Solution of network - induced delay using gpc with predictive error compensation 的網絡控制系統時延補償的研究
The main innovations of this dissertation are summarized as follows : bring forward respectively coding the magnitude and sign of the predictive error of ll subband , which can combined some existing wavelet image codec to improve result 在許多改進和創新下,提出的兩種嵌入式圖像壓縮算法相比于各種流行的小波編碼器,取得了很好的性能,有了較大的突破。
First , calculating time delay and embedding dimension to reconstruct phase space . second , based on chaos theories , the artificial neural network is used to build one - step and multi - steps predictive model . third , combining with an adaptive filter , predictive error is processed so that weak signal is extracted from strong chaotic noise 研究的內容分為三個方面: ( 1 )確定嵌入維數和延遲時間重構相空間; ( 2 )將混沌理論與人工神經網絡結合,建立混沌時間序列(混沌背景)的一步與多步預測模型; ( 3 )結合自適應信號分離器對預測誤差進行處理達到檢測微弱信號的目的。
With pseudorandom binary sequence as inspiriting signal , feedback data is collected and time - domain and frequency - domain characteristic of the steering gear is analyzed . according to the results , system delay is determined . applying predictive error identification method , by comparing the different order model , model structure and parameters of the steering gear is determined 以偽隨機二進制序列為激勵信號,收集了反饋數據;利用收集的數據,對舵機進行了時域和頻域特性分析;并以此為參考,確定了系統的延時量,應用預報誤差的辨識方法,通過不同階次模型間的比較,從而確定了舵機模型結構及參數。
( 2 ) wavelet networks are introduced to gpc . several nonlinear gpc algorithms based on wavelet networks are given : a nonlinear gpc base on predictive error compensation is designed , in which wavelet network is used to model the predictive error ; a new structure of multi - step predictive controller is constructed in which wavelet networks are used to identified the nonlinear directly ; a single - step predictive controller is given , in which a wavelet networks are used to estimate the parameters of the linear time - varying system . ; an a implicit gpc for nonlinear system is presented , in which wavelet networks are used to estimated the time - varying parameters of the generalized predictive controller ( 2 )將小波網絡與非線性廣義預測控制相結合,設計了多種基于小波網絡的非線性廣義預測控制:考慮到建模誤差對多步預報的影響,引入小波網絡估計預報誤差,對輸出預報進行修正,提高了控制性能且不影響系統的穩定性;利用小波網絡構造多步預測器,設討了非線性系統多步預測控制算法;利用小波網絡逼近非線性系統廣義預測控制器的時變參數,設計了非線性系統隱式廣義預測控制器;利用小波網絡辨識時變系統參數并直接用于構造控制器,設計了非線性系統單步預測控制算法。
Prediction algorithm is a most simple one of all methods on images compression . and it explore directly the spectral correlations of hyperspectral images . its method is very simple and easy to be implemented . prediction takes full advantage of the spectral correlations to use transmitted spectral to predict current spectral , then predictive error that original spectral is substracted by predictive spectral is coded . the predictive error is wiped off the spectral correlations , so compression is easier than before 預測技術是最簡單的一種方法,它直接探索譜帶與譜帶之間的相關性,具有算法簡單、易于實現的特點。預測技術充分利用圖像的相關性,用已傳輸的值對當前值進行預測,然后對預測值與真實值的差即預測誤差進行編碼處理。預測產生的殘余誤差已被去相關,因而比較容易壓縮。
Linear predictive control techniques can be applied to nonlinear system for it can be regard as linear time - variant system . multi - model was used in predictive horizon to decrease the predictive error and reflect true state of system . objective function was converted to linear quadratic programming and thus avoid huge computational burden ( 3 )研究了基于t - s模糊狀態空間模型的非線性模糊預測控制方法:利用t - s模糊建模方法,將非線性系統等價為線性時變系統,然后利用線性系統預測控制方法來實現非線性系統的控制。