# Remotely Controlled Robot Swarms: A Structural Analysis and Model for Structural Optimization
## 3 Results
### The Analysis of Human and Insect Swarm Patterns as a Reference for Robots' Swarm Structures  
A human team of soldiers and insect swarms were chosen for the analyses, as examples of the most and least advanced group structures. A group of soldiers is a hierarchical structure featuring a superior and subordinates. The commander knows the team's task and plans the role of each member of the team. The team moves in an array formation (rows and columns) [17]. In this model, the front (first) row is followed by the second, and so on; each row tryies to walk in the previous row's footsteps. The distance between members is kept at an almost constant value. The members in the next row follow the previous one in their columns. The problem is how to keep the alignment of the rows, so the leader needs to be an example to the front row. The array is set, and the positions of its members are not changeable. During turning, the speeds of soldiers in a row are different and controlled by themselves in reference to their neighbours. A robot in a line has to pay attention to the robot ahead of it in the column, but in the first row the robots' consideration is their distance from the leader and from the other robots in the row. This is not easy, even for human soldiers who are specially trained for it. For such scenarios of movement, we have various functions in the array: the leader, the first row member, and the followers. Therefore, we designed three roles for the robots (Figure 7):  
* The commander, which can be remotely controlled (Master). * The member of the first row who keeps an eye on the position of the commander and follows in line (Slave 1). * The follower who is behind the first row and maintains a set distance from the robot ahead (Slave 2). For robot teams riding through a field, keeping in a straight line is not important in many cases. The simplification of only needing to maintain precise distances between the robots within a column can be effected. A simulation of robot column movement was performed (Figure 8). This simulation involved similar problems to those involved in vehicle platooning. When the leader moved in a straight line, because of various types of resistance, its speed changed. The follower tried to maintain the distance between them by slowing down or speeding up. Due to inertia, this took time, so the distance changed. In the process of distance control, the variability of the motion resistance also applied to the successors. Thus, the actual speed of a given robot was an effect of the instability of its predecessor and its own speed. The farther the robot is from the leader, the more random the speed is, as a result of the many components involved. This is shown in Figure 8. Moreover, when we included the robots' speed, we observed that the distance between them grew. As a result, we could only define leader's position, while the other positions were random. If the distance between robots increases too much, the line may break. Therefore, in order to maintain the line, we needed to control the distance between the leader and the followers, giving higher priority to the distance to the robot behind. Consequently, all the robots moved at a speed no higher than that of the slowest robot. To mitigate this problem, the followers should have a reserve of power to overcome resistance without decreasing their speed and for quick compensation for the growing distance. Variable speeds solved the problem of straight movement. When the leader turned, the followers had to control their position within a certain range of angles. When the leader turned, the follower followed according to the shortest possible path, rather than by simply repeating the leader's path, as shown in Figure 9.  
Figure 8: The distances between the robots changed over time. Figure 7: Basic structure of remotely controlled leader (“Master Robot”) and followers (“Slave Robots”). In an array, the follower has to control the distance to the robots at its sides in order to avoid interference.