Cooperative object transport with a swarm of e-puck robots: robustness and scalability of evolved collective strategies

Cooperative object transport in distributed multi-robot systems requires the coordination and synchronisation of pushing/pulling forces by a group of autonomous robots in order to transport items that cannot be transported by a single agent. The results of this study show that fairly robust and scalable collective transport strategies can be generated by robots equipped with a relatively simple sensory apparatus (i.e. no force sensors and no devices for direct communication). In the experiments described in this paper, homogeneous groups of physical e-puck robots are required to coordinate and synchronise their actions in order to transport a heavy rectangular cuboid object as far as possible from its starting position to an arbitrary direction. The robots are controlled by dynamic neural networks synthesised using evolutionary computation techniques. The best evolved controller demonstrates an effective group transport strategy that is robust to variability in the physical characteristics of the object (i.e. object mass and size of the longest object’s side) and scalable to different group sizes. To run these experiments, we designed, built, and mounted on the robots a new sensor that returns the agents’ displacement on a 2D plane. The study shows that the feedback generated by the robots’ sensors relative to the object’s movement is sufficient to allow the robots to coordinate their efforts and to sustain the transports for an extended period of time. By extensively analysing successful behavioural strategies, we illustrate the nature of the operational mechanisms underpinning the coordination and synchronisation of actions during group transport

Simulated road following using neuroevolution

This paper describes a methodology wherein genetic algorithms were used to evolve neural network controllers for application in automatic road driving. The simulated controllers were capable of dynamically varying the mixture of colour components in the input image to ensure the ability to perform well across the entire range of possible environments. During the evolution phase, they were evaluated in a set of environments carefully designed to encourage the development of flexible and general-purpose solutions. Successfully evolved controllers were capable of navigating simulated roads across challenging test environments, each with different geometric and colour distribution properties. These controllers proved to be more robust and adaptable compared to the previous work done using this evolutionary approach. This was due to their improved dynamic colour perception capabilities, as they were now able to demonstrate feature extraction in three (red, green and blue) colour channels

Design and analysis of proximate mechanisms for cooperative transport in real robots

This paper describes a set of experiments in which a homogeneous group of real e-puck robots is required to coordinate their actions in order to transport cuboid objects that are too heavy to be moved by single robots. The agents controllers are dynamic neural networks synthesised through evolutionary computation techniques. To run these experiments, we designed, built, and mounted on the robots a new sensor that returns the agent displacement on the x/y plane. In this object transport scenario, this sensor generates useful feedback on the consequences of the robot actions, helping the robots to perceive whether their pushing forces are aligned with the object movement. The results of our experiments indicated that the best evolved controller can effectively operate on real robots. The group transport strategies turned out to be robust and scalable to effectively operate in a variety of conditions in which we vary physical characteristics of the object and group cardinality. From a biological perspective, the results of this study indicate that the perception of the object movement could explain how natural organisms manage to coordinate their actions to transport heavy items

Evolutionary coordination system for fixed-wing communications unmanned aerial vehicles

A system to coordinate the movement of a group of un- manned aerial vehicles that provide a network backbone over mobile ground-based vehicles with communication needs is presented. Using evo- lutionary algorithms, the system evolves flying manoeuvres that position the aerial vehicles by fulfilling two key requirements; i) they maximise net coverage and ii) they minimise the power consumption. Experimental results show that the proposed coordination system is able to offer a de- sirable level of adaptability with respect to the objectives set, providing useful feedback for future research directions

