Character-based mobile robot navigation

We describe a method for navigating a mobile robot in the environment using signboards in scenes as landmarks. This method will enable us to realize human-like navigation and map-generation, and also can benefit human-robot communication. We choose signboards on walls and doors as landmarks. An environment map that contains the approximate position of each signboard in the environment is generated by the robot when the robot explores the environment the first time, and it will be used for re-localizing and navigating the robot afterward. First, characters in scene images are detected by using several heuristics of characters and character lines. Then, we calculate the relative orientation of the camera and a detected signboard from a single view using two methods based on the geometry of perspective projection. Finally, we reconstruct a distorted signboard image using two corresponding methods, and this makes the recognition of characters under a wider range of viewing condition much easier