基于改进滑模趋近律的振动基机械臂的有限时间轨迹跟踪控制

Finite-time trajectory tracking control of oscillatory-based manipulators based on an improved sliding mode reaching law

为解决一类振动基机械臂在基座振动影响下的快速轨迹跟踪问题,提出了一种基于改进趋近律的新型滑模控制方法。将基座振动的影响视为系统的不确定外界扰动项;采用拉格朗日法建立了系统的非线性不确定动力学模型;提出一种新型对数幂次滑模趋近律,并结合一种快速终端滑模面,设计了系统的有限时间轨迹跟踪控制器;理论分析与硬件试验验证了所设计控制器的有效性。结果显示,该控制器有效抑制了基座振动的影响,在有限时间内实现了机械臂的精确轨迹跟踪。可见,该研究所提控制算法具有良好的有限时间控制特性及鲁棒性能。

To address the fast trajectory tracking problem of oscillatory-base manipulators,a novel sliding mode control based on an improved reaching law was proposed in this study.The nonlinear uncertain dynamical model of the oscillatory-base manipulator was obtained via Lagrange equations of the second kind,where the base’s term is regarded as uncertain external perturbations.A novel finite-time trajectory tracking control was designed based on an improved logarithmic-power reaching law and the fast terminal sliding surface.The effectiveness of the proposed control was verified theoretically and experimentally.Results demonstrate that the control effectively suppress the influence of the base oscillation,achieving the accurate trajectory tracking of the manipulator in a fast time.It can be concluded that the proposed control has good finite-time characteristic and robustness.