Numerical simulation and experimental research on the wheel brush sampling process of an asteroid sampler

To examine the environmental characteristics of the microgravity force and the weathered layer on an asteroid surface,a symmetric wheel brush asteroid sampler is proposed for the collection of particles on the asteroid surface.To study the influence of the wheel brush rotation speed on the sampling efficiency and the driving torque required for the wheel brush,the contact dynamics model between particles and sampling wheel brushes is established and a simulation and experimental verification of the sampling process are conducted.The parameter calibration of the sampled particles is studied first,and the calibrated particle parameters are used in the numerical simulation of the sampling process.The sampling results and the particle stream curves are obtained for the working conditions of different rotation speeds,and the effects of different parameter settings on the sampling efficiency are analyzed.In addition,a set of rotating symmetrical sampling wheel brush devices is built for the ground test,and the dynamic torque sensor is used to test the torque change of the wheel brush during the sampling process.The relationship between the speed of the wheel brush and the driving torque of the wheel brush motor is determined by comparing the simulation results with the test results.Results indicate that when the rotating speed of the wheel brush is faster,the sampling efficiency is higher,and the driving torque required for the sampling wheel brush is greater.Moreover,a numerical simulation analysis of the sampling process of the wheel brush sampler in a microgravity environment is conducted to determine the optimal speed condition,and the brushing test of the wheel brush sampler in the microgravity environment is verified with the drop tower method.This research proposes the structural optimization design and motor selection of a wheel brush asteroid sampler,which provides important reference value and engineering significance.

轮刷式小行星采样器采样过程仿真与试验研究

基于回转轮刷的刷扫采样是面向小行星表面风化层颗粒的一种新型采样方式,为研究轮刷式小行星采样器的轮刷转速对采样效果的影响,以及采样轮刷所需的驱动扭矩,开展采样器刷扫采样过程的仿真和试验研究尤为必要。研究选取粒径均等的玻璃球颗粒作为采样颗粒,对其进行参数标定,并将标定后的颗粒参数用于数值模拟中,获得采样器在不同转速工况下的采样结果和颗粒流动曲线。同时,搭建一套回转式对称采样轮刷装置进行地面试验,并测试采样过程中轮刷的扭矩变化,对比仿真与试验结果,验证仿真分析的准确性。结果表明,采样轮刷转速越快,采样颗粒质量越多,同时采样轮刷所需的驱动扭矩也越大,其扭矩的波动性也越明显。该研究为轮刷式小行星采样器的结构优化设计与电机选型提供研究思路。