【作者】 赵志国；

【导师】 陆怀民；

【作者基本信息】 东北林业大学 ， 载运工具运用工程， 2005， 硕士

【摘要】 防风固沙草方格铺设机器人是国家863计划项目,对加快我国防治沙漠化进程有着重要的意义。车辆沙漠通过性是当前车辆工程研究中的关键问题,车辆在沙漠中的通过能力如何,将直接影响到草方格的铺设和整机的工作效率,车辆沙漠通过性研究是该课题的重要组成部分。 本文对车辆行走机构与地面相互作用的研究方法进行了总结和归纳,借鉴当前车辆行走机构与地面相互作用问题的研究方法和成果,为防风固沙草方格铺设机器人提供最佳牵引车和草方格铺设机的行走机构。 以内蒙古磴口县乌兰布和沙漠地区的沙土为研究对象,对沙漠沙土的物理性质和力学性质进行了试验研究。根据计算力学的基本理论,利用有限元法,建立轮胎与沙土相互作用的二维有限元模型,利用大型有限元分析软件ANSYS对驱动轮与沙土相互作用进行了数值模拟,得出轮胎作用下沙土变形、应力和位移等变化情况,求出驱动轮与沙土接触区域的各个节点的水平应力之和,从而求出驱动轮的驱动力。 利用半经验方法计算了轮胎与沙土相互作用的阻力理论预测值,并考虑推土阻力和车轮重复通过时对行驶阻力的影响;利用朗金被动土压力理论计算了草方格铺设机横向插刀推沙阻力和利用Bekker提出的承压特性模型计算了纵向滚轮压草阻力。 在内蒙古磴口县乌兰布和沙漠地区进行了承压特性试验,在试验室做了剪切特性试验;通过试验数据,理论上计算出车辆行驶时的驱动力、阻力、牵引性参数,并根据不同滑转率时的驱动力图求出整机实际工作时的滑转率,最终判断该牵引车是否符合该地区通过性的要求。更多还原

【Abstract】 As the national "863" plan project "Paving square straw Robot for preventing sand flow" is meaningful for us to effectively combat land sandy desertification. Passing performance of vehicle, which will influence the straw paving and the efficiency of the mechanism, is a key problem in vehicle engineering .Therefore, Study on it is one of parts in this project.Several methods about studying walking mechanisms-ground interaction were summarized and inducted in this paper. Referencing existing methods and achievements, the writer offers the best towing tractor and walking mechanisms for the paving straw robot.Regard sand-soil of the desert area of Ulan of Dengkou county of the Inner Mongol province as the research object, the writer carries on experimental study to physical property and mechanics nature of it. According to the basic theories of computational mechanics, two dimensional finite element model of the tire-sand interaction is set up through FEA and the numerical simulation to the drive wheel and sand-soil interaction is also carried on through large-scale finite element analysis software ANSYS. Changes under the function of the tire such as sand-soil deformation, stress and displacement, etc. are drawn. Summed up each nodal horizontal stress of the area drive wheel and sand-soil exposed to, thus the driving force of the drive wheel is asked out.Theory predicted value of friction between the tire and sand-soil is calculated out with semi-empirical method. At the same time bulldozing resistance and the influence on driving resistance while the wheels passing repeatedly are considered; The resistance is computed when horizontal insert knife pushes away sand through Rankine’s earth pressure theory is derived. And the other one is computed while the vertical gyro wheel pressing straw is also derived from pressure-sinkage characteristics model put forward by Bekker.Pressure-sinkage experiment is done in desert area of Ulan of Dengkou county of the Inner Mongol province and shear characteristics experiment is done in the laboratory. Through test data, driving force, resistance and drawing parameters are calculated in theory. And according to drive force graph under the different slip rate, the actual one is worked out. Finally, whether this tractor accords with the passing demand in this area is justified.更多还原