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Modeling And Analysis Of Drilling System Of Sampling Device For Deep Lunar Soil

Posted on:2015-01-08Degree:MasterType:Thesis
Country:ChinaCandidate:W B XuFull Text:PDF
GTID:2180330422991516Subject:Machine and Environmental Engineering
Abstract/Summary:PDF Full Text Request
According to the goal of the third state of China lunar exploration, the originalbedding quality lunar soil which is under2m depth of lunar surface and weighs morethan500g is obtained. The interaction mechanical model between auger and lunar soil,the model of lunar drilling-sampling mechanism and motor is studied in this paper, thecontrol model of drill coupling system is established and the performance of the systemunder different working conditions is analyzed. The research work is mainly presentedas following aspects:First of all, based on Soil Mechanics Theory,movement rule of group of lunar soilparticle flow in effect of auger is studied,consider the radial distribution of lunar soilcharacteristics, force analysis of lunar soil infinitesimal body in surface of auger iscompleted, interaction between bit and lunar soil is studied, acquire the relationshipbetween drilling depth and the critical speed of auger, calculate the coupling coefficientbetween feed rate and rotating speed, the analytical model of auger and bit resistancetorque, supplementary thrust of auger is established, the interaction mechanical modelbetween sampling drill and lunar soil is established.Secondly, according to functional requirements of the lunar soil sampling, drillingmechanism basic project is established. The force of simplified model of loadingmechanism and rotating mechanism is analyzed. The mechanical model of drillingmechanism is established. The mathematical model and the vector control method ofstepper motor is studied, The vector control model of stepper motor is established, Themathematical model and double closed-loop control method of brushless dc motor isstudied, The dual-loop control model of brushless dc motor is established, the dynamicresponse of the motor control model is respectively verified by simulation.Finally, based on the interaction mechanical model between sampling drill andlunar soil, the influence of the depth to the critical speed, the coupling coefficient andfeed rate is analyzed, the influence of the depth and rotation speed to resistance torqueof auger and supplementary thrust is studied, by combining with the mechanical modelof drilling mechanism, the influence of penetration distance to penetrate driving torqueand the depth to resistance torque of bit is analyzed, the influence of the depth andreduction ratio to rotate driving torque. According to the following analysis, rationaldrilling process parameters is selected, based on the performance of the system underdifferent working conditions, the corresponding control strategy is designed.
Keywords/Search Tags:Lunar soil sampling device, Drilling System, Control Strategy
PDF Full Text Request
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