Analysis And Low-gravity Experiment Of Drilled Lunar Soil Sample Transmission Characteristics

China Lunar Exploration Project Ⅲ’s main mission is to let the detector autonomously collect lunar regolith sample and return to the earth, then the detector will obtain deep sample of the lunar soil by drilling method. Drilled lunar soil sample transmission, which refers to the sample container sliding to a sealed container along the guide tube by its gravity on lunar surface, is an important part of China Lunar Exploration Project Ⅲ, related to the success or failure of lunar drilling & sampling. In order to ensure the success of the sample transmission, analysis and low-gravity experiment of drilled lunar soil sample transmission characteristics are needed.In view of the geometric constraints in the process of the sample container transmission, the calculation method of its ultimate position and orientation was given,and the extreme condition of the sealed container relative to the guide cylinder centering positional deviation was analyzed. Then, the sample transmission geometry model was established, and the sample container ultimate contact state with the sealed container was obtained. The sample transmission reliability evaluation method was developed based on the parallel-plate model. The reliability of the current designed transmission mechanism was analyzed. The influence law s of the sample transmission reliability caused by factors such as the guide cylinder length, the sealed container diameter, the sealed container axis position deviation and angular deviation were studied. Some structural parameters suggestions of the sample transmission mechanism to improve the sample transmission reliability were proposed.Based on nonlinear spring-damping contact model, dynamic equation of sample transmission was established. Dynamic modeling and simulation of drilled lunar soil sample transmission were completed by ADAMS software. As a result, the sample transmission characteristics curves under different working conditions and the characteristics of the structural parameters improved trans mission were obtained. The simulation analysis demonstrated the modeling analysis, which provided a new method to the optimum design of the transmission mechanism and the deduction of real sample transmission characteristics.According to geometry features and the mechanical properties of the sample transmission under lunar gravity environment, an indirect segmented equivalent simulation project of the sample transmission under earth gravity environment was proposed and demonstrated. The low-gravity experiment system of sample transmission characteristics was designed, by which the experimental study of sample transmission characteristics under different working conditions was carried out. Experimental results verified the validity of the modeling analysis and simulation results, which provide the references for the optimum design of the transmission mechanism and the deduction of real sample transmission characteristics.