# Inspection Robot and Wall Surface Detection Method for Coal Mine Wind Shaft
## 2 Challenges and Solutions of Wind Shaft Wall Inspection
### The Solution of the Wind Shaft Wall Inspection System
#### 2.2.2 Design of Long-Distance and High-Flexibility Inspection Mechanism  
According to the analysis of the actual working conditions of the shaft and the simulation experiment, it is known that the visual sensor can obtain the target image clearly at a close range. The lateral radius of the wind shaft is large, so it is difficult to easily locate and obtain clear shaft wall images. It is analyzed that the existing inspection robots for the shaft are mounted on lifting containers such as cages instead of manual inspection. Although many researchers have designed inspection robots with steel ropes and rigid guide rails, which have good controllability, these inspection robots have serious problems, such as a low load capacity and poor endurance, and are not qualified for long-distance shaft inspection tasks. Therefore, this paper proposes to design a long-distance and flexible inspection robot instead of manual inspection and realize its circumferential/axial position \begin{table}
\begin{tabular}{c c c c} \hline  & **Illumination 6 lux, Humidity 55.6\%, 1.5 m,** & & **Illumination 6 lux, Dust Concentration 10–15 mg/m\({}^{3}\),** & \\  & **Shooting Situation under Different Dust Conditions** & & **Shooting Situation is 1.5 m under Different Humidity** \\ \hline
**Serial** & **Dust Loading** & **Shooting Situation** & **Humidity/\%** & **Shooting Situation** \\
**Number** & **(mg/m\({}^{3}\))** & **Shooting Situation** & **Humidity/\%** & **Shooting Situation** \\ \hline
1 & 0 & 60 & 60 \\
2 & 30 & 60 & 70 \\
3 & 50 & 60 & 80 \\
4 & 90 & 90 & 90 \\
5 & 130 & 90 & 90 \\ \hline \end{tabular}
\end{table} 
Table 1: Mapping table of image definition and environmental conditions. ing and long-distance mobile inspection tasks so as to eliminate the occurrence of wellbore accidents in time and greatly improve the safety of coal mine production. However, unlike the ground inspection robot, the inspection robot needs to design a special track if it wants to move laterally/circumferentially. Commonly used tracks are mainly divided into flexible tracks and rigid tracks. Flexible tracks are mainly flexible parts such as steel wire rope and nylon rope. Flexible track has the following characteristics: its advantages are simple structure and convenient installation and maintenance; And has good flexibility and long service life; However, it swings laterally during use; And the spacing between containers and between containers and well wall is required to be large. Rigid track is mainly composed of steel rails, section steel and other structural members. Rigid track has the following characteristics: its advantages are stable structure and long service life; However, its lateral rigidity is small and it is easy to produce vibration. Comparing the characteristics of the two, although the flexible track has a simple structure and convenient installation and construction, it is flexible and has lateral swing. In contrast, the rigid track has a stable structure and a long service life, so it is the first choice for a moving track. Moreover, although the existing shaft inspection robots are mostly based on wire ropes and rigid guide rails, they generally have the problems of low load capacity and poor endurance. Considering that the hoist has the advantages of heavy load, high controllability and good stability, it is considered that the steel wire rope is wound on the drum first, and then the drum drives the steel wire rope to bypass the sheave and pull the lifting container to move up and down to realize lateral movement. According to the characteristics of accurate gear transmission, as shown in Figure 3, the track is designed as an annular toothed rail which is installed at the wellhead and bottom of the wind shaft, respectively, the winding hoist is installed on the toothed rail through the moving module, and the annular toothed rail is used as the moving track so as to realize the circumferential movement of the detection module.