• CN:11-2187/TH
  • ISSN:0577-6686

›› 2011, Vol. 47 ›› Issue (1): 43-47.

• 论文 • 上一篇    下一篇

基于滑模控制的空间机器人软硬性抓取

魏承;赵阳;王洪柳   

  1. 哈尔滨工业大学航天学院
  • 发布日期:2011-01-05

Space Robot Soft-hard Grasping Based on Sliding Mode Control

WEI Cheng;ZHAO Yang;WANG Hongliu   

  1. Department of Astronautics, Harbin Institute of Technology
  • Published:2011-01-05

摘要: 采用滑模控制对空间机器人捕获漂浮目标的软硬性抓取进行研究。空间机器人捕获漂浮目标时,由于机械臂与基体的动力学耦合、抓取时的碰撞激振等非线性特性使得抓取控制变得复杂而重要。建立空间机器人及漂浮目标的动力学模型,而后引入末端装置抓取目标时的碰撞模型,并引入“动态抓取域”用于机械臂抓取目标时的控制,随后应用滑模控制及基体姿态控制,以减小抓取碰撞冲击对系统的冲击干扰。滑模面参数表征了机械臂保持及跟踪状态的抗冲击能力,可通过其灵活改变机械臂刚性以获取不同抓取性态,包括接触式硬抓取及碰撞式软抓取。仿真表明,空间机器人捕获漂浮目标过程中,硬抓取能保持机械臂刚性,且关节变化小,末端抓取为持续接触;而软抓取时,机械臂受冲击而随动耗能,关节变化大,但对目标位置及基体姿态的冲击小,均约为硬抓取的50%。抓取性态的研究对空间机器人的捕获操作有着重要的理论及工程价值。

关键词: 动态抓取域, 滑模控制, 空间机器人, 软硬性抓取, 抓取碰撞, 二系垂向悬挂系统, 高速列车, 解析表达式, 留数定理, 振动响应均方根值

Abstract: Sliding mode control is applied in space robot capturing floating target with soft-hard grasping. Capturing operations become quite complicated and important for the nonlinear characteristics such as the dynamic coupling between the arm and the base, the impact excitation during grasping when the space robot captures a floating object. The dynamic model of the space robot and floating target is established, and then the impact dynamic model in grasping is introduced. The dynamic grasping area and the sliding mode control is applied for the arm grasping control to reduce the impact interference to the space robot, while the attitude control of the base with the error quaternion method is used to keep the base stable. The sliding mode surface parameters denote the impact-resistance ability of keeping and tracking status, which can be changed for various grasping characteristics: hard grasping as touching and soft grasping as colliding. The simulation results indicate that hard grasping as continuous contact can keep the arm rigidity as the joints change little, while the soft grasping can make the arm moving for energy dissipation as the joints change a lot, but the impact to the attitude of target and the position of base is little, about 50% that of the hard grasping. The results have important academic value and engineering significance.

Key words: Dynamic grasping area, Grasping impact, Sliding mode control, Soft-hard grasping, Space robot, Analytical formulae, High-speed train, Residue theorem, Root mean square value of vibration response, Secondary vertical suspension system

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