控制受限的挠性航天器姿态机动控制和振动抑制

陶佳伟 张涛

摘 要：針对挠性航天器姿态机动过程中存在模型参数不确定性、外界干扰、执行机构饱和受限及挠性附件振动及挠性模态不易直接测量的问题，提出了一种鲁棒自适应控制方法。首先构造挠性模态观测器对挠性模态变量及其变化率进行观测，然后，设计自适应控制律来处理系统中的不确定参数和外界干扰上界。最后，通过引入附加的输入误差系统来补偿执行器的饱和非线性，从而保证所设计的控制力矩不超过执行器的幅值上限。基于李雅普诺夫方法证明了所设计的控制器保证了姿态机动过程的稳定性和挠性模态振动的衰减，最后通过数值仿真验证表明所设计的控制器能够严格满足执行机构的饱和约束，在完成姿态机动控制的同时，有效抑制了挠性附件的振动。

关键词：挠性航天器；姿态机动；模态观测器；振动抑制；输入饱和

DOI：10.15938/j.emc.

中图分类号：V 448.2 文献标志码：A 文章编号：1007 -449X（2018）00-0000-00

Abstract： In this paper， a robust adaptive control scheme is proposed for attitude maneuver and vibration suppression of flexible spacecraft， in which the parametric uncertainty， external disturbances， unmeasured elastic vibration and input saturation are taken into account simultaneously. This controller does not need the knowledge of modal variables. The absence of measurements of these variables is compensated by appropriate dynamics of the controller which supplies their estimates. In addition， the requirements of knowing the system parameters and the unknown bound of the external disturbance in advance have been eliminated by using adaptive updating technique. For handling the input saturation， an anti-windup filter is constructed. Using the error between the saturation output and the desired control input as the input of the designed auxiliary filter， an auxiliary signal is generated to compensate the effect of input saturation and ensure that the control input is bounded. Within the Lyapunov framework， the controller guarantees the stability of the closed-loop system. Numerical simulation demonstrates vibration suppression and accurate rotational maneuver can be accomplished.

Keywords： flexible spacecraft； attitude maneuver； modal observer； vibration suppression； input constraint