發(fā)布時間：2018-03-19 23:08

  本文選題：冗余振動臺　切入點：流量非線性補償　出處：《哈爾濱工業(yè)大學》2015年博士論文　論文類型：學位論文

【摘要】：中國是地震多發(fā)國家,振動臺作為在實驗環(huán)境中可以實現(xiàn)地震信號模擬的試驗設備,廣泛的用于高層建筑、橋梁和大型結構件振動試驗檢測。冗余多軸振動臺可以克服小尺寸縮尺模型所帶來的試驗精度問題,并能評價分析重載大型結構試件的地震破壞機理和結構整體抗震能力。本課題來源于國家自然科學基金項目:“超冗余長行程并聯(lián)驅動地震模擬臺內力耦合機理及其抑制方法研究”以及“超冗余長行程并聯(lián)驅動地震模擬臺模態(tài)建模及壓力鎮(zhèn)定控制機理研究”,對冗余多軸液壓振動臺的柔性基礎耦合、內力耦合和動力學耦合特性進行了深入研究,并提出了相應的解耦控制策略。冗余液壓振動臺激振器伺服閥的流量非線性將導致加速度波形失真現(xiàn)象,為此,本文建立了液壓系統(tǒng)的非線性模型,通過流量壓力的非線性方程設計了其非線性逆模型,實現(xiàn)了流量的非線性補償,仿真結果驗證了其有效性。同時,通過基于狀態(tài)空間的狀態(tài)反饋設計了自由度的三狀態(tài)反饋控制器,并對其穩(wěn)定性進行了分析,給出了理想三階傳遞函數(shù)所對應的三狀態(tài)控制參數(shù)。當冗余振動臺的反力墻柔性較大時,會影響振動臺的整體特性,使得振動臺的頻寬降低。本文建立了柔性基礎耦合下液壓振動系統(tǒng)的模型,通過等效二自由度系統(tǒng)的模態(tài)研究,確定了綜合固有頻率、液壓固有頻率和基礎固有頻率之間的關系,并分析了柔性基礎的參數(shù)對系統(tǒng)動態(tài)特性的影響,改進了常規(guī)的三狀態(tài)前饋控制器。仿真結果表明前饋改進控制可以有效拓展柔性基礎耦合時的系統(tǒng)頻寬。同時,為了提高高頻時正弦信號的跟蹤精度,克服傳統(tǒng)幅相控制參數(shù)設置繁瑣的缺點,提出了新的幅相控制策略。在時域內給出了正弦信號的幅值誤差、相位誤差和零點偏移的辨識公式。結合辨識誤差,建立了三個參數(shù)的迭代序列,在考慮低頻快速性與高頻穩(wěn)定性的基礎上,對迭代速率進行了分段處理,并分別給出了辨識和迭代部分有限狀態(tài)機程序的計算機實現(xiàn)方法。冗余振動臺的液壓缸數(shù)大于控制的自由度數(shù),電液伺服系統(tǒng)間特性不一致會導致系統(tǒng)產生較大的內力耦合。為了分析內力耦合特性,首先建立了單冗余系統(tǒng)在自由度控制下的內力耦合模型,給出了穩(wěn)態(tài)時內力與伺服閥零偏、安裝精度、測量誤差和平臺剛度之間的關系。然后將冗余振動臺的平臺分別沿水平和垂直方向進行網格劃分,建立了其剛柔耦合動力學模型,并對自由度控制下的內力進行了仿真分析。最后根據(jù)穩(wěn)態(tài)時內力與伺服閥零偏的關系,提出了靜態(tài)內力積分補償控制策略來消除穩(wěn)態(tài)內力。對于動態(tài)內力,則在冗余振動臺內力耦合空間分析的基礎上,通過內力合成矩陣,對合成內力進行閉環(huán)反饋補償,由冗余變形分解矩陣將補償量分配到各液壓伺服閥的輸入端,提出了動態(tài)壓力的均衡控制策略。仿真結果表明所提的內力控制方法能有效降低冗余液壓振動臺的靜態(tài)及動態(tài)耦合內力,減少內力控制參數(shù)。冗余振動臺在帶負載工作時,由于負載的偏心,各個自由度之間會出現(xiàn)動力學耦合現(xiàn)象。為此,建立了動力學耦合模型,根據(jù)動力學耦合模型引入耦合力觀測器,經過雅可比矩陣變換,將耦合力分解到各液壓缸上,視耦合力為液壓系統(tǒng)的干擾力進行控制,并給出了干擾力的順饋補償控制策略,提出基于動力學模型下的解耦控制策略�；趧恿W模型的解耦控制需要對加速度反饋信號進行微分處理,由于實際控制時加速度反饋信號的噪聲較大,在此基礎上,提出了模態(tài)的解耦控制策略。將液壓缸視為液壓彈簧,分析了冗余振動臺的自由振動模態(tài)方程,通過模態(tài)矩陣及其逆矩陣,將冗余振動臺由自由度空間轉到無耦合的模態(tài)空間進行控制,從而實現(xiàn)了冗余振動臺的模態(tài)解耦控制。同時通過對模態(tài)矩陣與模態(tài)自由度耦合特性之間關系的分析,給出了實驗確定模態(tài)矩陣的方法。仿真分析顯示,與基于動力學模型的解耦控制相比,模態(tài)空間解耦控制能更有效的降低冗余振動臺自由度間的動力學耦合。基于x PC Target快速控制原型技術開發(fā)了用于控制冗余多軸振動臺的實驗系統(tǒng),對上述各種耦合特性及解耦算法進行了詳細的實驗分析和研究。實驗結果驗證了本文所提出解耦控制策略的先進性和有效性。
[Abstract]:Chinese is an earthquake prone country, shaking table as in the experimental environment can realize the seismic signal simulation test equipment, widely used in high-rise buildings, bridges and vibration test of large structures detection. Redundant multi axis shaking table can overcome the small scale model caused by the test accuracy problem and evaluation analysis of large structure overloading the specimen of earthquake damage the overall seismic mechanism and structure. This subject comes from the National Natural Science Fund Project: "the earthquake simulation platform coupling mechanism and research method as well as the" suppression "super long stroke redundant parallel drive seismic modeling and Simulation Study on the mechanism of modal pressure stabilization control super long stroke" redundant parallel drive, flexible coupling the redundant multi axis hydraulic vibration table, coupling and dynamic coupling characteristics are studied deeply, and put forward the corresponding decoupling control strategy. The flow of nonlinear redundant hydraulic vibration table vibration servo valve will cause acceleration waveform distortion, therefore, this paper establishes a nonlinear model of hydraulic system, nonlinear equation by flow pressure design of the nonlinear inverse model, the nonlinear compensation flow, simulation results verify its effectiveness. At the same time, through the state space. State feedback design of three degrees of freedom based on state feedback controller, and analyzes the stability and control parameters of the three state three order transfer function corresponding to the given. When the redundant shaking table reaction wall flexibility, will affect the overall characteristics of the shaking table, the shaking table to reduce the bandwidth in this paper. The establishment of the hydraulic vibration system of flexible foundation under the coupling model, through the modal analysis of the equivalent of two degree freedom system, determine the comprehensive natural frequency, natural frequency and medium hydraulic The relationship between the basic frequency, and analyzed the influence of parameters of flexible foundation on the dynamic characteristics of the system, improve the state of three conventional feedforward controller. The simulation results show that