【作者】 陈磊；

【导师】 马杰；

【作者基本信息】 哈尔滨工业大学 ， 控制科学与工程， 2008， 硕士

【摘要】 月球探测车的研制是一项复杂的系统工程,它涉及到众多领域的技术。本文针对新研制的八轮扭杆摇杆转向架式月球车进行多方面基础性研究,为其自主运动和控制提供理论保障和坚实基础。本文首先将对月球车进行运动学分析,分别对轮地接触、整车结构和滑移进行建模,得到适用于崎岖地形的月球车正运动学模型。针对驱动和转向情况对逆运动学模型进行求解,对驱动角速率和转向角速率的计算公式进行推导,并针对不同的地形情况,在Matlab中用优化的方法进行仿真和分析。由于滑转量是月球车在松软的月壤上行驶时所必须考虑的,是运动学滑移模型中的关键参数,然后围绕滑转量的估计,本文将对月球车进行动力学分析——从单个轮的轮地接触机理分析入手,推导出整车的动力学模型,并经过分析和简化推导出以滑转率为状态变量的控制模型。最后,针对以滑转率为状态变量的控制模型,采用滑模变结构理论,将根据指数趋近率方法设计控制器。为减小抖振,需对参数选取进行分析。并基于Matlab/Simulink进行仿真和分析。控制滑转率达到期望值,就可用滑转率的定义式对滑转量进行求解。滑转量的估计完善了月球车的运动学模型,将为其运动控制提供重要参数。更多还原

【Abstract】 The development of lunar rover is a complex systemic project involved many techniques of different areas. This thesis provides some primary development on the platform of eight-wheel rocker-bogie lunar rover with torsion bar. And these are the solid foundation for autonomous motion and control.Firstly,kinematics analysis of the lunar rover is presented in this thesis. Kinematics modeling which is suitable for uneven terrain is combined by tire-soil interaction modeling, rover structure modeling and slip modeling. Drive angle velocity and turning angle velocity can be calculated by inverse kinematics modeling for drive and turning problems. Optimization is being used in simulation with different types of terrains to testify the kinematics modeling in Matlab.Secondly, slip is the key factor in slip modeling. It can not be neglect in the motion of lunar rover on fine grained soil. Dynamics analysis is needed to solve this problem. Dynamics modeling is deduced from tire-soil interaction mechanics. Control modeling with slip ratio as state variable is simplified from dynamics modeling after its analysis.Finally, the exponent approaching sliding mode control is adopted in the controller of the slip control modeling. In order to reduce the chattering, the choice of the coefficient is discussed. Analysis is conducted after the simulation in Matlab. As the slip ratio could be controlled at the expected area, the slip can be calculated by the definition of the slip ratio. So the slip modeling is perfect and it provides important motion information.更多还原