空间网状捕获接口的等效抓捕控制

Equivalent Capture Control of a Space Netting Interface

在空间大型机械臂在轨抓捕过程中,其关节柔性及长臀杆的变形会产生较大的末端跟踪及定位误差,因此很难实现成功抓捕.为此,本文研制了一种空间应用的网状捕获对接接口,提高了大臂末端执行器在大定位误差下的抓捕能力.同时,为了提高末端执行器与目标之间的非相对零速情况下的抓捕性能,利用等效抓捕的思想避开了抓捕过程中捕获接口对目标抓钩纠偏力建模复杂的问题,将问题简化为对目标抓钩端点在捕获面上投影的位置跟踪问题,实现了在末端执行器与目标具有一定的相对逃逸速度的情况下的成功抓捕.实验表明,利用本文提出的控制策略增大了网状捕获接口的抓捕容差范围,从而验证了本文提出的控制策略的何效性.

During on-orbit capture process of a large space manipulator,large tracking and positioning errors of the end effector exist due to the joints＇ flexibility and the distortion of long beams.As a result,it is difficult to realize a successful capture.To solve this problem,a kind of netting interface suitable for space capture application is introduced to improve the end effector＇s capture ability under large positioning errors.Moreover,in order to improve the capture ability,with non-zero relative velocity between the end effector and target,an equivalent capture strategy is put forward to avoid the complexity modeling the interface＇s correcting force on the grapple of the target during the capture process.The proposed strategy simplifies the complicated capture problem into position tracking of the target grapple＇s projection on the capture plane,thus successful capture can be achieved even when a relative escaping velocity exists between the end effector and the target. Experiments show that the proposed strategy can enlarge the tolerance range of the netting capture interface,which proves the effectiveness of the proposed strategy.