Computer Engineering , Degree Project , Second Level , 30 higher education credits

The interest in indoor service robots is increasing day by day. Depending on the specific application, an array of issues and problems must be dealt with in order to obtain a stable and satisfactory behavior. A major problem that applies to all types of service robots (and robots in general) is concerning the navigation. Two ingredients are necessary in order to achieve navigation; a map of the working environment, and the ability to locate in the environment. Achieving these ingredients using classical approaches in robotics is afflicted with difficult problems. This report proposes an indoor navigation method influenced by stigmergy, which refers to the indirect communication that takes places between insects. A well-known example of stigmergy is the pheromone released by ants, which other ants can detect. Trails of pheromone make it possible for ants to optimize a path (i.e., find the fastest path) between two locations (e.g., the nest and the food). Stigmergy in general, can be said to, require very little information about the problem domain (compared to other approaches), when for example solving different types of optimization problems. The proposed navigation method is called gradient descent navigation, and requires very little information to manage navigation. For practical reasons, pheromone has not been used for the purpose of modifying the environment. Instead, an array of RFID tags has been used, which stores a so-called distance map. By using a distance map (i.e., by reading data stored in the tags), a robot is able to navigate. It is also shown how a distance map can be constructed using very little information.