We study models of mobile robots with limited capabilities that are deployed either on a cycle or an infinite line or on a segment. Robots start moving at the same time and when two robots collide their speeds and movement directions are instantaneously updated. Each of them possesses a collision detector and a clock to measure the times of its collisions. They do not have any knowledge on the total number of robots and do not have a common sense of direction. Besides, they neither have visibility nor control over their movements.We investigate the feasibility of the localization task in the cycle and the segment by bouncing robots: every robot should figure out the starting position and initial velocity of all the other robots. We consider two different scenarios when robots have common masses and speeds and robots of arbitrary masses and speeds. We give complete characterizations of all feasible configurations for the cycle in both scenarios.We study the survivability of bouncing robots. We say a robot survives if it never returns to its starting position. Non-surviving robots disappear from the environment.We provide sufficient and necessary conditions to have surviving robots in the cycle and in the segment. Finally we investigate communication protocols for bouncing robots that only communicate at the time of their collisions. We establish necessary and sufficient conditions for bouncing robots to perform gossiping, broadcasting and convergecast.iii
ContentsAbstract iii
List of Figures viiChapter 1. Introduction Computing the kth level of a set of lines 83vii CHAPTER 1 similarities with some models of gas particles, for instance in [36]. We also address related problems that we came to encounter after we proposed our model like the salmon problem and study communications protocols performed by these robots.Outline. In Chapter 2, we survey some models of mobile robots and we provide an overview of the state of the art of the field. We also motivate the models that we propose. In Chapter 3, we introduce our model of mobile robots that we call bouncing robots in two different flavors. We then study the task of localization also known as position discovery by bouncing robots. In our first model, robots move with the same speed while in the second one they have arbitrary speeds. We study the localization for one dimensional environments. We give algorithms to carry out localization and provide full characterizations of all feasible configurations. In Chapter 4, we study the survivability of bouncing robots that are deployed in a dangerous environment with deadly locations. When a robot visits some of such locations it is destroyed.In all those chapters we assume that robots can not communicate by any means however in Chapter 5 we allow bouncing robots to communicate and study different communication protocols carried out by them.In this section, we review some of the most relevant and related literature of mobile robots. We discuss different models of mobile robots, their environment, and the different timing ass...