Constraint-based landmark localization

We present an approach to the landmark-based robot localization problem for environments, such as RoboCup middle-size soccer, that provide limited or low-quality information for localization. This approach allows use of different types of measurements on potential landmarks in order to increase landmark availability. Some sensors or landmarks might provide only range (such as field walls) or only bearing measurements (such as goals). The approach makes use of inexpensive sensors (color vision) using fast, simple updates robust to low landmark visibility and high noise. This localization method has been demonstrated in laboratory experiments and RoboCup 2001. Experimental analysis of the relative benefits of the approach is provided.