Exploring an Unknown Graph by a Team of Robots Using Serendipity Rendezvous Algorithms

Dependence on a team of robots to carry out the exploration missions has many benefits such as speeding up the missions; provided that the coordination among robots is maintained. Many circumstances limit the communication which is crucial for the coordination among robots (e.g. impenetrable barriers, high temperature etc.). A periodic rendezvous strategy is considered in this dissertation a work-around in order to overlap communication ranges of the robots. Attending these periodic rendezvous sessions requires that the robots interrupt their current exploration progress periodically and traverse back to the rendezvous points (i.e. Interruptibility). During their trips to these points, they do not gain new knowledge since they cross already explored parts of the area. Therefore, using rendezvous strategies improves the team behaviour but has a negative impact on the time efficiency. Serendipity Rendezvous - the contribution of this dissertation - invests the dedicated time of Interruptibility trip in the inter-coordination among the robots by finding a serendipity path. This path is where the robot, which runs Serendipity Rendezvous, meets its colleagues accidentally on its way to the rendezvous point. The evaluation results show that Serendipity Rendezvous is able to mitigate the negative impact of Interruptibility while maintaining its positive impacts. Moreover, it provides a balance utilization of robots for the exploration activities. These results are achieved without affecting the already scheduled rendezvous. Hence, Serendipity Rendezvous optimizes periodic rendezvous sessions as long as the margin of the gaining knowledge by meeting other robots on the serendipity path is considered rewarded for the robots which run Serendipity Rendezvous.
About the Author: Since October 2009, Hamido Hourani is a scientific researcher at the IMA/ZLW & IfU of RWTH Aachen. Before, he worked as scientific researcher at the Institute for IT-Services - Stuttgart from 2008 until October 2009. Until 2008 he worked as system analyst at the Central Bank of Jordan and was employed as web developer at the private company in Jordan from 2005 until 2006. He finished his B.Sc.-Computer Science course in 2005 as second best of his year at the Al al-Bayt University in Jordan and afterwards completed his M.Sc. in Computer Science at the University of Jordan in 2008. In 2013, he got his doctorate degree from the faculty of mechanical engineering (RWTH Aachen). He mainly focuses on the multi-agent systems (swarm robotics) and distributed artificial intelligence.