## 4 Establishment of the Simulation Test System and Design of Testing Methods  
### Design of the Simulation Test System Architecture  
To guarantee the efficacy of simulation testing, the simulation test system was designed with three major functions: mechanical assembly and motion simulation, electrohydraulic  
Figure 8: Movable path analysis diagram of the tamping device. control system simulation, and process action automatic-execution algorithm simulation. The system architecture is shown in Figure 9.  
In Figure 9, the mechanical assembly and motion simulation function is achieved using SolidWorks to model, assemble, and provide a 3D motion simulation of the SBHS. It can perform a mechanical assembly and motion simulation of key mechanisms, which is the foundation of the entire simulation testing system. The simulation system of the hydraulic cylinder electrohydraulic control system was implemented through the MATLAB platform, which could analyze and simulate the driving process of the hydraulic cylinder, ensure the stability of the hydraulic cylinder speed, and ensure the effectiveness of the process action automatic-execution algorithm testing. The process action automatic-execution algorithm simulation function was implemented through the joint simulation of MSST and SolidWorks [27; 28  
Figure 9: Architecture diagram of SIB process motion simulation testing system. (2) Key parameter collection. To achieve a simulation of the backfilling process, it was first necessary to implement the control of the backfilling hydraulic support model. Therefore, it was necessary to collect the paths of each hydraulic cylinder in the backfilling hydraulic support in real time. For example, the support process required obtaining the front and rear column paths to grasp the front top beam's support height and inclination angle. Key parameters, such as the expansion and contraction quantities of the perforated bottom discharge scraper conveyor, tamping path, tamping angle, and tamping pressure must be obtained in both the unloading and tamping processes. Correspondingly, the distance, angle, and pressure sensors were used, and those sensors were set in the model to monitor the positions [30], as shown in Table 1.  
The installation location and model's data collected by the sensor on the model are illustrated in Figure 12. \begin{table}
\begin{tabular}{c c c c} \hline
**No.** & **Parameter Type** & **Sensor Type** & **Installation Position** \\ \hline
1 & Front column path \(\Delta L_{f}\) & Range sensor & Front-column hinge joint A \\
2 & Rear column path \(\Delta L_{h}\) & Range sensor & Rear-column hinge joint B \\
3 & Front top-beam height \(H_{B}\) & Range sensor & Front top-beam hinge joint C \\
4 & Expansion and contraction quantities of perforated & Range sensor & Scraper and jack hinge joint D \\  & bottom discharge scraper conveyor \(\Delta L_{s}\) & Pressure sensor & Tamping head junction E \\
5 & Tamping pressure \(F_{N}\) & Pressure sensor & Tamping head junction F \\
6 & Tamping path \(L_{0}\) & Range sensor & Tamping head junction F \\
7 & Tamping angle \(q_{1}\) & Angle sensor & Tamping-device hinge joint G \\ \hline \end{tabular}
\end{table} 
Table 1: Monitoring parameter settings and sensor arrangement for the backfilling hydraulic support model. Figure 11: Backfilling hydraulic support SimMechanics model. (3) Cylinder electrohydraulic drive function. The expansion and contraction of each hydraulic cylinder in the backfilling hydraulic support were controlled by an electromagnetic directional valve. The electromagnetic directional valve belonged to a switch valve and its extension/retraction state corresponded to the extension and retraction states of the hydraulic cylinder. The opening time corresponded to a certain number of extension and retraction paths of the hydraulic cylinder.