La fortuna di Milziade tra IV secolo a.C. e I d.C. Frammenti di una tradizione

Plutarco e della Seconda sofisitica. Dopo una breve introduzione contenuta nel primo paragrafo, il secondo si sofferma sulle fonti di IV secolo: gli oratori generalmente forniscono una presentazione elogiativa di Milziade, riabilitandone l’immagine dopo la sua morte in disgrazia (par. 2.1); successivamente, viene analizzata la sua presentazione in autori come Platone, Aristotele (par. 2.2) e Teopompo ed Eforo (par. 2.3). Il terzo paragrafo affronta le fonti relative al periodo tra il I sec. a.C. e il I d.C.: l’unica fonte greca è Diodoro (par. 3.1), mentre abbiamo un buon numero di fonti latine, tra cui Nepote, Cicerone, Seneca il Vecchio e Valerio Massimo (par. 3.2). Nel quarto paragrafo sono analizzate alcune notizie isolate su Milziade, relative alla battaglia di Maratona (par. 4.1) o ad eventi ad essa successivi (par. 4.2) o ancora ad altri fatti (par. 4.3), allo scopo non tanto di accertarne l’attendibilità storica, di solito piuttosto bassa, bensì di trarne deduzioni sull’immagine di Milziade che l’autore voleva veicolare attraverso di esse. Il quinto e ultimo paragrafo propone alcune considerazioni conclusive e osserva da un lato che è innegabile una significativa riabilitazione di Milziade, dovuta sia alla propaganda cimoniana, sia soprattutto alla nuova situazione internazionale che Atene si trovava a vivere nel IV secolo, ma, dall’altro, che la sua immagine rimane almeno in parte controversa: sono attestate posizioni critiche, come quella di Platone, e anche giudizi chiaroscurali, come quello di Nepote, autore dell’unica biografia nota di Milziade. This paper focuses on the portrait of Miltiades in the sources between 4th cent. B.C. and 1st A.D., thus after Herodotus and before Plutarch and the Second sophistic. After the first paragraph, devoted to an introduction to the issue, the second one considers sources of the 4th century: the orators usually praise Miltiades and therefore they rehabilitate his reputation after he died in disgrace (par. 2.1); then his figure is analysed in authors like Plato, Aristotle (par. 2.2) and Theopompus and Ephorus (par. 2.3). The third paragraph focuses on the sources between 1st cent. B.C. and 1st A.D.: the only Greek-writing author is Diodorus (par. 3.1), but we have a number of Latin sources, like Nepos, Cicero, Seneca the Elder, Valerius Maximus and others (par. 3.2). In the fourth paragraph it is provided a list of rare pieces of information preserved by the sources, concerning the battle of Marathon (par. 4.1), the events after the battle (par. 4.2) and other episodes (par. 4.3): the aim of this section is not to ascertain the reliability of these pieces of news, that is usually very low, but to use them in order to understand which portrait of Miltiades these sources intended to provide. The fifth paragraph offers final remarks and suggests that, notwithstanding Miltiades’ rehabilitation, due both to Cimon’s propaganda and to the new conditions of 4th century Athens, his imagine remains at least partly controversial: criticisms are attested (e.g. by Plato), but also ambivalent judgments, such as that of Nepos, who wrote the only biography of Miltiades

Integration of Action and Language Knowledge: A Roadmap for Developmental Robotics

“This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”This position paper proposes that the study of embodied cognitive agents, such as humanoid robots, can advance our understanding of the cognitive development of complex sensorimotor, linguistic, and social learning skills. This in turn will benefit the design of cognitive robots capable of learning to handle and manipulate objects and tools autonomously, to cooperate and communicate with other robots and humans, and to adapt their abilities to changing internal, environmental, and social conditions. Four key areas of research challenges are discussed, specifically for the issues related to the understanding of: 1) how agents learn and represent compositional actions; 2) how agents learn and represent compositional lexica; 3) the dynamics of social interaction and learning; and 4) how compositional action and language representations are integrated to bootstrap the cognitive system. The review of specific issues and progress in these areas is then translated into a practical roadmap based on a series of milestones. These milestones provide a possible set of cognitive robotics goals and test scenarios, thus acting as a research roadmap for future work on cognitive developmental robotics.Peer reviewe

Challenges and opportunities of water quality monitoring and multi-stakeholder management in small islands: the case of Santa Cruz, Galápagos (Ecuador)

Sustainable water resources management roots in monitoring data reliability and a full engagement of all institutions involved in the water sector. When competences and interests are overlapping, however, coordination may be difficult, thus hampering cooperative actions. This is the case of Santa Cruz Island (Galápagos, Ecuador). A comprehensive assessment on water quality data (physico-chemical parameters, major elements, trace elements and coliforms) collected since 1985 revealed the need of optimizing monitoring efforts to fill knowledge gaps and to better target decision-making processes. A Water Committee (Comité de la gestión del Agua) was established to foster the coordinated action among stakeholders and to pave the way for joint monitoring in the island that can optimize the efforts for water quality assessment and protection. Shared procedures for data collection, sample analysis, evaluation and data assessment by an open-access geodatabase were proposed and implemented for the first time as a prototype in order to improve accountability and outreach towards civil society and water users. The overall results reveal the high potential of a well-structured and effective joint monitoring approach within a complex, multi-stakeholder framework.publishedVersio