面向月面原位资源利用的嫦娥五号月壤样品颗粒形态特征研究

Morphological Characteristics Study of Chang’e-5 Lunar Regolith Particles for In-situ Resource Utilization on Moon

摘要:

月壤颗粒形态特征对月面原位挖掘、运输、3D打印等具有重要影响，我国自主获取的嫦娥五号样品可为月球科研站建设等提供月壤关键参数信息。以月面原位资源利用过程关注的月壤颗粒形态特征为目标，利用体视光学显微镜获取了同济大学获批的嫦娥五号月壤颗粒样品图像，构建了一套图像处理和颗粒识别方法，并提出方向差异指数表征颗粒表面粗糙程度，实现了自动提取颗粒边缘并计算其粒度和形态指标。结果表明，所研究嫦娥五号样品颗粒粒径范围为4.36~792.30 μm，均值纵横比为0.66，均值圆形度为0.806，均值方向差异指数为0.111。小粒径颗粒占比大，10 μm以下颗粒占44.19%。颗粒方向差异指数呈近似正态分布，表明大量颗粒表面粗糙程度近似，并存在少量表面较为光滑和粗糙的颗粒。小粒径颗粒大小与纵横比、圆形度均呈负相关，与表面粗糙程度相关性低，大粒径颗粒大小与形态没有相关性。研究还发现嫦娥五号样品比Apollo 11和Apollo 15样品的颗粒的圆形度更小，形态更不规则。

Abstract:

The morphological characteristics of lunar regolith particles have a significant impact on in-situ excavation， transportation， 3D printing， and other processes on the Moon. The samples obtained independently by China’s Chang’e-5 mission can provide key parameter information for the construction of the lunar research station. This paper focuses on the morphological characteristics of lunar regolith particles that are of concern in the process of in-situ resource utilization on the Moon. Optical microscopy was used to obtain images of the Chang’e-5 lunar regolith particle samples approved by Tongji University， a set of image processing and particle recognition methods were constructed， and a directional difference index was proposed to characterize the roughness of the particle surface. The automatic extraction of particle edges and the calculation of their size and morphological indicators were achieved. The results show that the particle size range of the studied Chang’e-5 samples is 4.36~792.30 μm， with an average aspect ratio of 0.66， an average circularity of 0.806， and an average directional difference index of 0.111. Small particles make up a large proportion， with particles below 10 μm accounting for 44.19%. The directional difference index of the particles is approximately normally distributed， indicating that a large number of particles have similar surface roughness， with a small number of particles having smoother or rougher surfaces. There is a negative correlation between the size and aspect ratio， circularity of small particles， and little correlation with surface roughness. There is no correlation between the size and morphology of large particles. The study also found that the circularity of the particles in the Chang’e -5 samples is smaller and the morphology is more irregular in comparison with the Apollo 11 and Apollo 15 samples.