【作者】 李大明；

【导师】 赵阳；

【作者基本信息】 哈尔滨工业大学 ， 飞行器设计， 2012， 硕士

【摘要】 随着国际空间站等结构复杂、功能众多的大型化航天器的广泛应用,其在轨组装、检修、维护成为航天界的焦点问题,在轨服务技术应运而生。由于航天器所处的空间环境特殊,有航天员参与的在轨服务面临诸多困难,因此空间机器人在轨自主装配体现出了明显优势。本文针对空间机器人在轨自主装配的动力学与控制问题展开研究。本文以漂浮基体携带六自由度空间机械臂系统为研究对象,应用DH方法建立机械臂系统各关节坐标系与转换关系,利用递推法进行系统运动学建模,并基于第二类拉格朗日方程对该多体系统进行动力学建模,通过MATLAB编程仿真与商业软件ADAMS进行对比,验证动力学模型的正确性。对空间机械臂系统在轨自主装配过程进行碰撞模型分析与控制模型设计,首先应用末端质量点替代方形可更换模块,用锥形槽等效带楔形角的方形安装孔,简化碰撞模型,并进行碰撞检测分析,引入赫兹弹性模型并计及摩擦力对碰撞力进行计算。应用机械臂操作空间理论进行控制器设计,并进行模块安装与拆卸过程仿真分析,验证了碰撞模型、控制模型的有效性。对自主装配过程的影响因素进行枚举,并应用控制因素法针对引导速度系数、阻尼速度系数、碰撞刚度系数、碰撞阻尼系数、摩擦系数、楔形角度等六个主要影响因素分别进行多组仿真,以装配位置误差、末端碰撞力及基体姿态控制力矩为评价指标,分析各参数对装配过程的影响形式与程度。本文对空间机器人在轨自主装配动力学与控制进行了设计与分析,所得结果可对今后空间机械臂在轨服务等方面提供理论参考,且具有一定的工程应用价值。更多还原

【Abstract】 With the wide application of large spacecrafts such as international space station having complicated structure and numerous functions, on-orbit assembly, examine and repair, preserve have become focus problems in the astronautics field, and the on-orbit service technology develops. For the special space condition of the spacecraft, manned on-orbit service faces many problems, so the on-orbit self-assembling based on space robot shows its obvious advantages. The dynamics and control problems of space robot in self-assembling on orbit are researched in this paper.It is chosen as the research object, a floating spacecraft base bringing a space manipulator with six degrees of freedom. The DH method is used to establish the coordinate systems of the manipulator joints and their conversion relationships. The recursion method is applied for kinematics modeling, and the dynamics model of this multi-body system is established based on the second kind of Lagrange equation. The dynamics model is written to MATLAB program, and the simulation results are compared with the commercial software ADAMS to verify the correctness of the dynamics model.The collision model and control model used in the space manipulator on-orbit self-assembling process are designed. The end mass point is used to replace the square interchangeable module, and the taper slot is equivalent with the square assembling hole with wedge angle, for simplify and collision detection analysis. Hertz elastic model is introduced to calculate the collision force considering the friction force meanwhile. The controller is designed based on the manipulator operation space theory. The validity of the collision model and control model is verified via simulation and analysis of assembling and disassembling process.The influence factors in the self-assembling process are listed. The control factor method is applied on the six main influence factors including leading speed coefficient, damping speed coefficient, collision stiffness coefficient, collision damping coefficient, friction coefficient, wedge angle, to simulate respectively. The assembly position error, the end collision force and the base attitude control torque are considered as evaluation indexes. The influence form and the extent of each factor is analyzed.The dynamics and control of space robot in self-assembling on orbit are designed and analyzed in this paper. The results can provide theoretical reference to the space manipulator technology in on-orbit service in the future, and is of certain value for engineering application.更多还原