Swarm robotics: Cooperative navigation in unknown environments

Swarm Robotics is garnering attention in the robotics field due to its substantial benefits. It has been proven to outperform most other robotic approaches in many applications such as military, space exploration and disaster search and rescue missions. It is inspired by the behavior of swarms of social insects such as ants and bees. It consists of a number of robots with limited capabilities and restricted local sensing. When deployed, individual robots behave according to local sensing until the emergence of a global behavior where they, as a swarm, can accomplish missions individuals cannot. In this research, we propose a novel exploration and navigation method based on a combination of Probabilistic Finite Sate Machine (PFSM), Robotic Darwinian Particle Swarm Optimization (RDPSO) and Depth First Search (DFS). We use V-REP Simulator to test our approach. We are also implementing our own cost effective swarm robot platform, AntBOT, as a proof of concept for future experimentation. We prove that our proposed method will yield excellent navigation solution in optimal time when compared to methods using either PFSM only or RDPSO only. In fact, our method is proved to produce 40% more success rate along with an exploration speed of 1.4x other methods. After exploration, robots can navigate the environment forming a Mobile Ad-hoc Network (MANET) and using the graph of robots as network nodes

Integrazione e validazione di OMNeT++ e Gazebo per sistemi multi-robot mediante un caso d'uso

Sistemi multi-robot a mobilità autonoma necessitano di simulatori che simulino in maniera accurata entrambi gli aspetti di gestione della rete di comunicazione e interazione dei robot con l'ambiente. Strumenti di questi tipo si ricavano dall'integrazione di simulatori specializzati nella simulazione di un singolo aspetto. In questa tesi viene descritta la realizzazione di un sistema integrato formato dall'unione di OMNeT++ e Gazebo. Il sistema viene quindi validato mediante un caso d'uso, una forma di mobilità basata sulle molle virtuali. Uno sciame di droni, connesso dalle molle virtuali, viene condotto da un drone leader in un ambiente cittadino. Dato che tale ambiente presenta degli ostacoli, i droni sono equipaggiati con sensori di prossimità allo scopo di evitare collisioni, prendendo decisioni su come muoversi per evitare l'ostacolo utilizzando anche qui le molle virtuali. Viene quindi valutata tale forma di mobilità

Behaviour Based Simulated Low-Cost Multi-Robot Exploration

Institute of Perception, Action and BehaviourThe use of multiple robots for exploration holds the promise of improved performance over single robot systems. To exploit effectively the advantage of having several robots, the robots must be co-ordinated which requires communication. Previous research relies on a fixed communication network topology, a single lead explorer, and flat communication. This thesis presents a novel architecture to keep a group of robots as a single connected and adaptable communication network to explore and map the environment. This architecture, BERODE (BEhavioural ROle DEcentralized), aims to be robust, efficient and scalable to large numbers of robots. The network is adaptable, the number of explorers variable, and communications hierarchical (local/global). The network is kept connected by an MST (Minimum Spanning Tree) control network, a subnetwork containing only the minimum necessary links to be a fully connected network. As the robots explore, the MST control network is updated either partially (local network) or globally to improve signal quality. The local network for a robot is formed by the robots that are within a certain retransmission distance in the MST control network. BERODE implements a hierarchic approach to distributing information to improve scalability with respect to the number of robots. The robots share information at two levels: frequently within their local network and less frequently to the entire robot network. The robots coordinate by assuming behaviours depending on their connections in the MST control network. The behavioural roles balance between the tasks of exploration and network maintenance where the Explorer role is the most focused on the exploration task. This improves efficiency by allowing varying number of robots to take the Explorer role depending on circumstances. The roles generate reactive plans that ensure the connectivity of the network. These plans are based on the imposition of heterogeneous virtual spring forces. Our simulations show that BERODE is more efficient, scalable and robust with respect to communications than the previous approaches that rely on fixed control networks. BERODE is more efficient because it required less time to build a complete map of the environment than the fixed control networks. BERODE is more scalable because it keeps the robots as a single connected network for more time than the fixed control networks. BERODE is more robust because it has a better success rate at finishing the exploration

Design of a COTS MST distributed sensor suite system for planetary surface exploration

The aim of this project is To bring together current commercially available technology and relevant Microsystems Technology (MST) into a small, standardised spacecraft primary systems architecture, multiple units of which can demonstrate collaboration… Distributed “lab-on-a-chip” sensor networks are a possible option for the surface exploration of both Earth and Mars, and as such have been chosen as a model small spacecraft architecture. This project presents a systems approach to the design of a collection of collaborative MST sensor suites for use in a variety of environments. Based on a set of derived objectives, the main features of the study are: What are the fundamental limits to miniaturisation? What are the hardware issues raised using both standard and MST components? What is the optimum deployment pattern of the network to locate various shaped targets? What are the strategic and economic challenges of MST and the development of a sensor suite network? In general, there are few fundamental physical laws that limit the size of the sensor system. Limits tend to be driven by other factors including user requirements and the external environment. A simple breadboard model of the sensor suite consisting current COTS MST components raised practical issues such as circuit layouts, power requirements and packaging. A grid illustrating features of the Martian surface was created. Various patterns of target and sensor clusters were simulated. Overall, for larger target areas, clusters of sensors produced the best “hit rate”. The overall system utilises both wired and wireless communications methods. The I2C protocol has been investigated for intersuite communications. A link has been made between bacteria pools found on Glaciers (Cryoconites) and the possible conditions for life at the Polar Ice Caps of Mars. The investigation of Arctic Cryoconites has been selected as a representative case study that will incorporate all aspects of the project and demonstrate the system design. A comprehensive mission baseline based on this application has been produced, however the system has been designed to enable its use in a variety of situations whilst requiring only minimal modification to the overall design.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Scalable Control of Distributed Robotic Macrosensors

This paper describes a control mechanism by which large numbers of inexpensive robots can be deployed as a distributed remote sensing instrument, and in which the desired large-scale properties of the sensing instrument emerge from the simple pair-wise interactions of its component robots. Such sensing instruments are called distributed robotic macrosensors. Robots in the macrosensor interact with their immediate neighbors using a virtual spring mesh abstraction, which is governed by a simple physics model. By carefully defining the nature of the spring mesh and the associated physics model, it is possible to create a number of desirable global behaviors without any global control or configuration. Properties of the resulting macrosensor include arbitrary scalability, the ability to function in complex environments, sophisticated target tracking ability, and natural fault tolerance. We describe the control mechanisms that yield these results, and the simulation results that we have used to evaluate its efficacy. 1