the system can effectively expand the bandwidth improvement of feedforward control based flexible coupling. At the same time, in order to improve the tracking accuracy of sinusoidal signal frequency, amplitude and phase control to overcome the traditional parameter setting complicated, put forward a new phase and amplitude control strategy. In the time domain is given the amplitude error of sinusoidal signal, the phase error and the offset identification formula of zero. Combined with the identification error, iterative sequence established three parameters, considering the low speed and high frequency stability, the iteration rate the segmentation processing, and implementation methods are presented for identification and iterative part finite state machine program. The hydraulic cylinder vibration control is greater than the number of redundant freedom The degree of the electro-hydraulic servo system between the characteristics of inconsistency will cause the system to produce force coupling is greater. In order to analyze the coupling characteristics of internal forces, internal force coupling model is established firstly single redundant system in degrees of freedom under the control of steady-state internal force and servo valve zero bias, the installation accuracy, the measurement error and the relationship between the stiffness of the platform. Then redundant shaking table platform respectively along the horizontal and vertical direction mesh, establishes the rigid flexible coupling dynamics model, and the internal force under the control of the degrees of freedom were analyzed. According to the steady state of internal force and servo valve bias, the static force integral compensation control strategy to eliminate steady-state internal force for the dynamic force, based on redundant shaking table coupling space analysis, the internal force of the internal force of matrix synthesis, synthesis of closed-loop feedback compensation by redundant deformation The amount of compensation allocation matrix solution to the input end of each hydraulic servo valve, put forward dynamic pressure balancing control strategy. Simulation results show that the force control method proposed can effectively reduce the static and dynamic coupling force of redundant hydraulic vibration table, reduce the internal force of the control parameters. The redundant shaking table with the load when working, because the load eccentricity, between different degrees of freedom will appear dynamic coupling phenomenon. Therefore, to establish the dynamic coupling model, according to the dynamic coupling coupling force observer, by Jacobi matrix transform, the coupling force is decomposed into various hydraulic cylinders, as the coupling force for the disturbance force of hydraulic system control, feedforward compensation and control strategy given the interference force, put forward decoupling control strategy based on dynamic model. The dynamic model of decoupling control of acceleration feedback signal processing based on differential, by In the actual control of acceleration feedback signal noise, based on the proposed modal decoupling control strategy. The hydraulic cylinder for hydraulic spring, analyzed the free vibration modal equations of redundant shaking table, the modal matrix and its inverse matrix, the redundant vibration table consists of DOF space to space without the coupling mode in order to achieve the decoupling control, modal vibration control redundancy. At the same time through the analysis of the relationship between modal matrix and modal degree of freedom coupling characteristic, method of modal matrix experiments are given. The simulation analysis shows that compared with the decoupling control based on dynamic model, modal space decoupling control can effectively reduce the redundant shaking table the dynamic coupling between degrees of freedom. The X PC Target fast control prototype experimental system for control of redundant multi axis shaking table is developed based on the above The coupling characteristics and decoupling algorithm are analyzed and studied in detail. The experimental results verify the advanced and effective performance of the decoupling control strategy proposed in this paper.

【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：P315.8
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本文編號：1636426