# Inspection Robot and Wall Surface Detection Method for Coal Mine Wind Shaft
## 3 Overall Design of Tooth Rail Wind Shaft Inspection Robot
### Design of Other Modules
#### 3.4.2 Design of Power Supply Module  
According to the above conclusions, it can be seen that increasing the spacing of I-beams is beneficial to enhance the bearing capacity of the whole structure. From Figure 13, it can be seen that the theoretical optimal value of the solution is (0.837, 1.816), the theoretical design diameter of the tooth rail is about 4 m and the appropriate installation spacing of the tooth rail is 1.674 m. The design parameters of the rack are shown in Table 3. According to the analysis of the power supply mode of the inspection system, it can be seen that the mobile module and the lifting module use a wired power supply, and the detection module uses a battery power supply. Therefore, in order to complete the global inspection of the shaft wall of the wind shaft, it is necessary to select and calculate the batteries involved in the detection module to ensure the reliability of the inspection system. Relatedly, because the intrinsically safe miner's lamp is powered by its own battery, the power consumption equipment of the detection device mainly includes an intrinsically safe camera, ultrasonic ranging sensor and converter. This design is based on the overall inspection strategy, that is, to realize the complete inspection of the shaft wall. After calculation, the circumferential inspection distance of the detection device is about 4.26 m, the circumferential moving speed is about 0.1 m/s, the vertical inspection distance is about 500 m and the vertical moving speed is about 0.2 m/s. As can be seen from the detection area in Figure 15, Point A represents the position of the camera, BC represents the vertical range of the inspection robot, and point D represents the projection point of the inspection camera on the borehole wall. The detection angle of the camera is 120, and the distance from the borehole wall is about 1.0 m. Therefore, the vertical shooting height of the camera is about 3.46 m. In order to avoid error in practical applications and ensure the complete acquisition of the image, the up-and-down shooting height is 3.0 m. For a wind well with a depth of 500 m, the number of up-and-down movements of the robot is about 167, and the number of circumferential inspections is 1600. So, the inspection time \(t_{\text{total}}\) of the inspection robot is  
\[t_{\text{total}}=t_{1}+t_{2}=\frac{4.26}{0.1}\times 168+\frac{3}{0.2}\times 167 =2.68\text{h}\]  
Figure 14: Communication mode of patrol inspection system.  
According to the energy consumption parameters of the power consumption equipment, the battery capacity c calculated by the inspection system is shown in Formula (8), where \(I_{\text{total}}\) always consumes the total current, \(t_{\text{total}}\) always consumes the time and \(\zeta\) is the calculation coefficient, taking 1.5.  
\[C=I_{\text{total}}.t_{\text{total}}.\zeta \tag{8}\]  
According to the known solution conditions, it can be known that the battery capacity requirements are as follows:  
\[C=2.01\text{A}\times 2.68\text{h}\times 1.5=8.08\text{Ah}\]  
Through investigation and analysis, a DXEH8/12 intrinsically safe battery box can be used together with the selected intrinsically safe camera and can be used underground with explosive gases, such as methane and coal dust, with a battery capacity of 8 Ah. According to the above calculation and to ensure the power supply reliability of the inspection system, it is required that the inspection system can meet at least one cycle (progress and return) of inspection operation. Therefore, the required battery capacity is 16.16 Ah, that is, three batteries are required, and the total battery life can reach 8 h.