## 2 Architecture and Deployment of the Mobile Robotic Network Developed for Emergency Situations  
The virtualized simulation subcomponent of the robotic network architecture involves the creation of emergency response scenarios and the analysis of experimental data. The need for a simulation environment stems from its ability to generate preliminary results through the abstraction of real-world emergency resolution processes. This subcomponent is integrated into the architecture of a mobile robotic network and connects to its central server via a secure TLS communication protocol, implemented in the form of a ROS Bridge. Figure 1 illustrates the bidirectional link between the robotic network server--deployed within a Kubernetes cluster and simulated using Minikube--and a Hyper-V virtual machine that runs the simulation environment associated with the simulation subcomponent. The Hyper-V virtualization platform was selected to host a virtual machine running Ubuntu 22.04 LTS. Within this environment, ROS2 Humble and the Gazebo simulation framework have been installed and configured. Data exchanged between the virtual machine and the robotic network server are transmitted through ROS2 nodes and topics. Figure 1 also outlines the broader system architecture, which will be developed in a subsequent research phase. The proposed design leverages Kubernetes-based infrastructure and partitions the network's components into three distinct security zones: OT (Operational Technology), DMZ (Demilitarized Zone), and IT (Information Technology). Each of these zones hosts critical elements of the robotic network, including the central server, the web platform, and the relational database management system (RDBMS). Furthermore, a Read-Only application is proposed for deployment within the DMZ security zone. The IT zone will be limited to handling user authentication and registration processes, abstracted via web-based applications. This study focuses on the installation and configuration of the Robot Operating System (ROS) environment alongside the Gazebo simulation framework. In addition, the authors propose the simulation of a locomotion scenario on flat surfaces. The data extracted from the simulation will be transmitted to the Minikube cluster via the WSS protocol, secured using TLS encryption. The mathematical modeling of the robot is based on its unique locomotion system, which comprises four leg-wheel units designed for enhanced terrain adaptability, as illustrated in Figure 2. For the purpose of kinematic analysis, the system is approximated as a four-wheeled skid-steering mobile robot with independent drive units, a common abstraction validated in previous studies [28, 29]. This approximation relies on the geometric equivalence between the hybrid leg-wheel locomotion units (Lu) and a conventional four-wheel skid-steering robot. Figure 1: High-level structural overview of the bridge between Kubernetes cluster and simulation environment. Figure 2: Mobile robot in 2D plane. An inertial reference frame (X, Y) noted with black color, also referred to as the global frame, and a body-fixed frame (x, y) noted with violet color attached to the robot are defined, as illustrated in Figure 3.  
This figure also presents the kinematic diagram of a skid-steering mobile robot, under the assumption that the robot's center of mass coincides with the geometric center of the body frame. Each locomotion unit consists of two extreme wheels that maintain continuous contact with the ground surface. The four extreme wheels, which are in contact with the locomotion surface and located on the same side of the robot, are assumed to rotate at identical angular velocities and have the same angular velocities.