本文關(guān)鍵詞： 線性時(shí)變系統(tǒng) 模態(tài)參數(shù)辨識(shí) 狀態(tài)空間模型 子空間辨識(shí)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(lèi)型：學(xué)位論文

【摘要】：大型柔性航天器結(jié)構(gòu)通常無(wú)法在地面進(jìn)行全尺寸動(dòng)力學(xué)參數(shù)辨識(shí)實(shí)驗(yàn),而當(dāng)利用有限元方法對(duì)結(jié)構(gòu)進(jìn)行動(dòng)力學(xué)分析時(shí),由于模型簡(jiǎn)化、計(jì)算誤差等影響,難以得到準(zhǔn)確的模型參數(shù)。在這種條件下,采用在軌辨識(shí)方法,可以更為準(zhǔn)確地獲得航天器系統(tǒng)的動(dòng)力學(xué)參數(shù),從而反映航天器結(jié)構(gòu)的真實(shí)運(yùn)行情況。此外,航天器在軌運(yùn)行時(shí),大型附件運(yùn)動(dòng)、推進(jìn)劑消耗等因素都可能使得結(jié)構(gòu)的動(dòng)力學(xué)參數(shù)發(fā)生持續(xù)變化。因此開(kāi)展航天器時(shí)變動(dòng)力學(xué)參數(shù)的在軌辨識(shí)方法研究,不僅可以對(duì)已建立的數(shù)值模型進(jìn)行校驗(yàn),還可以為航天器的控制系統(tǒng)設(shè)計(jì)與調(diào)整提供參考依據(jù),具有重要的工程應(yīng)用價(jià)值。本文考慮大型柔性航天器在軌運(yùn)行時(shí)的動(dòng)力學(xué)參數(shù)(模態(tài)參數(shù)和狀態(tài)空間模型參數(shù))時(shí)變情況,針對(duì)航天器周期變化動(dòng)力學(xué)參數(shù)的辨識(shí)、時(shí)變模態(tài)參數(shù)和狀態(tài)空間模型參數(shù)的遞推辨識(shí)、以及航天器閉環(huán)系統(tǒng)的時(shí)變動(dòng)力學(xué)參數(shù)辨識(shí)等內(nèi)容開(kāi)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(dòng)力學(xué)參數(shù)的在軌辨識(shí)問(wèn)題�？紤]航天器大型柔性附件轉(zhuǎn)動(dòng)對(duì)系統(tǒng)動(dòng)力學(xué)參數(shù)帶來(lái)的周期性影響,利用周期子空間方法代替通常的重復(fù)實(shí)驗(yàn)方法,對(duì)柔性航天器周期時(shí)變的模態(tài)參數(shù)和相應(yīng)的狀態(tài)空間模型參數(shù)進(jìn)行在軌辨識(shí)。仿真結(jié)果證明這種方法能有效辨識(shí)航天器的時(shí)變動(dòng)力學(xué)參數(shù)。(2)研究航天器時(shí)變模態(tài)參數(shù)的遞推在軌辨識(shí)問(wèn)題,提出了一種提高TW-API遞推子空間方法計(jì)算效率的改進(jìn)方法。首先,針對(duì)基于奇異值分解(SVD)的辨識(shí)方法計(jì)算量較大的問(wèn)題,采用基于信號(hào)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?cái)啻氨平鼉绲?TW-API)等三種遞推子空間方法辨識(shí)航天器時(shí)變模態(tài)參數(shù),并對(duì)這三種方法的適用條件和計(jì)算效率進(jìn)行了總結(jié)和比較。然后提出了一種改進(jìn)的TW-API方法以提高在軌辨識(shí)的效率,該方法簡(jiǎn)化了數(shù)據(jù)處理中的矩陣遞推過(guò)程,在保證計(jì)算精度的同時(shí),顯著地減少了在軌辨識(shí)過(guò)程的計(jì)算量,尤其當(dāng)系統(tǒng)模型的階次較高時(shí),計(jì)算效率的優(yōu)勢(shì)更加明顯。在數(shù)值仿真中,對(duì)改進(jìn)TW-API方法和基于SVD的周期子空間方法的計(jì)算效率進(jìn)行了比較,證明了遞推子空間方法能夠有效辨識(shí)航天器的時(shí)變模態(tài)參數(shù),而且具有更高的計(jì)算效率。最后,針對(duì)上述幾種遞推子空間方法在低信噪比時(shí)存在的辨識(shí)結(jié)果誤差較大的問(wèn)題,利用小波降噪技術(shù)對(duì)信號(hào)進(jìn)行去噪處理,獲得了良好的辨識(shí)結(jié)果。(3)研究航天器時(shí)變狀態(tài)空間模型參數(shù)的遞推在軌辨識(shí)問(wèn)題,提出了一種辨識(shí)狀態(tài)空間模型參數(shù)中時(shí)變輸入矩陣的新遞推格式。不同于常用的重復(fù)實(shí)驗(yàn)辨識(shí)方法,新的遞推格式基于信號(hào)子空間投影原理,通過(guò)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(hào)子空間矩陣以遞推得到系統(tǒng)的時(shí)變輸入矩陣,從而獲得完整的系統(tǒng)時(shí)變狀態(tài)空間模型參數(shù)。與現(xiàn)有的基于重復(fù)實(shí)驗(yàn)的辨識(shí)方法相比,新的遞推格式不需要進(jìn)行奇異值分解計(jì)算,有效減少了計(jì)算時(shí)間。(4)研究航天器閉環(huán)系統(tǒng)的時(shí)變動(dòng)力學(xué)參數(shù)在軌辨識(shí)問(wèn)題,提出一種辨識(shí)與校驗(yàn)時(shí)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(guò)構(gòu)建系統(tǒng)的增廣矩陣,利用最小二乘方法計(jì)算得到系統(tǒng)的時(shí)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(shí)可能導(dǎo)致的矩陣參數(shù)辨識(shí)結(jié)果不唯一的問(wèn)題,可以對(duì)設(shè)計(jì)的反饋增益矩陣參數(shù)進(jìn)行檢驗(yàn)。仿真結(jié)果表明提出的遞推格式能夠有效辨識(shí)航天器的時(shí)變輸出反饋增益矩陣參數(shù)。此外,還對(duì)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(jìn)行了研究,為閉環(huán)系統(tǒng)的時(shí)變動(dòng)力學(xué)參數(shù)辨識(shí)問(wèn)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(jí)別】：博士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：V414
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本文編號(hào)：1539255