控制受限的撓性航天器姿態(tài)機(jī)動(dòng)控制和振動(dòng)抑制

陶佳偉 張濤

摘 要：針對(duì)撓性航天器姿態(tài)機(jī)動(dòng)過程中存在模型參數(shù)不確定性、外界干擾、執(zhí)行機(jī)構(gòu)飽和受限及撓性附件振動(dòng)及撓性模態(tài)不易直接測量的問題，提出了一種魯棒自適應(yīng)控制方法。首先構(gòu)造撓性模態(tài)觀測器對(duì)撓性模態(tài)變量及其變化率進(jìn)行觀測，然后，設(shè)計(jì)自適應(yīng)控制律來處理系統(tǒng)中的不確定參數(shù)和外界干擾上界。最后，通過引入附加的輸入誤差系統(tǒng)來補(bǔ)償執(zhí)行器的飽和非線性，從而保證所設(shè)計(jì)的控制力矩不超過執(zhí)行器的幅值上限。基于李雅普諾夫方法證明了所設(shè)計(jì)的控制器保證了姿態(tài)機(jī)動(dòng)過程的穩(wěn)定性和撓性模態(tài)振動(dòng)的衰減，最后通過數(shù)值仿真驗(yàn)證表明所設(shè)計(jì)的控制器能夠嚴(yán)格滿足執(zhí)行機(jī)構(gòu)的飽和約束，在完成姿態(tài)機(jī)動(dòng)控制的同時(shí)，有效抑制了撓性附件的振動(dòng)。

關(guān)鍵詞：撓性航天器；姿態(tài)機(jī)動(dòng)；模態(tài)觀測器；振動(dòng)抑制；輸入飽和

DOI：10.15938/j.emc.

中圖分類號(hào)：V 448.2 文獻(xiàn)標(biāo)志碼：A 文章編號(hào)：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