Gas-driven Asteroid Regolith Sampling Device Bese On Disk-shaped Cutter

Exploring asteroids and collecting their sample have great scientific and economic significance,and have become one of the hotspot in the field of deep space exploration.In order to collect the sample,an efficient and reliable asteroid sampler is the key to the entire sampling mission.Currently,some domestic and foreign universities and institutions have proposed various forms of samplers and developed principle prototypes,and America and Japan have launched detectors to collect asteroid sample.However,there are some disadvantages about their sampling schemes and their scope of application is narrow.Based on the environment and soil condition of asteroid,this paper proposes an efficient sampler based on disk-shaped cutter and gas driving,which can adapt to a variety of sampling conditions on the premise that the detector has anchored on asteroid.The principle prototype of sampler is developed and sampling experiments are completed.Aiming at crushing the rock on the surface of asteroid and raising the gravel,and based on the model of rock shear fracture and cutting tests of cutters,the cutting force is calculated,and the basic configuration of the disk-shaped cutter and the mechanical structure of power head are designed.Beside,universal joint and leaf spring are designed at the end of the sampler so that the device can adapt to the terrain with a certain inclination and roughness.The transposition mechanism is designed to achieve the function of multi-point sampling,and a feed unit is designed to provide feed force for sampling of the device.Gas driving is the key to transfer the sample.The pressure and direction of current determines whether the particle sample be collected successfully.Based on the gas-driven tests,relevant design parameters are obtained,such as pressure and nozzle diameter.The fluid simulation software is used to analyze the influence of the blowing angle of upper and lower nozzles on the velocity,direction and energy of the gas inside and exit of the cover.The effect of the gas on particle motion is studied by using the coupled simulation of discrete element and fluid simulation software.According to the fluid simulation results at the inside and exit of the cover,the structure of upper and lower nozzles,the components of the pneumatic unit are designed and selected.The principle prototype and experiment bench for the sampling device are developed.By using low density material as the sampling object to simulate the microgravity environment,the influence of nozzle angle on the sampling effect is studied,and the correctness of the simulation analysis is verified.Besides,the experiment is conducted by changing the particle size and material of the sampling objects and simulating undulating terrain under the vertical and horizontal conditions of the experiment bench.Good sampling effects are obtained,and the sampling capability of the device is verified.