基于变幂次对数趋近律的振动基机械臂快速鲁棒控制

Fast robust control of oscillatory base manipulators based on variable power log-reaching law

针对一类安装基座存在不确定随机振动的机械臂系统,提出了一种基于变幂次对数趋近律的快速鲁棒控制策略。基于Euler‐Lagrange方程建立了系统的不确定动力学模型,并将模型中的基座振动项提取出来看作机械臂所受的不确定外部扰动力。提出了一种全新的变幂次对数函数趋近律,既能实现系统状态在远离滑模面时的快速趋近,又能保证在接近滑模面后的抖振能够被有效抑制。在此基础之上,结合一种快速终端滑模面设计了系统的快速鲁棒控制器,进一步提高了系统状态的收敛速度。基于Lyapunov稳定性理论证明了所设计控制器的有限时间收敛特性。搭建了实验平台,通过实验进一步验证所设计控制器的有效性。

A fast robust control strategy based on variable power log-reaching law is proposed for a class of manipulator systems with uncertain random oscillations in the mounting base.The uncertain dynamic model of the system is established based on Euler-Lagrange equation,and the oscillation term of the base in the model is regarded as the uncertain external disturbance force of the manipulator system.A new approach law of variable power logarithm function is proposed,which can realize the rapid approach of the system state far away from the sliding mode surface,and ensure the effective chattering suppression after approaching the sliding mode surface.On this basis,combined with a fast terminal sliding surface,a fast robust controller is designed,which can further improve the state convergence rate of the system.The finite-time convergence of the controller is proved based on Lyapunov stability theory.An experimental platform is built to further verify the effectiveness of the controller.