Gathering simulation of real robot swarm

Rad se bavi simulacijom problema grupiranja pomoću NXT robota. To su stvarni pokretni roboti koji se grupiraju sinkrono, bez bilo kakve globalne navigacije i komunikacije te uz ograničenu vidljivost. U prvom dijelu želim pokazati da se povećanjem sposobnosti tih robota slabih mogućnosti komunikacije i navigacije, oni mogu osposobiti za simuliranje složenih metoda grupiranja. Metode grupiranja skupina robota i timova robota su područja umjetne inteligencije koja se intenzivno proučavaju. Nekoliko je istraživača sastavilo teoretske algoritme za rješavanje problema grupiranja no oni su koristili samo matematičke ili robotske simulatore za testiranje svojih ideja. U drugom se dijelu rada pokazuje kako sam, nakon neznatne modifikacije Ando-algoritma i prilagođavanja realnim pokretnim robotima, konačno uspio ispitati tu metodu ne samo uz pomoć matematičkog simulatora već i sa stvarnim robotima.This article deals with simulations of gathering problems using NXT robots. These robots are real mobile robots and gather synchronously, with no global navigation and communication and only limited visibility. In the first part I want to demonstrate that by increasing the capabilities of those robots that have poor communication and navigation abilities, they can be made suitable for simulating complex gathering methods. The gathering methods of robot swarms and robot teams have been an intensively investigated area of artificial intelligence. Several researchers have made theoretical algorithms for the solution of gathering problems but they have only used mathematical or robot simulators to test their ideas. In the second part the article discusses how after slightly modifying the Ando-algorithm and adapting it to real mobile robots, in the end, I could test the method not only with the help of mathematical simulator but also with real robots

A Distributed Algorithm for Gathering Many Fat Mobile Robots in the Plane

In this work we consider the problem of gathering autonomous robots in the plane. In particular, we consider non-transparent unit-disc robots (i.e., fat) in an asynchronous setting. Vision is the only mean of coordination. Using a state-machine representation we formulate the gathering problem and develop a distributed algorithm that solves the problem for any number of robots. The main idea behind our algorithm is for the robots to reach a configuration in which all the following hold: (a) The robots' centers form a convex hull in which all robots are on the convex, (b) Each robot can see all other robots, and (c) The configuration is connected, that is, every robot touches another robot and all robots together form a connected formation. We show that starting from any initial configuration, the robots, making only local decisions and coordinate by vision, eventually reach such a configuration and terminate, yielding a solution to the gathering problem.Comment: 39 pages, 5 figure

Robots with Lights: Overcoming Obstructed Visibility Without Colliding

Robots with lights is a model of autonomous mobile computational entities operating in the plane in Look-Compute-Move cycles: each agent has an externally visible light which can assume colors from a fixed set; the lights are persistent (i.e., the color is not erased at the end of a cycle), but otherwise the agents are oblivious. The investigation of computability in this model, initially suggested by Peleg, is under way, and several results have been recently established. In these investigations, however, an agent is assumed to be capable to see through another agent. In this paper we start the study of computing when visibility is obstructable, and investigate the most basic problem for this setting, Complete Visibility: The agents must reach within finite time a configuration where they can all see each other and terminate. We do not make any assumption on a-priori knowledge of the number of agents, on rigidity of movements nor on chirality. The local coordinate system of an agent may change at each activation. Also, by definition of lights, an agent can communicate and remember only a constant number of bits in each cycle. In spite of these weak conditions, we prove that Complete Visibility is always solvable, even in the asynchronous setting, without collisions and using a small constant number of colors. The proof is constructive. We also show how to extend our protocol for Complete Visibility so that, with the same number of colors, the agents solve the (non-uniform) Circle Formation problem with obstructed visibility

Gathering simulation of real robot swarm

Rad se bavi simulacijom problema grupiranja pomoću NXT robota. To su stvarni pokretni roboti koji se grupiraju sinkrono, bez bilo kakve globalne navigacije i komunikacije te uz ograničenu vidljivost. U prvom dijelu želim pokazati da se povećanjem sposobnosti tih robota slabih mogućnosti komunikacije i navigacije, oni mogu osposobiti za simuliranje složenih metoda grupiranja. Metode grupiranja skupina robota i timova robota su područja umjetne inteligencije koja se intenzivno proučavaju. Nekoliko je istraživača sastavilo teoretske algoritme za rješavanje problema grupiranja no oni su koristili samo matematičke ili robotske simulatore za testiranje svojih ideja. U drugom se dijelu rada pokazuje kako sam, nakon neznatne modifikacije Ando-algoritma i prilagođavanja realnim pokretnim robotima, konačno uspio ispitati tu metodu ne samo uz pomoć matematičkog simulatora već i sa stvarnim robotima.This article deals with simulations of gathering problems using NXT robots. These robots are real mobile robots and gather synchronously, with no global navigation and communication and only limited visibility. In the first part I want to demonstrate that by increasing the capabilities of those robots that have poor communication and navigation abilities, they can be made suitable for simulating complex gathering methods. The gathering methods of robot swarms and robot teams have been an intensively investigated area of artificial intelligence. Several researchers have made theoretical algorithms for the solution of gathering problems but they have only used mathematical or robot simulators to test their ideas. In the second part the article discusses how after slightly modifying the Ando-algorithm and adapting it to real mobile robots, in the end, I could test the method not only with the help of mathematical simulator but also with real robots

Pattern Formation for Fat Robots with Memory

Given a set of $n\geq 1$ autonomous, anonymous, indistinguishable, silent, and possibly disoriented mobile unit disk (i.e., fat) robots operating following Look-Compute-Move cycles in the Euclidean plane, we consider the Pattern Formation problem: from arbitrary starting positions, the robots must reposition themselves to form a given target pattern. This problem arises under obstructed visibility, where a robot cannot see another robot if there is a third robot on the straight line segment between the two robots. We assume that a robot's movement cannot be interrupted by an adversary and that robots have a small $O(1)$-sized memory that they can use to store information, but that cannot be communicated to the other robots. To solve this problem, we present an algorithm that works in three steps. First it establishes mutual visibility, then it elects one robot to be the leader, and finally it forms the required pattern. The whole algorithm runs in $O(n) + O(q \log n)$ rounds, where $q>0$ is related to leader election, which takes $O(q \log n)$ rounds with probability at least $1-n^{-q}$. The algorithms are collision-free and do not require the knowledge of the number of robots.Comment: arXiv admin note: text overlap with arXiv:2306.1444

Circle formation by asynchronous opaque robots on infinite grid

This paper presents a distributed algorithm for circle formation problem under the infinite grid environment by asynchronous mobile opaque robots. Initially all the robots are acquiring distinct positions and they have to form a circle over the grid. Movements of the robots are restricted only along the grid lines. They do not share any global co-ordinate system. Robots are controlled by an asynchronous adversarial scheduler that operates in Look-Compute-Move cycles. The robots are indistinguishable by their nature, do not have any memory of their past configurations and previous actions. We consider the problem under luminous model, where robots communicate via lights, other than that they do not have any external communication system. Our protocol solves the  circle formation problem using seven colors. A subroutine of our algorithm also solves the line formation problem using three colors