空间双臂机器人抓捕非合作目标后的协调稳定控制

Coordinated stabilization control for dual-arm space robot capturing a non-cooperative target

由于非合作目标惯性参数的不确定性以及双臂操控目标的拉扯/挤压作用,空间双臂机器人稳定非合作目标的过程中机械臂末端与目标可能产生过大的接触力与力矩,从而可能对目标造成损伤。针对该问题,提出了一种协调稳定控制方法,通过协调双臂期望运动实现双臂末端与目标交互的柔顺,降低稳定过程中产生的接触力与力矩。首先,利用目标惯性参数的估值规划稳定运动轨迹;然后,利用柔顺等式建立调整稳定运动轨迹的内外双环,分别针对目标惯性参数不确定性的影响和双臂末端对目标的拉扯/挤压,对期望运动进行调整,得到实现机械臂末端与目标接触柔顺的安全稳定运动轨迹;最后,基于障碍李雅普诺夫函数设计控制性能可约束的跟踪控制器,对双臂的运动进行协调控制,实现机械臂末端与目标交互柔顺的安全稳定控制。仿真算例验证了本文协调稳定控制方法的有效性。

Due to the uncertain target inertia parameters and the internal stress at grasping points, excessive contact wrenches may be applied to the target at grasping points during the stabilization of the non-cooperative target, and therefore the safety of the dual-arm space robot end-effectors cannot be guaranteed. To solve this problem, a coordinated stabilization control scheme is proposed. The desired trajectory of the dual-arm space robot is coordinately adjusted to achieve compliant interactions at grasping points, where the contact wrenches can be reduced during the stabilization process. To realize this coordinated stabilization control, firstly, a desired trajectory is planned with inaccurate parameters of the target. Then, to achieve compliant interactions, a safe stabilization trajectory is obtained by adjusting the desired trajectory with the help of a dual loop structure constructed by compliant equations considering the influences of the uncertain inertia parameters and the internal stress respectively. Finally, to achieve the safe stabilization with compliant interactions, a barrier Lyapunov function based tracking controller is developed to coordinately control the dual-arm space robot, where the control performance can be restrained. The effectiveness and feasibility of the proposed coordinated stabilization control scheme are validated via digital simulations.