串联型机械臂的自适应鲁棒容错控制研究

针对串联型机械臂关节空间内的轨迹跟踪控制,提出了一种自适应鲁棒容错控制方法。在机械臂动力学模型中加入了外界干扰、关节摩擦与故障模型,并将其等价成二阶被控系统。在此基础上,结合非奇异快速终端滑模面和反步法控制策略,设计一种新型的反步非奇异快速终端滑模控制器。通过李亚普诺夫准则验证了控制策略的全局渐近稳定性;引入自适应技术估计系统不确定性的上界,提高控制器的鲁棒性。以二自由度机械臂为被控对象,对所设计控制器的有效性进行了验证,结果表明:与传统的非奇异快速终端滑模控制器及反步非奇异快速终端滑模控制器相比,该控制器具有响应速度快、鲁棒性强、抖振小的优点,能有效应对系统故障和实现机械臂的高精度轨迹跟踪控制。

Research for Adaptive Robust Fault Tolerant Control of a Serial Manipulator

Anovel adaptive robust control methodology is developed for tractory tracking control of a manipulator based on a novel adaptive robust control approach.Fault mode, joint friction and external interferences were added in the dynamics mode of manipulator, which was equivalent to secondary system being controlled. In this approach, a novel backstepping nonsingular fast terminal sliding mode controller was designed based on an integration of nonsingular fast terminal sliding mode surface and a backstepping control strategy. The global asymptotic stability of the control strategy was verified by Lyapunov function. Then, an adaptive technique was introduced to estimate the upper bound of system uncertainty and to improve the robustness of the controller. Finally, the effectiveness of the controller designed were verified by using a two degree of freedom (2-DOF)manipulator. The results show that compared with the traditional rapid nonsingular terminal sliding mode controller and backstepping nonsingular fast terminal sliding mode controller, the proposed controller has fast response speed, strong robustness, chattering of small advantages, can effectively deal with system failure and achieve high precision trajectory tracking control of robot arm.