To flock or not to flock: Pros and cons of flocking in long-range "migration" of mobile robot swarms


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Bilgisayar Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2008

Öğrenci: FATİH GÖKÇE

Danışman: EROL ŞAHİN

Özet:

Every year, certain animal and insect species flock together to make long-range migrations to reach their feeding or breeding grounds. A number of interesting observations can be made regarding this phenomenon. First, individuals tend to create large flocks, which can include millions of individuals in fishes, for these migrations. Second, migrations typically cover long distances. Third, despite all kinds of disturbances affecting the individuals during these migrations, the flocks can reach the very same breeding or feeding grounds with remarkable accuracy. Biological studies indicated that these animals mainly use the magnetic field of earth (among many other environmental cues) to determine the direction of their travel. It was also claimed that migrating in flocks has been the key factor behind the accuracy of reaching the same grounds at the end of the migration. In this thesis, we take a constructivist approach towards investigating the effects of flocking in long-range travels using a swarm of physical and simulated mobile robots. Specifically, we extend a self-organized flocking behavior that was developed by Turgut et al. (2008) that allows the long-range migration of a robotic swarm in space using the magnetic field of the earth. Using this behavior, we analyze how the accuracy of the robotic swarm reaching a particular "breeding ground" is affected by four factors; namely, (1) averaging through the heading alignment, (2) noise in sensing the homing direction, (3) differences in the characteristics of the individuals, and (4) disturbances caused by the proximal interactions of the robots during flocking. Through systematic experiments with physical and simulated robots, we analyze how these factors affect the accuracy along with the flock size and different sources of noise.