Vision-based robot navigation and map building using active laser projection

This paper presents a vision-based approach to mobile robot navigation and map building using laser projection. A CCD cameras is installed on the ceiling observing the work space of a mobile robot. The mobile robot is equipped with a laser-vision system composed of a laser line projector and a CCD camera. Map building is performed by reconstructing the projection of the line from the actively-controlled laser projector. By exploring within the field of view of a ceiling-mounted CCD camera, the local map is built by the onboard laser-vision system. Based on a set of pre-selected features that can be detected on top of the mobile robot by the ceiling-mounted camera, on-line calibration of the coordinate transformation from the mobile robot to the ceiling-mounted camera can be established. This allows the system to keep track of current location of the robot in an unknown environment. The 3-D map reconstructed under a ceiling-mounted camera can then be used for mobile robot navigation and control in the unknown environment. The proposed system has been successfully validated by navigating a custom mobile robot equipped with the laser-vision system in an indoor laboratory environment.