of the error ellipse is small in all di- rections, we think the width of the ellipse along the course is important and propose to use it as the criterion for the selection of the landmark. By the simulation of navigating a robot along the center lines of corridors the effectiveness of navigation based on the proposed landmark selection method is shown.