本文關(guān)鍵詞： 線性時變系統(tǒng) 模態(tài)參數(shù)辨識 狀態(tài)空間模型 子空間辨識方法 大型柔性航天器　出處：《大連理工大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：大型柔性航天器結(jié)構(gòu)通常無法在地面進行全尺寸動力學(xué)參數(shù)辨識實驗,而當利用有限元方法對結(jié)構(gòu)進行動力學(xué)分析時,由于模型簡化、計算誤差等影響,難以得到準確的模型參數(shù)。在這種條件下,采用在軌辨識方法,可以更為準確地獲得航天器系統(tǒng)的動力學(xué)參數(shù),從而反映航天器結(jié)構(gòu)的真實運行情況。此外,航天器在軌運行時,大型附件運動、推進劑消耗等因素都可能使得結(jié)構(gòu)的動力學(xué)參數(shù)發(fā)生持續(xù)變化。因此開展航天器時變動力學(xué)參數(shù)的在軌辨識方法研究,不僅可以對已建立的數(shù)值模型進行校驗,還可以為航天器的控制系統(tǒng)設(shè)計與調(diào)整提供參考依據(jù),具有重要的工程應(yīng)用價值。本文考慮大型柔性航天器在軌運行時的動力學(xué)參數(shù)(模態(tài)參數(shù)和狀態(tài)空間模型參數(shù))時變情況,針對航天器周期變化動力學(xué)參數(shù)的辨識、時變模態(tài)參數(shù)和狀態(tài)空間模型參數(shù)的遞推辨識、以及航天器閉環(huán)系統(tǒng)的時變動力學(xué)參數(shù)辨識等內(nèi)容開展了系統(tǒng)地研究。論文主要包括以下幾部分內(nèi)容：(1)研究航天器周期變化動力學(xué)參數(shù)的在軌辨識問題�？紤]航天器大型柔性附件轉(zhuǎn)動對系統(tǒng)動力學(xué)參數(shù)帶來的周期性影響,利用周期子空間方法代替通常的重復(fù)實驗方法,對柔性航天器周期時變的模態(tài)參數(shù)和相應(yīng)的狀態(tài)空間模型參數(shù)進行在軌辨識。仿真結(jié)果證明這種方法能有效辨識航天器的時變動力學(xué)參數(shù)。(2)研究航天器時變模態(tài)參數(shù)的遞推在軌辨識問題,提出了一種提高TW-API遞推子空間方法計算效率的改進方法。首先,針對基于奇異值分解(SVD)的辨識方法計算量較大的問題,采用基于信號子空間投影理論的投影近似子空間追蹤(PAST)、逼近冪迭代(API)和截斷窗逼近冪迭代(TW-API)等三種遞推子空間方法辨識航天器時變模態(tài)參數(shù),并對這三種方法的適用條件和計算效率進行了總結(jié)和比較。然后提出了一種改進的TW-API方法以提高在軌辨識的效率,該方法簡化了數(shù)據(jù)處理中的矩陣遞推過程,在保證計算精度的同時,顯著地減少了在軌辨識過程的計算量,尤其當系統(tǒng)模型的階次較高時,計算效率的優(yōu)勢更加明顯。在數(shù)值仿真中,對改進TW-API方法和基于SVD的周期子空間方法的計算效率進行了比較,證明了遞推子空間方法能夠有效辨識航天器的時變模態(tài)參數(shù),而且具有更高的計算效率。最后,針對上述幾種遞推子空間方法在低信噪比時存在的辨識結(jié)果誤差較大的問題,利用小波降噪技術(shù)對信號進行去噪處理,獲得了良好的辨識結(jié)果。(3)研究航天器時變狀態(tài)空間模型參數(shù)的遞推在軌辨識問題,提出了一種辨識狀態(tài)空間模型參數(shù)中時變輸入矩陣的新遞推格式。不同于常用的重復(fù)實驗辨識方法,新的遞推格式基于信號子空間投影原理,通過重新建立輸入-輸出數(shù)據(jù)之間的關(guān)系,構(gòu)建新的信號子空間矩陣以遞推得到系統(tǒng)的時變輸入矩陣,從而獲得完整的系統(tǒng)時變狀態(tài)空間模型參數(shù)。與現(xiàn)有的基于重復(fù)實驗的辨識方法相比,新的遞推格式不需要進行奇異值分解計算,有效減少了計算時間。(4)研究航天器閉環(huán)系統(tǒng)的時變動力學(xué)參數(shù)在軌辨識問題,提出一種辨識與校驗時變輸出反饋增益矩陣參數(shù)的新遞推格式。新的遞推格式通過構(gòu)建系統(tǒng)的增廣矩陣,利用最小二乘方法計算得到系統(tǒng)的時變輸出反饋增益矩陣。這種遞推格式避免了在直接使用最小二乘方法求逆時可能導(dǎo)致的矩陣參數(shù)辨識結(jié)果不唯一的問題,可以對設(shè)計的反饋增益矩陣參數(shù)進行檢驗。仿真結(jié)果表明提出的遞推格式能夠有效辨識航天器的時變輸出反饋增益矩陣參數(shù)。此外,還對上述的周期／遞推子空間方法在航天器閉環(huán)系統(tǒng)中的應(yīng)用進行了研究,為閉環(huán)系統(tǒng)的時變動力學(xué)參數(shù)辨識問題提供重要的參考。
[Abstract]:Large flexible spacecraft structures usually cannot be on the ground for parameter identification of full size dynamics, and when using the finite element method for dynamic analysis of structures, the simplified model, calculation error, it is difficult to get the accurate model parameters. In this condition, the on orbit identification method can more accurately obtain the kinetic parameters of spacecraft the system, which reflects the real operation of the spacecraft structure. In addition, the spacecraft in orbit, large attachments, fuel consumption and other factors may make the structure of the dynamic parameters of persistent change. So to carry out the spacecraft in orbit identification method of time-varying parameters, can not only verify the numerical model has been established, also can provide a reference for the design and adjustment of spacecraft control system, has important engineering application value. This paper test The kinetic parameters considered for large flexible spacecraft on orbit (the modal parameters and the state space model parameters identification for time-varying), dynamics of spacecraft cycle, recursive identification of time-varying modal parameters and the state space model parameters, and the spacecraft of the closed-loop system and dynamic parameter identification of time-varying system etc. to study. This paper includes the following parts: (1) the change of spacecraft Cycle Kinetic Parameters on orbit identification problem. Spacecraft large flexible rotation periodic impact on system dynamics parameters into consideration, using the periodic subspace method instead of the usual method of repeated experiments, on Orbit Identification