控制受限的撓性航天器姿態機動控制和振動抑制

陶佳偉 張濤

摘 要：針對撓性航天器姿態機動過程中存在模型參數不確定性、外界干擾、執行機構飽和受限及撓性附件振動及撓性模態不易直接測量的問題，提出了一種魯棒自適應控制方法。首先構造撓性模態觀測器對撓性模態變量及其變化率進行觀測，然后，設計自適應控制律來處理系統中的不確定參數和外界干擾上界。最后，通過引入附加的輸入誤差系統來補償執行器的飽和非線性，從而保證所設計的控制力矩不超過執行器的幅值上限。基于李雅普諾夫方法證明了所設計的控制器保證了姿態機動過程的穩定性和撓性模態振動的衰減，最后通過數值仿真驗證表明所設計的控制器能夠嚴格滿足執行機構的飽和約束，在完成姿態機動控制的同時，有效抑制了撓性附件的振動。

關鍵詞：撓性航天器；姿態機動；模態觀測器；振動抑制；輸入飽和

DOI：10.15938/j.emc.

中圖分類號：V 448.2 文獻標志碼：A 文章編號：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