# Design of Man-Machine Synergic Lunar Coring Device and Its Coring Dynamic Analysis
## 3 Man-Machine Synergic Lunar Coring Device Scheme Design
### Structure Design of the Coring Device  
#### 3.2.1 Handheld Dual-Mode Coring Device  
The dual-mode coring device mainly includes two methods of coring: impact penetration method and rotary drilling method, and its structural composition is shown in Figure 3a,b.  
In the process of sampling the loose lunar regolith layer, to ensure the stratification of the lunar regolith sample to the maximum extent, the impact penetration method sampling is selected, which mainly relies on the high-frequency impact mechanism to realize the coring function. The high-frequency impact mechanism consists of a drive motor, drive shaft, cylindrical cam, energy storage spring, cam roller, impact hammer, and stop-rotation slider, as shown in Figure 4a. The cylindrical cam and the impact hammer are connected, and the impact hammer can only move axially along the limit groove under the restriction of the stop-rotation slider. The rotation of the drive shaft drives the impact hammer to continuously apply high-frequency impact energy on the coring connection body to realize the downward impact penetration action of the coring tube. Adjusting the speed of the drive shaft can change the impact frequency of the impact hammer.  
When encountering dense layers of lunar soil or hard lunar rocks that cannot be penetrated, the astronauts can activate the rotating mechanism, relying mainly on gearing. The rotation of the gear drives the movement of the rotating barrel, and the coring connector cooperates with the rotating barrel through the slide key, which does not affect its axial movement along the limit slot while rotating with the rotating barrel. The coring connector further drives the coring tube to cut and drill into the denser lunar soil layer, as shown in Figure 4b. If hard lunar rocks are encountered, and the impact penetration method cannot penetrate, the drive motors of the impact mechanism and rotary mechanism are started at the same time. The coring device is converted into rotary-impact drilling and can achieve excellent drilling results by replacing the bottom penetration coring tube with a spiral drilling tube. The working schematic of the astronaut using the handheld dual-mode coring device is shown in Figure 4c.  
The coring tube mainly comprises the sample storage chamber and the debris storage chamber. The sample storage chamber keeps the acquired lunar soil samples in the chamber with stratification. In contrast, the debris storage chamber collects the debris generated during sampling to prevent debris from accumulating in the upper part of the coring tube, which affects the downward penetration of the coring tube and recovery of samples. Therefore, it can effectively reduce the power consumption during the sampling process and improve the sampling efficiency. The inner and outer surfaces of the coring tube are treated to produce a serrated shape, and the rotating cutting teeth set at the bottom can realize the rotating penetration action of the dense lunar soil layer. When a single coring operation is completed and the coring tube is lifted out of the borehole, the debris in the chamber will be discharged out of the tube through the debris removal hole. A schematic  
Figure 3: (**a**) Schematic diagram of the handheld dual-mode lunar coring device; (**b**) Handheld coring device module composition diagram.  
diagram of the internal structure of the coring tube is shown in Figure 5a. Unlike the traditional equal-diameter coring tube and connecting tube, the diameter of the connecting rod in this design is smaller than that of the coring tube. The coring structure is similar to the Luoyang shovel (a coring tool, the shovel body is semi-cylindrical and can penetrate more than ten meters of stratum, commonly used in archaeology and prospecting and other fields), as shown in Figure 5b. During the coring process, only the coring tube of the whole coring device is subjected to the frictional force of the lunar soil, which reduces the frictional power consumption and improves the sampling efficiency.