## 5 Snake Robot Design Considerations for SAR Response Phase
### Control Design  
The control design requirements and ethical considerations mentioned in Section 4 for the SAR-snake robot can be discussed using the ATRA framework [65]. Figure 5 shows the Guidance, Navigation and Control (GNC) interface for the snake robot. In this section, GNC design requirements for SAR operations are explored by considering several ethical issues.  
Figure 4: Illustrating the benefits of the modular design of the snake robot. This makes it possible to: (**a**) achieve locomotion even in the event of a module failure; (**b**) modular reconfiguration (self-assembly) of the snake robot.  
The snake robot's operation is challenging at a low autonomy level (i.e., level 1) because it is controlled remotely via a cord connection. In general, it is not a good idea to operate the robot with a cord because it requires an additional operator to manage it [5]. Hence, adopting higher autonomy levels improves the intervention capabilities by using high-level decision-making, situational awareness through sensors, and better motion control. In [5], [PERSON] et al. recommended establishing mid-layer autonomy between joint-level control and guidance. However, it is still debatable to select the degree of autonomy to operate. For instance, if guidance and navigation give the robot incorrect information and it gets trapped in the terrain. This results in activities being delayed, which is unacceptable for a mission that calls for a fast response. In [106], a guidance model is developed based on the Braitenberg algorithm which guides the snake robot towards a stimulus (i.e., light, sound, chemical, etc.). Similar techniques can be employed for SAR response phase operations to locate the victims or to find the openings in collapsed buildings. With these techniques, some of the responsibility issues can be addressed by properly locating and guiding victims into a safer place.  
Furthermore, complete autonomy in terms of navigation and guidance is desirable and attainable. The full autonomy of snake robots in human-robot interaction (control), however, is up for debate because cognitive technology is not yet at a point where it can comprehend the victim's feelings and emotions. Additionally, it raises various ethical concerns during the interaction, including issues of equality, rights, trust, and accountability. An example ethical dilemma in decision-making while choosing between two distinct kinds of people is shown in Figure 6. Secondly, the robot's gait pattern and movement play a critical role in comforting victims. Therefore, the controller must be designed carefully to maintain suitable gait patterns for each condition without scaring the victim.  
Finally, rescue personnel need to be taught to comprehend the capabilities of the snake robot and various problems that can occur during SAR operations. To do this, the necessary simulation tools must be in place to train personnel and safely test the technology, helping in the adoption of reliable technologies in challenging SAR missions.  
Figure 5: A generalised guidance, navigation, and control architecture for snake robot [65].