Position and Orientation Measurement of a Mobile Robot by Image Recognition of Simple Barcode Landmarks and Compensation of Inclinations

摘要

A position and orientation measuring system for an indoor mobile robot is proposed based on “RECS” (Robot Environment Compromise System) concept. RECS concept makes it possible to develop the multipurpose robot by setting the environment so as that the robot can act skillfully. As the setting of the environment, a simple and cheep landmark is developed by using a commercial retro-reflect type reflection sheet and it is attached to the ceiling of a room. This landmark is based on white color and is not conspicuous to a human being at usual state, and is illuminated from the robot in order to be conspicuous only when the measuring procedure is needed. Considering economical efficiency and unobtrusiveness, this landmark can be employed at many points in the room. The robot can obtain landmark's image in a CCD camera and can know the absolute position of the landmark by reading the barcode. A calculating method of robot's position and orientation is newly proposed, which compensates two landmarks' images by information of robot's inclinations and uses them. Static and dynamic measuring accuracy of this system is experimentally inspected and it is less than 10mm and ideg in the neighborhood of two landmarks. By selecting appropriate two landmarks from many of them, this accuracy is thought to be kept in the wide area of the room.