含变时滞输入的挠性航天器姿态复合控制

Composite Control for Flexible Spacecraft with Time-varying Input Delay

研究含变时滞输入的挠性航天器姿态复合控制问题。其核心思想是通过设计一个时滞依赖的H_∞控制和干扰观测器(DOBC)相结合的复合分层控制结构,实现姿态角和姿态角速度的稳定控制。在内环回路中干扰观测器对挠性附件振动所引起的干扰进行估计并进行前馈补偿,在外环回路设计相应的H_∞控制器对外部干扰进行有效抑制。所提方法可为振动引起的干扰进行精确补偿,减少干扰对控制效果的影响;另外设计了时滞依赖的状态控制器,降低了时滞对姿态的影响。最后,仿真结果表明改进方法能够比较准确地将振动干扰估计出来,同时显示了不同时滞对姿态角和姿态角速度的影响。

This paper focused on the attitude control problem of flexible spacecraft with time-varying input delay. A composite hierarchical control structure, which combined delays dependent H∞ control with disturbance-observer- based control （DOBC）, was designed to achieve a stable control of the attitude angle and attitude angular velocity. In the internal loop, the disturbance observer was used to estimate the main disturbance caused by flexible and to give a feed-forward compensation. While in the external loop, the H∞ controller was applied in order to achieve better dis- turbance suppression effect. The Advantages of the proposed method are： 1 ） the disturbance caused by flexible is compensated accurately to reduce the influence of disturbance effects; 2 ） delays dependent state controller is de- signed to reduce the effects of delay on attitude Finally, the numerical simulation shows conclusion that this algorithm can estimate the main disturbance accurately, and the influences of different time delays on attitude angle and attitude angular velocity of flexible spacecraft.