基于扩张状态观测器的无拖曳系统参数辨识

Parameter Identification of Drag-free System Based on Extended State Observer

分析了卫星无拖曳控制系统的在轨参数辨识问题,由于无拖曳系统的不稳定性质,需要设计控制器使其稳定,在此基础上进行闭环辨识.根据自抗扰控制原理,设计了扩张状态观测器以估计系统不同控制回路的扰动和状态,基于状态和扰动估计值设计控制器使系统稳定.提出了基于扩张状态观测器(ESO)的多输入多输出系统闭环参数辨识方法.为提高实际应用中的辨识效果,引入积分型滤波器对观测状态中的噪声进行抑制.将这种方法应用于类似LISA Pathfinder的单轴无拖曳模型,对系统动力学参数进行估计,通过数值仿真实验验证了该辨识方法的有效性和实用性.

In this paper, in-orbit parameter identification problem of drag-free control system is studied. Since the drag-free system is not stable, it is necessary to design controllers to stablize this system, then the system can be identificated. According to the principle of active disturbance rejection control, the extended state observer is designed to estimate the disturbance and state of different control loops of the system. Based on the state and disturbance estimation values, the controller is designed to stabilize the system. A closed-loop parameter identification method for multi-input and multi-output systems based on extended state observer is proposed. In order to improve the identification effect in practical applications, the noise in the observed state is suppressed by introducing an integral filter, and the noise suppression mechanism is theoretically explained. Finally, this method is applied to a single-axis non-drag model similar to LISA Pathfinder, and the system dynamics parameters are estimated. The numerical simulation experiments have verified the validity and practicability of the proposed identification method.