基于颗粒置换效应的钻取负载动力学行为及原位月壤力学参数辨识

The object of drilling sample mission is regolith on the lunar. The critical particle in the regolith which the size is approximately equal to the drill effect the sample mission. The project aims to research the mechanism of critical particle size replacement in the processing of drilling, and reveal the reason of random vibration of drilling and load change suddenly which caused by size replacement. The two scientific problems are dynamic model of bit cutter and critical particle aggregate interaction, and vibration signals characteristics and load parameters of insitu lunar parameters. The project mainly focus on critical particles movement regulation when cut out of the borehole bottom and pulled into the borehole wall, simulated lunar soil layered and its plastic-elastic model, reflection wave velocity model between critical particles interaction surface, dynamic model of bit cutter and critical particle aggregate interaction, vibration signal characteristics monitoring of drilling and parameters identification of regolith. The characteristic of this project is identify the insitu regolith parameters with limited monitoring parameters. And resolve the fault identification problem caused by critical particle size accumulation. The research results will provide a theoretical support for Lunar sample and manned landing, Mars and asteroids exploration.

月球采样任务的钻进对象是月球表层的土壤，而土层中与钻具结构尺寸相近似的临界尺寸颗粒对采样任务成败的影响很大。围绕取心钻头切削刃与临界尺度颗粒团粒间相互作用的动力学模型以及基于钻具振动信号特征与力载参数的月壤原位参数识别两个科学问题，重点开展临界尺度颗粒在钻孔底部置换流出以及孔壁置换流入的运动规律、构建模拟分层月壤及弹塑性模型、压缩波在临界尺度颗粒滑移面上的反射波波速模型、切削刃切削临界尺度颗粒的动力学模型、钻具振动信号特性监测及土壤参数辨识等研究工作。本项目旨在依据有限的采样状态监测参量，识别月壤钻进极限工况及其原位土壤力学参数，解决因临界尺度颗粒置换不良而引起的钻进状态故障识别问题，为我国探月采样、载人登月、火星探测以及小行星探测等任务提供理论依据。

本项目将月球钻进采样过程中对月壤临界尺度颗粒的运移方式，分为孔底置出和孔壁置入两种。通过研究临界尺度颗粒形貌、与切削刃位置关系、钻进方式等对切削力载的影响，建立了临界尺度颗粒与月壤取心钻头切削刃间相互作用的力学模型，开展了仿真模拟和试验验证，得到了钻具切削临界尺度颗粒的力载变化曲线。基于虚土桩理论建立钻具对月壤冲击作用的力学模型，研究了一维应力波在临界尺度颗粒滑移表面、岩石表面、均质月壤颗粒间的传播规律，通过仿真模拟和冲击试验，得到了上述三种工况下的应力波波形特征曲线，利用傅里叶变换对数据进行整理得到特征图谱。利用回转钻进方式对均质月壤、岩石、临界尺度颗粒月壤进行钻进取芯，得到了特定构型的钻具在面对三种典型工况时的力载表现。基于支持向量机（SVM）方法对临界尺度颗粒的切削负载数据进行辨识研究。通过本项目的研究，揭示了月壤临界尺度颗粒在钻进取芯过程中的运动状态及其对钻进特性（负载和振动）的影响规律，能够识别月壤钻进采样过程中，由于临界尺度颗粒置换不良而引起的钻进状态故障问题。为我国后续嫦娥任务、月球基地建设、火星及小行星探测等任务提供技术支持。