Robot Swarm Navigation and Victim Detection Using Rendezvous Consensus in Search and Rescue Operations

Cooperative behaviors in multi-robot systems emerge as an excellent alternative for collaboration in search and rescue tasks to accelerate the finding survivors process and avoid risking additional lives. Although there are still several challenges to be solved, such as communication between agents, power autonomy, navigation strategies, and detection and classification of survivors, among others. The research work presented by this paper focuses on the navigation of the robot swarm and the consensus of the agents applied to the victims detection. The navigation strategy is based on the application of particle swarm theory, where the robots are the agents of the swarm. The attraction and repulsion forces that are typical in swarm particle systems are used by the multi-robot system to avoid obstacles, keep group compact and navigate to a target location. The victims are detected by each agent separately, however, once the agents agree on the existence of a possible victim, these agents separate from the general swarm by creating a sub-swarm. The sub-swarm agents use a modified rendezvous consensus algorithm to perform a formation control around the possible victims and then carry out a consensus of the information acquired by the sensors with the aim to determine the victim existence. Several experiments were conducted to test navigation, obstacle avoidance, and search for victims. Additionally, different situations were simulated with the consensus algorithm. The results show how swarm theory allows the multi-robot system navigates avoiding obstacles, finding possible victims, and settling down their possible use in search and rescue operations.

Optimal Design and Management of a Hybrid Photovoltaic-Pump Hydro Energy Storage System

The exploitation of renewable sources is an opportunity to increase the number of people who have access to electricity. To assure better living conditions, the free and simple access to water is another fundamental key point in many developing countries. Stand-alone photovoltaic pumping systems are often installed in remote areas where the grid is not available: they are used for irrigation and/or other local water needs and can supply also electricity to small consumers. In this paper a system aimed at supplying electricity and water to an isolated small village has been studied. Ground water is pumped into a storage reservoir and can be used both for irrigation and domestic use. The system is composed by a photovoltaic plant, a pump as turbine (PAT), a diesel internal combustion engine for integration purposes and a battery storage. By means of an optimization model based on the Particle Swarm Theory, the size of the system and its managing strategy have been optimized in order to fulfill the requirement of the users, to improve the system efficiency and minimize the overall costs. The most suitable hourly-based profile of the flow rates of a pump-as-turbine as well was found.

Research of the Temporary Parking Acceleration-Spacing Model Based on Swarm Theory

The disturbance factors in the traffic flow may lead to traffic congestion. The agglomeration characteristics shown in traffic jams are similar to the biological swarm characteristics. In this paper, acceleration-spacing model is established based on the potential field method and the Lagrange method. The vehicle in front is viewed as the main force source. Then the data of the traffic congestion caused by the temporary parking in front of the school are used to calibrate the parameters of the model. It can be verified that the model is effective.

Popular Science and Apocalyptic Narrative in Frank Schätzing’s The Swarm

This paper analyses the use of the rhetoric of the Apocalypse and the concept of nature's revenge in Frank Schätzing's eco-thriller The Swarm. Ecocritical research has identified these narrative patterns as characteristic of contemporary environmental literature. In The Swarm, the apocalyptical rhetoric fulfils the double function of providing thrill and pleasure to the readers and warning them about imminent environmental peril, thereby combining conventions from the two genres of eco-thriller and science fiction. Contrasting reviews have described the novel as either enlightening or pseudo-religious. This ambivalence is the effect of various strategies employed to popularise scientific knowledge in the novel. The narrative embraces various scientific fields, for example the depiction of a network in contrast to swarm theory. The key conflict in the story embodies conflicting concepts of nature - anthropocentric vs. eco-systemic - which are represented by two contrasting groups of characters: one aiming to extinguish the alien superorganism that attacks the human race, the other aspiring to integrate the alien organism into the human world and propagating a holistic view of the Earth. The concepts of a 'tragic' and a 'comical apocalypse' correspond to the double closure which first features a show-down, the annihilation of the 'bad' characters, and then, in the epilogue, a warning message delivered by a 'good' character which confirms - in contrast to, for example, Michael Crichton's State of Fear - the ongoing environmental crisis. Although the epilogue extensively appeals to the human ability to rethink attitudes towards nature, the novel's support for environmental concerns is limited, not only because this message remains rather abstract but also because the vision of a reconciled, pseudo-religious ecosystem as a holistic superorganism has a highly ambivalent meaning for humanity. Resumen Este trabajo analiza el uso de la retórica del Apocalipsis y el concepto de la venganza de la naturaleza en la novela de eco-suspense El Quinto Día de Frank Schätzing. Estudios realizados en ecocrítica han identificado estos patrones narrativos como característicos de la literatura medioambiental contemporánea. En El Quinto Día, la retórica apocalíptica cumple una doble función: proporciona emoción y placer a los lectores y les advierte sobre el peligro ambiental inminente - combinando así las convenciones de los dos géneros de eco-suspense y ciencia ficción. Reseñas opuestas han descrito la novela como instructiva o pseudoreligiosa, siendo esta ambivalencia el efecto de las estrategias variadas para popularizar el conocimiento científico en la novela. El relato abarca diversos campos científicos, por ejemplo, la representación de una red, en contraste con la teoría de enjambres. El conflicto clave en la historia incorpora conceptos contradictorios de la naturaleza - antropocéntrico vs eco-sistémico - que están representados por dos grupos opuestos de personajes: uno con el objetivo de extinguir el superorganismo alienígeno que ataca a la raza humana, y el otro que aspira a integrar al organismo alienígeno en el mundo humano y a propagar una visión holística de la Tierra. Los conceptos de un "apocalipsis trágico y cómico" corresponden con el doble final: en primer lugar se nos presenta una confrontación donde se aniquila a los "malos" personajes y, luego en el epílogo, un mensaje de aviso emitido por una figura "positiva" que confirma la crisis ambiental que continúa - en contraste con, por ejemplo, Estado de Miedo de Michael Crichton.