基于Stewart平台的空间挠性体振动复合控制

Blended Control of Vibrations of Spatial Flexible Bodies Based on Stewart Platform

针对在空间大型挠性体表面布置压电驱动器控制挠性振动时,存在驱动力不足、驱动器安装困难等问题,提出一种在空间挠性体根部安装Stewart平台来控制挠性振动的方法。同时考虑Stewart平台动力学模型和空间挠性体动力学模型的不确定性,建立以Stewart平台跟踪误差和挠性体模态位移为状态量的复合动力学模型。利用LQR(linear quadratic regulator)控制方法设计复合动力学模型的控制律,获得Stewart平台的期望位姿,然后设计Stewart平台运动的滑模控制器,以跟踪期望位姿,实现对挠性体的振动控制。对大型挠性太阳阵进行复合控制仿真研究。结果表明,所采用的基于Stewart平台的空间挠性体振动复合控制方法能够有效抑制太阳阵的挠性振动。

When the piezoelectric controller is arranged on the surface of large spatial flexible bodies to control the flexible vibration,there are the problems of insufficient driving force and installation difficulty.Therefore,a method of installing Stewart platform at the root of the spatial flexible body was proposed to solve the problems.First of all,considering the modeling uncertainties of the Stewart platform dynamics and the spatial flexible body dynamics,a blended dynamic model was established with Stewart platform tracking error and flexible body modal displacement as state variables.Then,the LQR controller was designed to obtain the desired position of the Stewart platform based on the blended dynamics model.And the sliding mode controller of the Stewart platform motion is designed to track the desired position and realize the vibration control of the flexible body.The results of the blended control simulation of a large flexible solar array show that the above method can effectively suppress the flexible vibration of the solar array.