## 1 Introduction  
Natural disasters and wars are some of the worst events that humanity has had and will have to face, since in these kinds of situations it is almost impossible to evacuate people in the affected area, causing many more deaths and having a devastating impact. However, the catastrophe is not the only problem, considering that after a catastrophe, the area is still dangerous due to issues such as landslides, debris, damage to the electrical system, and gases, among others. This is a reason rescue teams should be cautious because their lives are still at risk. It causes the survivor search to take longer losing valuable time, which is the most important resource in order to keep survivors alive. It opens the door to some researchers that have taken action in the matter. They involve robotics to help paramedics and rescuers in some tasks, improving their performance. For instance, in [1] they show some advantages, disadvantages, and difficulties that were observed in the use of different robotic platforms that performed SAR (Search And Rescue) tasks on the World Trade Center terrorist attack. This is a good benchmark for research related to this matter that is being developed in recent years and it is present in the robotics road-map. Robotics is presented as a viable alternative thanks to the use of sensors and actuators which allow to minimize human failures. Taking this into account, some works [2; 3; 4] explore the idea of robotics platforms with a hybrid mechanics design. The proposed mechanism allows the robot to navigate on land and air avoiding get stuck in complex environments. Additionally, it is worth highlighting the amount of information that is required to be processed by a single robot in order to satisfying all tasks. Consequently, some researchers focus on the design of semi-autonomous robots as presented in [5; 6]. On the other hand, multi-robot research has shown a different alternative to solve the aforementioned task, for instance, the advantages of using robotic swarms in exploration tasks is mentioned in [7; 8]. Advantages such as coverage of a larger area in less time in contrast to the use of a single platform. In the same way, the robustness and flexibility of the robotic swarm is higher than a single robot, considering that if a robot from the swarm fails or get stuck, the operation and the success of a mission will not be compromised. As was previously mentioned, robotics has become important in SAR operations. Taking into account that by using multi-robot systems some tasks such as exploration, mapping, search and location of victims and classification, among others can be optimized. Tasks related to the exploration of an unknown area become the first important step in wanting to save lives as well as mapping the area to locate victims. The work shown in [9; 10] uses robot network to accomplish navigation and exploration tasks, making use of Voronoi tessellation, and graph theory. On the other hand, it is necessary to take into account the control law that allows a swarm to create attraction towards the victims and repulsion towards obstacles and robots in order to avoid collisions. This approach is achieved using attractive and repulsive potential functions as shown in [11], among other works that have been made to solve the different challenges that entail the exploration task. Taking into account that it is difficult to have access to a real disaster scenario, it is worth mentioning that the present work is carried out by simulation. In robotics, simulation has become an essential tool for research, due to the fact that in recent years simulators have reached a high realistic level in comparison with the real environment as shown in [12]. On the other hand, simulators allow testing algorithms without putting people or equipment at risk. In addition, without losing performance if simulator keeps the necessary characteristics of the real world as shown in [13].