# Design and Dynamic Analysis of the Wire-Line Coring Robot for Deep Lunar Rocks
## 2 Design of the Wire-Line Coring Robot for Deep Lunar Rocks
### Wire-Line Self-Exavating Coring Robot  
The composition of the WSC robot is shown in Figure 3, including the pressure supply part, drilling part, and coring part. The pressure supply part fixes the WSC robot's position in the coring hole and provides drilling pressure. The drilling part provides rotational and impact functions to cut and break the lunar soil/rocks. The coring part stores the lunar soil/rocks coring samples and temporarily stores the debris generated in the coring. The WSC robot is modularly combined to realize the functions of each part. The modular design provides easy control of the size of the WSC robot and facilitates the functional testing of the prototype. The WSC robot is implemented mechanically with core actuators to reduce the energy supply burden, except for the modules that require an active drive. The pressure supply part includes the anchor module which provides the support force in the hole, and the screw module to provide the drilling pressure, as is shown in Figure 4a. The anchor module is provided with three symmetrical crank slider mechanisms and anchor plates fixed on the sliders, where the crank is the same eccentric wheel. Therefore, the anchor plate can be driven by motors to synchronize the expansion, thus ensuring the positional anchoring of the WSC robot. To avoid anchor plate rebound during coring, a ratchet locking device is installed in the anchor module. The locking device is unlocked with the rope retrieval force so that the anchor plate can be retracted when the WSC robot is lifted. The locking device enables the anchor module to require less energy after deployment. Thus, the WSC robot can provide a higher energy supply for the drilling relative to other telescopic coring devices, such as the autonomous tethered core. The drilling part consists of the redirection module, the impact module, the rotation module, and a force sensor, as shown in Figure 5a. The redirection module has the ability to drive the WSC robot to shift direction actively in the hole so that the WSC robot can avoid extreme drilling situations, as shown in Figure 5b. The impact module generates the impact force through the spring energy storage mechanism. The application of the impact force can improve the drilling efficiency and reduce the torque for drilling the rocks. The force sensor is used to obtain real-time data on the axial force and rotational torque to make preliminary judgments on the current drilling situations. Figure 3: Design of the WSC robot. The coring part can be divided into the debris-tolerant chamber, the connection module, the coring tube module, and the bit module, as shown in Figure 6. The coring part is a purely mechanical structure with the potential to be applied to other celestial bodies, such as Mars. Due to the load limitation of the aerospace mission, a consumable drilling fluid is not used to dispose of the debris that is generated during the coring process. Therefore, the debris-tolerant chamber is designed to temporarily store the debris. To dispose of the debris, the combination of the connection module and the debris-tolerant chamber enables the WSC robot to automatically discharge the debris after releasing the coring tube. Additionally, compared to other wire-line coring devices without waste chip handling, the setup of the debris-tolerant chamber significantly increases the length of the coring robot. However, debris increases the drilling resistance and leads to large amounts of debris in the subsequently collected samples. The connection module is designed with a heart-shaped slot and a spring, which enables the connection module to switch between the locked and unlocked states through a single application and unloading of the unidirectional Z-axis force.