MORFEU

In many disaster situations the human intervention may involve several risks. These threats may derive from different factors such as damaged infrastructures which can potentially collapse at any instant, inflicting damage to working rescue teams. In addition to this, a hazardous environment may also result from broken gas pipes, biohazard materials and other harmful substances.The usage of robotic rescue agents is a powerful tool for rescue operations where no human casualties need to be at risk. These agents can perform common rescue operation tasks and generally operate with reconnaissance purposes, gathering information from many possible sensors. Similarly to a human rescue team, a team of robot agents moves through the disaster impact zone in search of relevant information which may include the search of trapped victims. An important requirement for any rescue team is that some communication infrastructure is always, or at least frequently available. This requirement is fundamental for non-autonomous teams and, particularly, for timely transmission of critical data. The proposed rescue scheme considers multiple robot teams equipped with traditional sensors such as a laser range finder, an omnidirectional video camera and an omnidirectional wireless antenna using the IEEE 802.11 standard. Each team should be remotely controlled, as whole, by a human operator, thus reinforcing the importance of connectivity maintenance. The connectivity requirement should autonomously be met by each individual robot which progressively adjusts its own position in order to optimize the network connectivity. As an additional objective, each robot should also maintain a relative positioning system. The robot position can be obtained through triangulation amongst other team nodes, such that the entire team is aware of all its robots’ positions. Regarding the desired positioning system, one important aspect is that certain nodes, anchor nodes, possess additional positioning information which can be obtained from sensors such as GPS, when available, or even from known reference points when they are identified. As previously explained, there is a hybrid navigation mode for robots, where an entire team is remotely controlled and where within each team there is an autonomous node movement. This movement is based on each robot’s coordinates with connectivity and relative positioning maintenance objectives as a concern. This aspect motivates the need of a communication method that efficiently achieves suitable performance for the correct operation of the mobile nodes. For this purpose, Wireless Mobile Ad-hoc networks are going to be used. As previously explained, there is a hybrid navigation mode for robots, where an entire team is remotely controlled and where within each team there is an autonomous node movement. This movement is based on each robot’s coordinates with connectivity and relative positioning maintenance objectives as a concern. This aspect motivates the need of a communication method that efficiently achieves suitable performance for the correct operation of the mobile nodes. For this purpose, Wireless Mobile Ad-hoc networks are going to be used. Mobile Ad-hoc networks (MANETs) aim at providing a self-configured, self-maintained and self-administrated reliable wireless network without the need of any existent infrastructure. In addition to the support of the already mentioned remote controlled of teams, the final purpose of such network may be different depending on several distinct node objectives. In a rescue situation, a MANET may be used to provide connectivity amongst every agent related with the operation for simple control messages exchange and for supporting all the possible services that these agents may require in order accomplish their mission such as video and audio transmission.Routing protocols represent an important role in how MANETs behave and have a major impact in network performance. Hence, the decision of an appropriate routing protocol is one challenge from which the entire rescue operation may have to rely on. Regarding the proposed rescue approach, the wireless network benefits from the organized robot teams which by themselves keep as an objective maintaining network connectivity. However, from the network perspective, connectivity may not be sufficient to efficiently support the rescue services used during the operations. One important challenge is to analyze the network performance such that, robot nodes are capable cooperate with the routing protocol, helping to achieve the required performance for all the necessary operations by changing their current position according to the existing information. Despite the fact each robot team aims at keeping connectivity between all its nodes, several rescue teams, simultaneously, may be required to target a specific area.