漂浮基空间柔性机械臂在轨捕获碰撞分析  

Vibration analysis of a free-floating flexible space manipulator in on-orbit capture collision

作　　者：贾庆轩[1] 洪训超 陈钢[1] 张龙[1] JIA Qingxuan;HONG Xunchao;CHEN Gang;ZHANG Long(School of Automation,Beijing University of Posts and Telecommunications,Beijing 100876,China)

机构地区：[1]北京邮电大学自动化学院,北京100876

出　　处：《振动与冲击》2018年第1期187-195,共9页Journal of Vibration and Shock

基　　金：国家自然科学基金(51305039;61573058;61573066)

摘　　要：针对漂浮基空间柔性机械臂执行抓捕任务过程中的碰撞问题,提出了一种当机械臂末端与目标物发生碰撞时分析系统响应的方法。首先,运用悬臂梁模型和假设模态法建立了考虑臂杆空间柔性变形时空间柔性机械臂的运动学模型;然后,以赫兹阻尼模型模拟软接触碰撞过程,结合拉格朗日方程建立了系统碰撞动力学方程,并推导了关节处于自由和完全受控两种状态时在末端激励下系统的响应方程;最后,通过数值仿真实验分析了机械臂关节处于特定状态下,在末端与目标物产生碰撞接触时漂浮基空间柔性机械臂的响应。数值仿真结果表明空间柔性机械臂在执行在轨捕获任务时,由于接触碰撞产生的碰撞力可能会很大,关节承受力矩甚至可能超过其物理承受极限,同时由于碰撞冲击产生的臂杆位于运动平面内和垂直于运动平面的柔性变形大小相当,在研究柔性机械臂的碰撞响应时应当同时考虑。Aiming at the capture task performed by a free-floating flexible space manipulator, a method for analyzing the system responses caused by the contact between the end-effector of the space manipulator and the target was proposed. Based on the cantilever beam model and the assumed mode method, a kinematics model of the space manipulator considering its flexible links was established. The Hertz damping model was adopted to simulate the soft contact process and according to the Lagrange equation,a contact dynamics model of the space manipulator was also established. On this basis,the response equations of the system due to the external excitation were deduced with its joints free or completely controlled. Finally,the responses of the space manipulator were analyzed by using the numerical simulation with its joints in special state and its end-effector contacting with the target. The numerical simulation results show that when the manipulator performs the capture task,the impact force may be huge,and the forces suffered by its joints may even exceed its limit. Meanwhile,due to the deformations in the motion plane and perpendicular plane caused by the impact are in the same order of magnitude,the impact responses in both planes should be considered.

关 键 词：空间柔性机械臂 悬臂梁 假设模态法 连续碰撞力模型 振动分析 

分 类 号：TP242.4[自动化与计算机技术—检测技术与自动化装置]