柔性关节空间机械臂奇异摄动自抗扰控制仿真研究

针对不同重力环境条件下考虑摩擦、关节刚度非线性与外扰影响的柔性关节空间机械臂的控制问题,提出了一种基于奇异摄动理论的自抗扰控制方法。首先建立了柔性关节空间机械臂在地面重力和空间微重力环境下的动力学模型;然后采用奇异摄动法将系统模型分为快变子系统和慢变子系统,针对快变子系统设计速度反馈控制律来抑制柔性关节的振动,针对慢变子系统设计加入前馈补偿的自抗扰控制器(ADRC)来抵抗系统的内外扰动,并对系统进行了稳定性分析;最后对设计的控制器进行了仿真验证与对比研究。仿真结果表明,采用该方法,在不同重力环境下柔性关节空间机械臂均能实现很好的轨迹跟踪和抖振抑制,且能有效抵抗内外扰动,系统具有鲁棒性。

Simulation study of the singular perturbation based active disturbance rejection control for flexible joint space manipulators

A singular perturbation based active disturbance rejection control method considering friction, nonlinear joint stiffness and external disturbance was proposed for control of flexible joint manipulators under different gravity envi-ronments.Firstly, the dynamic model of flexible joint manipulators under the gravity environment and that under the microgravity environment were established.Then, the system model was divided into the fast subsystem and the slow subsystem with the singular perturbation method, and the speed feedback control law was designed to suppress the vibration of flexible joints for the fast subsystem while the active disturbance rejection controller ( ADRC) with a feedforward compensation was designed for the slow subsystem to resist the internal and external disturbance.Al-so, the system stability was analyzed.Finally, the designed controller was verified by simulation and was compared with other control methods.The simulation results show that with the designed controller, the good performance in trajectory tracking and vibration suppression both on the ground and in the space can be achieved, and the internal and external disturbance can be resisted, making the system robust.