Li Kai, Wang Hesheng, Liang Xinwu, Miao Yanzi
IEEE Trans Cybern. 2022 Nov;52(11):12454-12463. doi: 10.1109/TCYB.2021.3072779. Epub 2022 Oct 17.
Visual servoing and vibration suppression of spatial flexible-link manipulators with a fixed camera setup are addressed in this article. The singular perturbation method is adopted to decouple the dynamic equations of the flexible manipulator; hence, two subsystems that represent the rigid robot motion and flexible-link vibration are obtained, respectively. Then, for the slow subsystem related to the rigid motion, an image-based controller is designed to converge the image errors with the consideration of compensating for the errors of approximating the Jacobian matrix. For the fast subsystem corresponding to the elastic vibration, to eliminate the requirements of measuring the vibration states, an observer is designed to estimate the fast states and then a feedback controller of the fast subsystem is presented to suppress the vibration of the flexible manipulator by using the estimation values. The closed-loop stabilities of the slow and fast subsystem are both proved by employing the Lyapunov theory. Numerical simulations demonstrate the effectiveness of the proposed controller, which shows that the image errors approach zero with the vibration of the flexible manipulator damped out simultaneously.
本文研究了采用固定摄像机设置的空间柔性连杆机器人的视觉伺服与振动抑制问题。采用奇异摄动法对柔性机器人的动力学方程进行解耦；从而分别得到了代表刚性机器人运动和柔性连杆振动的两个子系统。然后，针对与刚性运动相关的慢子系统，设计了一种基于图像的控制器，在考虑补偿雅可比矩阵近似误差的情况下，使图像误差收敛。对于对应于弹性振动的快子系统，为了消除测量振动状态的要求，设计了一个观测器来估计快状态，然后提出了快子系统的反馈控制器，利用估计值抑制柔性机器人的振动。利用李雅普诺夫理论证明了慢子系统和快子系统的闭环稳定性。数值仿真验证了所提控制器的有效性，结果表明图像误差趋近于零，同时柔性机器人的振动得到抑制。