of modal parameters of flexible spacecraft and the corresponding periodic time-varying the state space model parameters. The simulation results show that this method can effectively identify the time-varying dynamics of spacecraft. Number. (2) recursive problems in orbit identification of modal parameters of spacecraft when the method is proposed to improve computational efficiency of recursive subspace method to improve the TW-API. For the first, based on the singular value decomposition (SVD) involves a large amount of calculation of the identification method, using projection signal subspace projection based on the theory of approximate subspace space tracking (PAST), the power iteration approximation (API) and truncated window approximation power iteration (TW-API) and other three kinds of modal parameters recursive subspace identification method of spacecraft, and the suitable conditions and the calculation efficiency of the three methods were summarized and compared. Then we propose an improved TW-API method to improve efficiency in orbit identification, this method simplifies the matrix data processing in the recursive process, the accuracy of the guarantee, significantly reducing the amount of calculation in orbit identification process, especially when the high order system model, calculation The efficiency is more obvious advantages. In numerical simulation, the improved TW-API method and the calculation efficiency of periodic subspace methods based on SVD were compared. The modal parameters proved that recursive subspace method can effectively identify the spacecraft, but also has higher computational efficiency. Finally, according to the results of the several recursive subspace identification method in low signal-to-noise ratio error problem of signal denoising by wavelet de-noising technology, obtained good identification results. (3) recursive problems in orbit identification of state space model parameters of the spacecraft, a state space model parameter identification of time-varying input matrix the new recursive scheme. Repeated experimental identification method is different from the commonly used recursive scheme, signal subspace projection based on the new principle, through the re establishment of the relationship between input and output data, Construction of the new signal subspace matrix to achieve recursive system time-varying input matrix, so as to obtain the complete system time-varying state space model parameters. With the existing identification method based on repeated experiments compared with recursive scheme does not require singular value decomposition calculation, effectively reduce the calculation time. (4) study the spacecraft of the closed-loop system time-varying dynamics parameters on orbit identification problems, put forward a method to identify and verify the time-varying output feedback gain matrix parameters of the new recursive scheme. Recursive scheme through augmented matrix system of the new construction, obtained by least square method of time-varying output feedback gain matrix. The recursive scheme to avoid the possibility of lead in the direct use of least squares method to solve the inverse of the matrix parameter identification results not only problem, can test the feedback gain matrix design parameters. The results of the simulation table The proposed recursive scheme can effectively identify the spacecraft time-varying output feedback gain matrix parameters. In addition, the cycle / recursive subspace method of the application in spacecraft closed-loop system are discussed, the closed-loop system with time-varying dynamic parameter identification problem provides an important reference.

【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：V414
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本文編號：1539255